Contents
1 Introduction
2 Basic Format Concepts
2.1 Data Variables
2.2 File Header Variables
3 Notation
4 Definitions
5 ASCII File Format Specifications
5.1 FFI = 1001
5.2 FFI = 1010
5.3 FFI = 1020
5.4 FFI = 2010
5.5 FFI = 2110
5.6 FFI = 2160
5.7 FFI = 2310
5.8 FFI = 3010
5.9 FFI = 4010
5.10 Summary of data record formats
6 Version 2 Format Extensions
6.1 ONAME
6.2 ORG
6.2.1 Organizations
6.3 SNAME
6.3.1 Platforms
6.3.2 Instruments
6.4 MNAME
6.5 XNAME(s), ANAME(a), VNAME(n)
6.5.1 Geolocation Subjects
6.5.2 Geolocation Qualifiers
6.5.3 Geophysical Subjects
6.5.4 Geophysical Qualifiers
6.5.5 Platform Qualifiers
6.6 Normal Comment Lines
6.6.1 Signal Version 2 extensions
6.6.2 Conversion to Standard Units
6.6.3 Normal Comment Numeric Data
6.6.4 Normal Comment String Data
6.7 Standard Units
7 Format Examples
7.1 FFI=1001
7.2 FFI=1010
7.3 FFI=1020
7.4 FFI=2010
7.5 FFI=2110
7.6 FFI=2160
7.7 FFI=2310
7.8 FFI=3010
7.9 FFI=4010
Steven E. Gaines and R. Stephen Hipskind
gaines@cloud1.arc.nasa.gov and steve.hipskind@nasa.gov
Version 2.0
2006-01-01
1 Introduction
This document describes a conceptual framework for specifying exchange
data formats, and then gives a detailed description of the standard
formats. Those considering writing exchange files must review the
format options presented in this document and determine the format
most suitable for recording their data. If none are deemed suitable
then consult with the project archive manager for assistance with
either recasting data into an existing format or defining a new format
option.
The primary goal of instituting format standards for data exchange
is to promote accessibility and ease of use of a variety of datasets
from different instruments, platforms and numerical models. Toward
that goal, exchange files must be self-describing and readable on
all commonly used computer systems, using a minimal amount of software.
An additional advantage of standardized file formats is that data
files can more effectively be automatically screened for format errors
before they are archived. The system described here uses ASCII files
because ASCII coded files are readable on all of the common computer
systems, and they are convenient in the sense that there are a variety
of software tools which can be used to view and manipulate ASCII files.
This document also introduces some backward-compatible extensions
to the original 1990 format specification. Computer programs which
were designed to read an arbitrary file in the original format will
also be able to read files in the formats described herein, both with
and without the format extensions, although those programs will have
to be modified to utilize the additional information supplied by the
extensions. The format extensions merely provide more specific conventions
for constructing the file header character string variables, and the
added information can be used to facilitate automated processing of
exchange files.
Perhaps the most fruitful way to learn about the file formats is to
first review the concepts in Section
2 and then concentrate
on the format recipes in Section
5, with reference
to the notation and variable definitions in Sections
3
and
4. The format extensions are described in Section
6, and examples of each file format, without and with
the format extensions, are in Section
7. Since any particular
format option can accommodate a variety of types of data, the concepts,
terminology, and format specifications are first presented in an abstract
manner so not to bias or narrow their definition. The examples in
Section
7 are included to provide a tangible link between
the abstract definitions and actual exchange data files. It will,
therefore, be useful to refer to these examples while (or before)
reading the rest of this document.
2
Basic Format Concepts
For our purposes, ASCII exchange files are considered to be a sequence
of printable ASCII characters, organized into lines, with each line
terminated by one or two non-printable ASCII control characters.
- Different types of operating systems use different control characters
as line terminators: Unix-like systems use the <LF> character (ASCII
decimal value 10); DOS/Windows systems use <CR><LF> characters (ASCII
decimal values 13 and 10); the older Macintosh systems use the <CR>
character.
Two general constraints on the way lines are constructed in all ASCII
exchange files are:
- Aside from appropriate line terminators, only printable ASCII characters
are allowed in the file. The printable characters have ASCII decimal
values 32 through 126. Thus, horizontal TABs and other control characters
are not allowed.
- The maximum number of printable ASCII characters allowed in each line
is 132.
The specific constraints on how characters are arranged in a file
are dictated by the particular file format, as specified in Section
5. Each ASCII data file consists of a file header,
followed by the data records. The file header is used to describe
the data and the origin of the file.
Both the file header and the data records consist of values of predefined
variables, with each variable having a predefined type: character
string or numeric. Numeric values are further classified as either
integer or real numbers. Of course, a numeric value is also just a
string of ASCII characters, but it is restricted to consist of only
those characters used to express integer or real numbers, as defined
in Section
4.
A character string variable value occupies an entire line, so line
terminators delimit successive character string values. Successive
numeric variable values are delimited by either one or more spaces
or by a line terminator. However, as you will see in Section
6,
the format extensions call for dividing values of the character string
variables in the file header into fields, and interpreting the contents
of each field as either a number or a character string. So in those
special cases the field delimiter can also delimit successive numeric
and character string values.
2.1 Data Variables
The data are conceptually divided into
Independent Variables
and
Dependent Variables.
Independent Variables are further
classified as either bounded or unbounded, and
Dependent Variables
are further divided into
Primary and
Auxiliary Variables,
as outlined below:
- Independent Variables
* bounded
* unbounded (IVM)
- Dependent Variables
* Auxiliary Variables
** function of only the unbounded Independent Variable
* Primary Variables
** function of all Independent Variables
The number and types of
Independent Variables and the types
of
Dependent Variables in a particular file are determined
by the particular format of the file, as specified in Section
5.
The
Independent Variable with the largest index (1 if there
is only one
Independent Variable, 2 if there are two, etc.)
is the unbounded variable. The other
Independent Variables
(if any) are the bounded variables. Values of the unbounded variable
are always explicitly recorded in the data records, and given the
special name: Independent Variable Marks (IVM).
Auxiliary Variables
are functions of only the unbounded variable, whereas
Primary
Variables are considered to be single-valued functions of all
Independent
Variables.
To ensure that single-valuedness, all
Independent Variables
are required to have monotonic values. In other words, successive
values of each
Independent Variable must either continually
increase or continually decrease. There are a few file formats for
which values of the bounded
Independent Variable are not constant
throughout the file and can vary with each IVM, and in those cases
the requirement is to use monotonic values of the bounded variable
for each IVM.
Within the constraints of the predefined file formats, investigators
have considerable leeway to choose a file format and their data variables.
Data variable values can be either real numbers or character strings,
depending on the particular format used to construct the file, and
while it is often natural, and desirable, to use geolocation parameters
as
Independent Variables, that is not a requirement.
Our discussions of variables will often differentiate between the
number of variables and the number of values of a particular variable,
and it is important to recognize the distinction between the two.
To illustrate, consider a file which uses altitude and time as the
bounded and unbounded
Independent Variables, so the number
of
Independent Variables is two. If 60 values of altitude are
recorded in the file then the number of values of the bounded variable
is 60.
2.2 File Header Variables
The file header is used to describe the data and the origin of the
file. The first line in the file header includes the File Format Index
(FFI) which, with reference to the format recipes in Section
5,
determines the general format of the rest of file header and the data
records. Several character string variables are used to specify information
about the originators of the file and the primary source of the data
within the file. Other variables are used to describe the
Independent
and
Dependent Variables, and to define missing values and scale
factors for the
Dependent Variables.
- You will notice that there are no missing values or scale factors
associated with Independent Variables. Each Independent
Variable value must be a valid value.
The file header also allows for three types of comments. Two of these
comment types have reserved locations within the file header, and
are associated with counters defining the number of lines occupied
by each type of comment (which can be zero). The first type, called
Special Comments, are reserved to note special problems or
circumstances concerning the data within a specific exchange file,
and the revision history for the dataset. The second type are called
Normal Comments, and they can be used for more complete descriptions
of the variables, instrument and originators of the file, or other
comments that apply in general to all of a particular kind of dataset.
The third type of comments are merely annotations which may follow
numeric values; these comments must be contained on the same line
as, and separated by at least one space from the last numeric value
expected in the record. These annotations should not be included in
lines containing character string values because the annotations cannot
easily be separated from the character string values.
3
Notation
The array and implied loop notation, used to generalize the exchange
file format definitions given in Section
5 will now
be explained. The notation is merely a convenient means of specifying
the file formats, and not intended to indicate useful or desirable
array structures in computer programs. The descriptions are from the
perspective of reading exchange files by following the format recipes
in Section
5.
Variables enclosed in square brackets
[ ] are read with
one "read" statement and, therefore, the values
occupy one record. If the value is a character string then the record
encompasses only one line in the exchange file. If the values are
numeric then the record may exceed one line; the implication being
that as many lines as necessary will be read in order to gather the
required number of values.
One or more variables appearing in a line, and not enclosed in square
brackets, are read as one record and constitute one line in the exchange
file.
The indices act as counters to indicate a particular array element,
and thus the dependence of some variable. Several indices are consistently
used for special purposes:
- s
- is the counter for the Independent Variables.
Its range of values is expressed as s=1,NIV, which means
that s may have integer values from 1 to NIV.
When s=NIV (the number of Independent Variables) it
references the unbounded Independent Variable.
- m
- is used to count Independent Variable Marks (IVM), which
are the recorded values of the unbounded Independent Variable,
and m can be the index of any IVM within the file.
- n
- is the counter for the Primary Variables and can
assume values in the range n=1,NV, where NV is the
number of Primary Variables.
- a
- is the counter for the Auxiliary Variables and
can assume values of a=1,NAUXV, where NAUXV is the
number of Auxiliary Variables.
The usage of other indices (
i,j,k) is less consistent, but
usually those indices are used to count array elements of the bounded
Independent Variables. Indices are counted from one (1-relative).
To illustrate the notation, consider the array
X which contains
values of the
Independent Variables.
- X(i,m,s)
- is the general expression for an arbitrary element
of X, where i, m, and s can assume
any allowable values. This expression indicates that values of the
bounded Independent Variables depend on the unbounded Independent
Variable, and can be different at each IVM. The allowable indices
are in the range i=1,NX(m,s), s=1,NIV, which states that
s may take on integer values of 1 to NIV,
and i may assume integer values of 1 to NX(m,s).
The index m can be the index of any IVM within the file.
The variable NX(m,s) is the number of values of the s-th
Independent Variable at the m-th IVM.
- X(i,s)
- is the more common expression for X and
indicates that values of the bounded Independent Variable are
fixed throughout the entire file. The allowable indices are in the
range i=1,NX(s), s=1,NIV.
Now consider the array
V which contains values of the
Primary
Variables.
- V(X,n)
- is the general expression of V, indicating
its dependence on X but not specifying the number of Independent
Variables (NIV). The allowable values of n are
in the range n=1,NV.
- V(i,m,n)
- is an expression for V when there are
two Independent Variables (NIV=2). The range of n
is always n=1,NV, and m can be the index of any
IVM, but the range of i will depend on whether or not values
of the bounded Independent Variable depend on m. If
they do then the range is i=1,NX(m,1); if they do not then
i=1,NX(1).
To continue the illustration, consider the data record format for
FFI=2010:
[ X(m,2) ( A(m,a), a=1,NAUXV ) ]
[ V(i,m,n), i=1,NX(1) ] n=1,NV
- X(m,2)
- represents the m-th IVM for the unbounded
Independent Variable (since NIV=2).
- A(m,a)
- is the value of the a-th Auxiliary
Variable at the m-th IVM.
- V(i,m,n)
- is the value of the n-th Primary
Variable at the m-th IVM and i-th bounded Independent
Variable value.
The square brackets enclosing the first line of the expression indicate
that an IVM and values of
NAUXV Auxiliary Variables
are read as one record which may span more than one line. The second
line of the expression is to be interpreted to mean that for the
m-th
IVM there are
NV records of
Primary Variables, which
will be read with
n starting at a value of
1, incrementing
by one for each record, and ending with a value of
NV for
the last record. The notation within the square brackets indicates
that for each record,
NX(1) values of the
n-th
Primary
Variable at the
m-th IVM are read. In this case, the constant
values of the bounded
Independent Variable (
X(i,1), i=1,NX(1))
are obtained from the file header.
When considering the implied loop notation, like
a=1,NAUXV,
be aware that if the terminal value of the loop is smaller than the
initial value then the loop is not executed. For example, if
NAUXV=0
then only
X(m,2) would be read in the first record of the
above format expression, because there would be no
Auxiliary
Variables.
To be more specific with the FFI=2010 example, assume there are three
Auxiliary Variables (
NAUXV=3), two
Primary Variables
(
NV=2), and four values for the bounded
Independent
Variable (
NX(1)=4). Given these values for the loop limits,
the general expressions for the data format imply the following record
structure (the intra-record spacing between values is merely for illustration):
X(m,2) A(m,1) A(m,2) A(m,3)
V(1,m,1) V(2,m,1) V(3,m,1) V(4,m,1)
V(1,m,2) V(2,m,2) V(3,m,2) V(4,m,2)
X(m+1,2) A(m+1,1) A(m+1,2) A(m+1,3)
V(1,m+1,1) V(2,m+1,1) V(3,m+1,1) V(4,m+1,1)
V(1,m+1,2) V(2,m+1,2) V(3,m+1,2) V(4,m+1,2)
X(m+2,2) A(m+2,1) A(m+2,2) A(m+2,3)
...
If
NAUXV=0 then the resulting data records would be the same
as those depicted above, except there would be no
Auxiliary
Variable values recorded in the records containing the IVM (
X(m,2),
X(m+1,2), etc.).
4
Definitions
- A(m,a)
- is the value of the a-th Auxiliary
Variable at the m-th IVM (a=1,NAUXV). If A(m,a)
is real, the use of ASCAL(a) to record its values as scaled
whole numbers is encouraged.
- AMISS(a)
- is the value which indicates missing, erroneous
or unreliable data for the a-th Auxiliary Variable.
The value of AMISS(a) defined in the file header is the same
value which appears in the data records for missing/bad values of
A(m,a). The value of AMISS(a) must be the largest
value of A(m,a) recorded in the file, so that any value smaller
than AMISS(a) is considered valid data.
- ANAME(a)
- is a character string, on one line, describing
the a-th Auxiliary Variable, A(m,a). Include
the units of measure the data will have after multiplying recorded
values of A(m,a) by the a-th scale factor, ASCAL(a).
- Version 1.x:
- The original specification allows a free-form description.
- Extension:
- The format extensions require a more specific format
for ANAME(a); see Section 6.5 for details.
- ASCAL(a)
- is the scale factor (real) by which one multiplies
recorded values of the a-th Auxiliary Variable to
convert them to the units specified in ANAME(a).
- character string
- is the term used to describe the value of a variable
which consists of a string of at most 132 printable ASCII characters.
The printable ASCII characters have ASCII decimal values from 32 to
126.
- Version 1.x:
- The original specification requires that each character
string value occupy a line, so that line terminators delimit a character
string value.
- Extension:
- The format extensions use both line terminators and field
separators, |, to delimit character string values.
- DATE
- specifies the UTC date at which the data within the
exchange file begins. For aircraft data files DATE specifies
the UTC launch date. DATE is in the form YYYY MM DD
(year, month, day) with each integer value separated by at least one
space. For example, 30 November 1988 can be expressed as: 1988 11 30
- DX(s)
- is the interval (real) between successive values
of the s-th Independent Variable, X(i,s),
i=1,NX(s); in the same units as specified in XNAME(s). DX(s)=0
for a non-uniform interval. DX(s) is non-zero for a constant
interval. If DX(s) is non-zero then it is required that NX(s)=(X(NX(s),s)-X(1,s))/DX(s)+1.
For some file formats the value of DX also depends on the
unbounded Independent Variable and is expressed as DX(m,s).
- FFI
- is the file format index (integer). The FFI uniquely defines
the file header and data formats. It is the second value recorded
on the first line of an exchange file. The first (left-most) digit
in the FFI gives the number of Independent Variables listed
in the file header, the second digit gives the number of required
(in the sense that they are necessary for reading the subsequent data
records) Auxiliary Variables. The remaining digits are used
to loosely associate file formats with similar characteristics.
- Independent Variable Mark
- is a value of the unbounded Independent
Variable which is explicitly recorded in the data records. Independent
Variable Marks (IVM) must be monotonic.
- integer
- is a whole number written without a decimal point. Leading
zeros are insignificant. The characters which can be used to express
integer values are: +-0123456789
- IVM
- is the acronym for Independent Variable Mark.
- IVOL
- is the volume number (integer) of the total number
of volumes required to store a complete dataset, assuming only one
file per volume; to be used in conjunction with NVOL to allow
data exchange of large datasets requiring more than one volume of
the exchange medium (diskette, etc.). IVOL and NVOL
are legacies from the "sneakernet" days, so barring exceptional
cases, IVOL=NVOL=1.
- LENA(a)
- is the number of characters (integer) used to record
Auxiliary Variable A(m,a) when A(m,a) is
represented as a character string. 0<LENA(a)<133.
- LENX(s)
- is the number of characters (integer) used to record
Independent Variable X(i,s) when X(i,s) is
represented as a character string. 0<LENX(s)<133.
- line
- refers to a string of printable ASCII characters within an
exchange file, terminated by the appropriate end-of-line (or new line)
designator for the operating system on which the file resides. The
maximum number of printable characters per line is 132.
- MNAME
- is a character string specifying the mission which
the data is supporting. The appropriate value for MNAME will
be decided upon prior to the start of the mission.
- NAUXC
- is the number of Auxiliary Variables (integer)
whose values are recorded as character strings. If NAUXC=0
then no Auxiliary Variables are recorded as character strings.
- NAUXV
- is the number of Auxiliary Variables (integer).
If NAUXV=0 then no Auxiliary Variables are recorded
and no missing values, scale factors, or names for the Auxiliary
Variables are present in the file header.
- NCOM(k)
- represents a character string occupying the k-th
Normal Comment line (k=1,NNCOML).
- NIV
- is the number of Independent Variables (integer)
on which the Primary Variables are dependent.
- NIVM
- is the number of Independent Variable Marks in the
exchange file. With all formats except FFI=1020, NIVM is
also the dimension of the unbounded Independent Variable.
- Version_1.x:
- In the original specification, NIVM is not
recorded in the file and its value must be found by reading the entire
file and counting the number of Independent Variable Marks.
- Extension:
- NIVM is recorded in a Normal Comment
metadata declaration, as described in Section 6.6.
- NLHEAD
- is the number of lines (integer) occupied by the
file header. NLHEAD is the first recorded value on the first
line of an exchange file.
- NNCOML
- is the number of Normal Comment lines (integer)
within the file header, including blank lines. Normal Comments
are those which apply to all of a particular kind of dataset, and
can be used to more completely describe the contents of the file.
If NNCOML=0 then there are no Normal Comment lines.
- Extension:
- The format extensions provide a convention for metadata
declarations in the Normal Comment lines, and require that
there be at least two Normal Comment lines; see Section 6.6
for details.
- NSCOML
- is the number of Special Comment lines (integer)
within the file header. Special Comments are reserved to note
special problems or circumstances concerning the data within a specific
exchange file so they may easily be found and flagged by those reading
the file. The revision history of the dataset should also be included
in the Special Comments. If NSCOML=0 then there are
no Special Comment lines.
- NV
- is the number of Primary Variables (integer)
in the exchange file.
- NVOL
- is the total number of volumes (integer) required
to store the complete dataset, assuming one file per volume. If NVOL>1
then each volume must contain a file header with an incremented value
for IVOL, and continue the data records with monotonic Independent
Variable Marks. IVOL and NVOL are legacies from
the "sneakernet" days, so barring exceptional cases, IVOL=NVOL=1.
- NVPM(s)
- is the number of Independent Variable values
(integer) between Independent Variable Marks, for the s-th
Independent Variable. NVPM(s) is only used in FFI=1020, and
for that format NVPM(s)=(X(m+1,s)-X(m,s))/DX(s), with s=1.
- NX(s)
- is the number of values (integer) for the s-th
Independent Variable. In some formats, NX(s) is defined
in the file header and specifies the constant number of values for
the s-th bounded Independent Variable. Otherwise,
NX=NX(m,s) is defined in the data records as an Auxiliary
Variable and its values can vary with the Independent Variable Marks.
- Version 1.x
- In the case of an unbounded Independent Variable,
NX(NIV) is never specified in the file but the values of
X(m,NIV) are read from the data records (Independent Variable
Marks).
- Extension:
- NIVM is recorded in a Normal Comment
metadata declaration (see Section 6.6), and for all formats
except FFI=1020, NIVM=NX(NIV).
- NXDEF(s)
- is the number of values (integer) of the s-th
Independent Variable which are explicitly defined in the file
header. If NXDEF(s)=NX(s) then all values of X(i,s),
i=1,NX(s) are recorded in the file header. If NXDEF(s)=1
then only the first value, X(1,s), is recorded in the file
header and the remaining values of X(i,s) are calculated
as X(i,s)=X(1,s)+(i-1)*DX(s) for i=2,NX(s).
- ONAME
- represents a character string specifying the name(s)
of the originator(s) of the exchange file, last name first, on one
line.
- Extension:
- The format extensions require a more specific format
for ONAME; see Section 6.1 for details.
- ORG
- represents a character string specifying the organization
or affiliation of the originator of the exchange file. Can include
address, phone number, email address, etc., on one line.
- Extension:
- The format extensions require a more specific format
for ORG; see Section 6.2 for details.
- RDATE
- represents the date of data reduction or revision,
in the same form as DATE.
- real
- refers to a real valued number that may include a decimal point
or be written in exponential notation. It is preferred that the values
of real numbers be limited to seven significant digits within the
magnitude range of 1.0E-38 to 1.0E+38. The allowable characters in
a real number representation are: +-.0123456789Ee
- record
- refers to a logical record to be read by one "read"
statement, which in general may span more than one line. The first
character of a record is also the first character of a line.
- SCOM(k)
- represents a character string occupying the k-th
Special Comment line (k=1,NSCOML).
- SNAME
- represents a character string which specifies the
source of the measurements or model results recorded in the file.
Can include instrument name, measurement platform, etc.
- Extension:
- The format extensions require a more specific format
for SNAME; see Section 6.3 for details.
- V(X,n)
- represents the value of n-th Primary
Variable (n=1,NV) as a function of the Independent
Variable(s) X. If V is real then the use of VSCAL(n)
to record its values as scaled whole numbers, without decimal points,
is encouraged. Depending on the number of Independent Variables,
V(X,n) may also be expressed as: V(m,n), V(i,m,n),
V(i,j,m,n), V(i,j,k,m,n).
- VMISS(n)
- represents a quantity indicating missing, erroneous
or unreliable data values for the n-th Primary Variable.
The value of VMISS(n) defined in the file header is the same
value that appears in the data records for missing/bad values of V(X,n).
The value of VMISS(n) must be the largest value of V(X,n)
recorded in the file, so that any value smaller than VMISS(n)
is considered valid data.
- VNAME(n)
- represents a character string, on one line, which
specifies the name and/or description of the n-th Primary
Variable, V(X,n). Include units of measure the data will
have after multiplying recorded values of V(X,n) by the n-th
scale factor, VSCAL(n).
- Version 1.x:
- The original specification allows a free-form description.
- Extension:
- The format extensions require a more specific format
for VNAME(n); see Section 6.5 for details.
- VSCAL(n)
- represents the scale factor (real) by which one
multiplies recorded values of the n-th Primary Variable
to convert them to the units specified in VNAME(n).
- X(i,s)
- represents the i-th value of the s-th
Independent Variable (X(i,s), i=1,NX(s), s=1,NIV).
For some file formats the values of a bounded Independent Variable
may also depend on the unbounded Independent Variable, and
in those cases we will denote the bounded Independent Variable
as X(i,m,s), with s<NIV. Values of X(i,s),
i=1,NX(s) and X(i,m,s), i=1,NX(m,s) must be monotonic.
- XNAME(s)
- represents a character string, on one line, specifying
the name and/or description of the s-th Independent
Variable. Include units of measure and order the Independent
Variable names such that, when reading Primary Variables from
the data records, the most rapidly varying Independent Variable
is listed first and the most slowly varying Independent Variable
is listed last.
- Version 1.x:
- The original specification allows a free-form description.
- Extension:
- The format extensions require a more specific format
for XNAME(s); see Section 6.5 for details.
5
ASCII File Format Specifications
This Section contains cookbook recipes for each ASCII data file format,
ordered by increasing file format index (FFI). For each FFI there
is a brief description of the variables and format, followed by a
symbolic representation of the file header and a general expression
for the data records. The variables used to construct the file header
and the data records are defined in Section
4, and
the notation used in this Section is described in Section
3.
Occasionally, lower case characters, preceded by several periods,
are used to annotate certain variables.
5.1 FFI = 1001
One real, unbounded Independent Variable (NIV=1).
Primary Variables are real.
No Auxiliary Variables.
Independent and Primary Variables are recorded in the
same record.
NLHEAD 1001
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(1)
XNAME(1)
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
[ X(m,1) ( V(m,n), n=1,NV ) ]
5.2 FFI = 1010
One real, unbounded Independent Variable (NIV=1).
Primary Variables are real.
Auxiliary Variables are real.
The Independent and Auxiliary Variables are in the same
record.
All Primary Variables for a given Independent Variable Mark
are recorded in the same record.
NLHEAD 1010
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(1)
XNAME(1)
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NAUXV
[ ASCAL(a), a=1,NAUXV ]
[ AMISS(a), a=1,NAUXV ]
[ ANAME(a) ] a=1,NAUXV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
[ X(m,1) ( A(m,a), a=1,NAUXV ) ]
[ V(m,n), n=1,NV ]
5.3 FFI = 1020
One real, constant increment, unbounded Independent Variable
with implied values between Independent Variable Marks (NIV=1).
Primary Variables are real.
Auxiliary Variables are real.
The Independent and Auxiliary Variables are in the same
record.
A record of Primary Variable values at implied Independent
Variable values is recorded for each Primary Variable.
NLHEAD 1020
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(1) .............. DX(1) not equal to zero
NVPM(1)
XNAME(1)
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NAUXV
[ ASCAL(a), a=1,NAUXV ]
[ AMISS(a), a=1,NAUXV ]
[ ANAME(a) ] a=1,NAUXV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
[ X(m,1) ( A(m,a), a=1,NAUXV ) ]
[ V(i,n), i=1+(m-1)*NVPM(1),m*NVPM(1) ] n=1,NV
5.4 FFI = 2010
Two real Independent Variables (NIV=2); one unbounded,
and one bounded with constant values defined in the file header.
Primary Variables are real.
Auxiliary Variables are real.
Independent Variable Mark and Auxiliary Variables are in the
same record.
For each Primary Variable is a record of its values at the
bounded Independent Variable values.
NLHEAD 2010
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(1) DX(2)
NX(1)
NXDEF(1)
[ X(i,1), i=1,NXDEF(1) ]
[ XNAME(s) ] s=1,2
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NAUXV
[ ASCAL(a), a=1,NAUXV ]
[ AMISS(a), a=1,NAUXV ]
[ ANAME(a) ] a=1,NAUXV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
[ X(m,2) ( A(m,a), a=1,NAUXV ) ]
[ V(i,m,n), i=1,NX(1) ] n=1,NV
5.5 FFI = 2110
Two real Independent Variables (NIV=2); one unbounded, and
one bounded with its values recorded in the data records.
Primary Variables are real.
Auxiliary Variables are real; A(m,1)=NX(m,1) which
defines the number of bounded Independent Variable values to
be read from the records following the m-th Independent Variable
Mark.
The values of X(i,m,1) are included in the records with the
Primary Variables.
If NX(m,1)=AMISS(1) or NX(m,1)=0 then the implication
is that the records containing values of the bounded Independent
Variable and Primary Variables are omitted, and the next record
contains the succeeding Independent Variable Mark and Auxiliary
Variables.
NLHEAD 2110
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(1) DX(2)
[ XNAME(s) ] s=1,2
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NAUXV ................. The first auxiliary variable is NX(m,1)
[ ASCAL(a), a=1,NAUXV ]
[ AMISS(a), a=1,NAUXV ]
[ ANAME(a) ] a=1,NAUXV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
[ X(m,2) NX(m,1) ( A(m,a), a=2,NAUXV ) ]
[ X(i,m,1) ( V(i,m,n), n=1,NV ) ] i=1,NX(m,1)
5.6 FFI = 2160
Two Independent Variables (NIV=2); the unbounded Independent
Variable is a character string of length LENX(2); the bounded
Independent Variable is real with its values recorded in the
data records.
Primary Variables are real.
The Independent Variable Mark is in a separate record from the Auxiliary
Variables.
The value of the first Auxiliary Variable is NX(m,1);
if its value is zero or AMISS(1) then the records with X(i,m,1)
and the Primary Variable values are omitted.
NAUXC is the number of Auxiliary Variables recorded
as character strings, which follow the real-valued Auxiliary
Variables and have lengths LENA(a), a=NAUXV-NAUXC+1,NAUXV.
Therefore, AMISS(a), a=NAUXV-NAUXC+1,NAUXV are also character
strings of length LENA(a).
NLHEAD 2160
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(1)
LENX(2)
[ XNAME(s) ] s=1,2
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NAUXV ........................ first auxiliary variable is NX(m,1)
NAUXC
[ ASCAL(a), a=1,NAUXV-NAUXC ]
[ AMISS(a), a=1,NAUXV-NAUXC ] ...................these are real
[ LENA(a), a=NAUXV-NAUXC+1,NAUXV ]
[ AMISS(a) ] a=NAUXV-NAUXC+1,NAUXV ..........these are strings
[ ANAME(a) ] a=1,NAUXV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
X(m,2) .......................................character string
[ NX(m,1) ( A(m,a), a=2,NAUXV-NAUXC ) ]
[ A(m,a) ] a=NAUXV-NAUXC+1,NAUXV ..............character strings
[ X(i,m,1) ( V(i,m,n), n=1,NV ) ] i=1,NX(m,1)
5.7 FFI = 2310
Two real Independent Variables (NIV=2); one unbounded,
one bounded with its number of constant increment values, base value
and increment defined in the Auxiliary Variable list.
Primary Variables are real.
Auxiliary Variables are real; the first three values are NX(m,1),
X(1,m,1) and DX(m,1), which define the bounded Independent
Variable values for the m-th Independent Variable Mark to
be X(i,m,1) = X(1,m,1) + (i-1) * DX(m,1) for i=1,NX(m,1).
If NX(m,1)=AMISS(1) or NX(m,1)=0 then the implication
is that the records containing values of the primary variables are
omitted, and the next record contains the succeeding Independent Variable
Mark and Auxiliary Variable values.
For each Primary Variable is a record of its values at the
bounded Independent Variable values.
NLHEAD 2310
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(2)
[ XNAME(s) ] s=1,2
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NAUXV ............first 3 auxil. var. are NX(m,1),X(1,m,1),DX(m,1)
[ ASCAL(a), a=1,NAUXV ]
[ AMISS(a), a=1,NAUXV ]
[ ANAME(a) ] a=1,NAUXV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
[ X(m,2) NX(m,1) X(1,m,1) DX(m,1) ( A(m,a), a=4,NAUXV ) ]
[ V(i,m,n), i=1,NX(m,1) ] n=1,NV
5.8 FFI = 3010
Three real Independent Variables (NIV=3); one unbounded, two
bounded with constant values defined in the file header.
Primary Variables are real.
Auxiliary Variables are real.
The Independent Variable Marks and Auxiliary Variable values
are in the same record.
For each Primary Variable and value of the second Independent
Variable, is a record of Primary Variable values at values
of the first Independent Variable.
NLHEAD 3010
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(1) DX(2) DX(3)
NX(1) NX(2)
NXDEF(1) NXDEF(2)
[ X(i,1), i=1,NXDEF(1) ]
[ X(j,2), j=1,NXDEF(2) ]
[ XNAME(s) ] s=1,3
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NAUXV
[ ASCAL(a), a=1,NAUXV ]
[ AMISS(a), a=1,NAUXV ]
[ ANAME(a) ] a=1,NAUXV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
[ X(m,3) ( A(m,a), a=1,NAUXV ) ]
[ V(i,j,m,n), i=1,NX(1) ] j=1,NX(2) n=1,NV
5.9 FFI = 4010
Four real Independent Variables (NIV=4); one unbounded, three
bounded with constant values defined in the file header.
Primary Variables are real.
Auxiliary Variables are real.
The Independent Variable Marks and Auxiliary Variables are
in the same record.
For each Primary Variable and value of the third and second
Independent Variables, is a record of Primary Variable
values at values of the first Independent Variable.
NLHEAD 4010
ONAME
ORG
SNAME
MNAME
IVOL NVOL
DATE RDATE
DX(1) DX(2) DX(3) DX(4)
NX(1) NX(2) NX(3)
NXDEF(1) NXDEF(2) NXDEF(3)
[ X(i,1), i=1,NXDEF(1) ]
[ X(j,2), j=1,NXDEF(2) ]
[ X(k,3), k=1,NXDEF(3) ]
[ XNAME(s) ] s=1,4
NV
[ VSCAL(n), n=1,NV ]
[ VMISS(n), n=1,NV ]
[ VNAME(n) ] n=1,NV
NAUXV
[ ASCAL(a), a=1,NAUXV ]
[ AMISS(a), a=1,NAUXV ]
[ ANAME(a) ] a=1,NAUXV
NSCOML
[ SCOM(k) ] k=1,NSCOML
NNCOML
[ NCOM(k) ] k=1,NNCOML
[ X(m,4) ( A(m,a), a=1,NAUXV ) ]
[ V(i,j,k,m,n), i=1,NX(1) ] j=1,NX(2) k=1,NX(3) n=1,NV
5.10 Summary of data record formats
- FFI=1001:
- [ X(m,1) ( V(m,n), n=1,NV ) ]
- FFI=1010:
- [ X(m,1) ( A(m,a), a=1,NAUXV ) ]
[ V(m,n), n=1,NV ]
- FFI=1020:
- [ X(m,1) ( A(m,a), a=1,NAUXV ) ]
[ V(i,n), i=1+(m-1)*NVPM(1),m*NVPM(1) ] n=1,NV
- FFI=2010:
- [ X(m,2) ( A(m,a), a=1,NAUXV ) ]
[ V(i,m,n), i=1,NX(1) ] n=1,NV
- FFI=2110:
- [ X(m,2) NX(m,1) ( A(m,a), a=2,NAUXV ) ]
[ X(i,m,1) ( V(i,m,n), n=1,NV ) ] i=1,NX(m,1)
- FFI=2160:
- X(m,2) ...................................... string
[ NX(m,1) ( A(m,a), a=2,NAUXV-NAUXC ) ]
[ A(m,a) ] a=NAUXV-NAUXC+1,NAUXV ............ strings
[ X(i,m,1) ( V(i,m,n), n=1,NV ) ] i=1,NX(m,1)
- FFI=2310:
- [ X(m,2) NX(m,1) X(1,m,1) DX(m,1) (A(m,a),a=4,NAUXV) ]
[ V(i,m,n), i=1,NX(m,1) ] n=1,NV
- FFI=3010:
- [ X(m,3) ( A(m,a), a=1,NAUXV ) ]
[ V(i,j,m,n), i=1,NX(1) ] j=1,NX(2) n=1,NV
- FFI=4010:
- [ X(m,4) ( A(m,a), a=1,NAUXV ) ]
[ V(i,j,k,m,n), i=1,NX(1) ] j=1,NX(2) k=1,NX(3) n=1,NV
6
Version 2 Format Extensions
This Section describes some extensions to the original ASCII exchange
file formats which were defined in the preceding Sections. These extensions
do add a layer of complexity to exchange files, and to this document
too, but those are balanced by the potential benefits:
- To make the definitions of the file header variables (ONAME,
ORG, SNAME, MNAME, XNAME, ANAME
and VNAME) more specific, and thus help reduce the problems
of multiple definitions for the same parameter, and of automatically
identifying geolocation, geophysical and special purpose parameters.
- To define conventions for using Normal Comment lines to specify
values which were not included in the Version 1.x formats. This opens
up the possibility of defining a variety of metadata in ways which
both humans and computer programs can find and use those data.
The extensions patch some inadequacies of the original exchange file
formats and provide additional information which can be used to facilitate
automatic processing of data, including the translation to and from
other archive formats without significant loss of information. The
extensions are backward-compatible with the original formats, so computer
programs designed to read the original formats can also read files
which incorporate the extensions, even if they ignore the additional
information provided by the extensions.
Instead of striving to define each archived parameter in all conceivable
detail, the primary goal is to provide a relatively simple way to
categorize each type of geolocation, geophysical and platform-specific
parameter, by first uniquely identifying each of those parameters,
and then linking them to the appropriate people, instrument/model,
measurement platform and location. Those basic relationships can be
used to build more detailed relationships, and to guide computer programs
through preliminary analyses of those parameters.
The format extensions consist of redefining the way metadata are recorded
in the character string variables in the file header. This is done
by dividing the value of each variable into fields and using each
field to store a particular bit of information. In many cases the
allowable values of a field are selected from a predefined list of
options maintained by the archivist.
Obviously, those lists must grow, so for this type of system to be
useful the lists must be actively maintained. Therefore, archive users
are encouraged to notify the archivist of any additions or corrections
they think should be made to the lists.
The vertical bar character,
|, is used as the field delimiter,
and each field value can include leading and trailing blank spaces
which are insignificant and can be removed without altering the field
value. However, after removing any leading or trailing blanks, the
remainder of any non-numeric field value is case-sensitive and space-sensitive.
Some field values are optional and can be blank or null (e.g.,
||).
Values of character string variables in exchange files are confined
to a single line, so to facilitate the documentation of the format
extensions, the ampersand character, &, is used to indicate continued
lines. This is only a figment of the documentation; ampersand characters
have no special meaning in exchange files. Likewise, ellipsis,
...,
are used in this document to indicate possibly omitted information.
The way to signal that an exchange file is using the Version 2 format
extensions is to use the following two metadata declarations as the
first two
Normal Comment lines:
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 21601
The details of the metadata declarations are described in Section
6.6, but for now it is sufficient to know that the presence
of those two lines implies that:
- the format extensions described in this Section apply;
- the value of NIVM (21601 in this example) is the
dimension of the unbounded Independent Variable (for all formats
except FFI=1020).
- additional metadata declarations may follow those two lines, and free-form
comments may follow the last metadata declaration.
If the first two
Normal Comment lines are not metadata declarations
for
format version and
NIVM then the original Version
1.x format, without the extensions, is assumed. Since the file header
can be read by computer programs which were designed to read the original
formats, one method for correctly interpreting all exchange files
is to first read the file header, and then check the first two
Normal
Comment lines for the required metadata declarations, and then based
on that test decide how to interpret the file header and data records.
ONAME provides the names of the Principal Investigators (PI)
and/or the Data Originators (DO) associated with the dataset, and
must include at least one complete name. The PI is the person who
is officially responsible for producing the data within the file.
If there is more than one PI (Co-PIs) then the names of all PIs should
be included in
ONAME. Some datasets may not have an associated
PI, so in those cases use one or more DO names. If the desired list
of names will not fit in the
ONAME line then use the
ONAME_add
metadata declaration, Section
6.6.4, to record additional
DO names.
A DO is a person involved in the data reduction and the generation
of the exchange file. If the PI also performed those tasks then there
is no need to include DO names.
Each name consists of two parts: the family name(s) and the given
name(s). Record each name as you would want it to appear in a name
database. The PI names are listed first, followed by the DO names.
ONAME always contains
2*(nPI+nDO)+2 fields, and
has the form:
nPI | nDO | PIfname | PIgname | ... | DOfname | DOgname | ...
- nPI
- is an integer value, zero or greater, specifying the
number of PI names (family/given name pairs) appearing in the ONAME
line.
- nDO
- is an integer value, zero or greater, specifying the
number of DO names (family/given name pairs) appearing in the ONAME
line.
- PIfname
- is a PI's family name(s), sometimes called a last
name.
- PIgname
- is a PI's given names, which include first name,
middle names, or initials.
- DOfname
- is a DO's family name(s).
- DOgname
- is a DO's given names.
- Example:
- 0 | 1 | Gaines | Steven E.
ORG gives the contact information for the primary contact:
the person to contact if someone has questions about the file. The
ORG_add metadata declaration, Section
6.6.4, can
be used to record additional contact information for other entries
in the
ONAME line.
ORG always contains four fields;
its format is:
NameNo | Affiliation | Email | (Extra)
- NameNo
- is the number of the name in ONAME to which
ORG applies. For example, if ONAME contains two
names and NameNo=2, then the information in ORG
pertains to the second name in ONAME, which occupies the
fifth and sixth fields in ONAME.
- Affiliation
- is the short name of the primary contact's
affiliation, selected from org_tab, described below. The
main purpose for including an affiliation is to help locate the person
if their email address becomes obsolete, so the organization at which
the contact works is often the appropriate choice for Affiliation,
even if it is not the contact's employer.
- Email
- is the contact's email address.
- Extra
- is an optional character string (can be blank or
null) which can be used to include telephone numbers, postal address
and additional Email addresses.
- Example:
- 1 | NASA ARC | gaines@cloud1.arc.nasa.gov |Tel:1-650-604-4546
6.2.1
Organizations
The value for
Affiliation in the
ORG variable is
selected from the first column of the
org_tab table, which
is maintained at
http://espoarchive.nasa.gov/archive/docs/org_tab.html.
An abridged version of
org_tab is included here for illustration.
Org | Organization Name |
|
DLR | Deutsches Zentrum fuer Luft- und Raumfahrt |
DU | University of Denver |
HU | Harvard University |
NASA ARC | NASA Ames Research Center |
NASA GSFC | NASA Goddard Space Flight Center |
NASA JPL | NASA Jet Propulsion Laboratory |
NASA LaRC | NASA Langley Research Center |
NCAR | National Center for Atmospheric Research |
NOAA AL | NOAA Aeronomy Laboratory |
NOAA CMDL | NOAA Climate Monitoring and Diagnostics Laboratory |
SNAME specifies, by measurement platform and instrument,
the sources of the data within the file. These specifications are
referenced by the parameter descriptions, Section
6.5,
to indicate both the source of the parameter and the location where
the parameter applies, so every instrument/platform referenced by
the parameter descriptions must be included in
SNAME. Use
the
SNAME_add metadata declaration, Section
6.6.4,
to specify data sources which will not fit in the
SNAME line.
SNAME always contains
2*nInst+2 fields, and has
the form:
nInst | Plat | Inst | Plat | Inst | ... | (Extra)
- nInst
- is the number of Plat|Inst pairs contained
in the SNAME line; must be greater than zero.
- Plat
- specifies the measurement platform from which data
were obtained, selected from plat_tab, described below.
If model results are being specified then use model as the
value for Plat.
- Inst
- specifies the instrument, or model, used to gather
or generate the data. Its value is selected from the first column
of inst_tab, described below.
- Extra
- is an optional descriptor (can be blank or null).
- Example:
- 3|WB-57 926|FCAS II|WB-57 926|N-MASS|WB-57 926|MMS|Combined aerosol data
The value for
Plat is selected from the first column of
plat_tab,
which is maintained at
http://espoarchive.nasa.gov/archive/docs/plat_tab.html.
An abridged version of
plat_tab is included here for illustration.
Plat | Platform Description |
Aura | Aura satellite |
balloon | Gondola balloon |
DC-8 717 | DC-8 aircraft, NASA ARC 717 |
DC-8 817 | DC-8 aircraft, NASA DFRC 817 |
ER-2 706 | ER-2 aircraft, NASA ARC 706 |
ground | Ground station, fixed location |
model | Mathematical model |
sonde | Small balloon, expendable instrument package |
WB-57 926 | WB-57 aircraft, NASA JSC 926 |
6.3.2
Instruments
The value for
Inst is selected from the first column of
inst_tab,
which is maintained at
http://espoarchive.nasa.gov/archive/docs/inst_tab.html.
An abridged version of
inst_tab is presented here.
Inst | Instrument Name |
|
ALIAS | Aircraft Laser Infrared Absorption Spectrometer |
DADS | Data Acquisition and Display System |
DIAL | Differential Absorption Lidar |
FCAS II | Focused Cavity Aerosol Spectrometer II |
GSFCAM | NASA GSFC Data Assimilation Model |
GSFCTM | NASA GSFC Trajectory Model |
HUCO2 | HU High-Altitude Fast-Response CO2 Analyzer |
HUTW | HU Total Water Instrument |
HUWV | HU Water Vapor Instrument |
ICATS | Information Collection and Transmission System |
LAH | Lyman Alpha Hygrometers |
MkIV | Mark IV Interferometer |
MMS | Meteorological Measurement System |
MTP | Microwave Temperature Profiler |
NavRec | Platform navigation recording system |
N-MASS | Nucleation-Mode Aerosol Size Spectrometer |
O3sonde | Ozonesonde instrument package |
raob | Radiosonde instrument package |
MNAME specifies the official short name for the mission which
the data is supporting. It always includes two fields, and has the
form:
Mshort | (Extra)
- Mshort
- is the official short name for the mission which
the data is supporting. Its value will be decided upon and communicated
to participants prior to the start of the mission.
- Extra
- is an optional descriptor (can be blank or null).
- Example:
- SOLVE II | flight over Greenland
6.5
XNAME(s), ANAME(a), VNAME(n)
This one gets a little complicated because it packs a lot of information
into one line, and values for several of the fields are inter-dependent.
However, following the documentation trail for each field should reveal
how to construct these variable descriptions. If not then please ask
the archivist.
XNAME(s),
ANAME(a) and
VNAME(n) each represent
a line of text describing, respectively, a particular
Independent,
Auxiliary or
Primary Variable. If longer descriptions
for a particular parameter seem necessary then use the
note_*
metadata declarations in Sections
6.6 and
6.6.4
to provide more complete descriptions. All variable names/descriptions
require eight fields, and have the form:
Subject| Qualifier| Units| (Extra)| Class| Type| Source| Where
- Subject
- specifies the general subject of the parameter.
Its allowable values are determined by the value of Class.
- Qualifier
- further specifies a parameter by qualifying the
value of Subject. Its allowable values are also determined
by the value of Class.
- Units
- specifies the physical units of measure for the parameter
being described. If the parameter is a numeric Dependent Variable
(Auxiliary or Primary) then its recorded values are
multiplied by the appropriate scale factor (ASCAL or VSCAL)
to arrive at the specified units. The units for character string values
are set to NULL.
- Units = RecordedValue * SCAL
- Investigators are free to use any units they think are appropriate,
with the stipulation that the units of geolocation, geophysical and
platform-specific parameters (Class is gloc*,
gphy* or plat) must be convertible to Standard
Units by the method described in Section 6.6.2.
For those parameter classes, Subject and Qualifier
are selected from the various tables which are introduced in this
Section, and are associated with specific Standard Units. So if the
value of Units is not Standard Units then a conversion to
Standard Units must be provided in the Normal Comment metadata
declarations, Section 6.6.2.
- Extra
- is an optional description which can be used to further
specify the parameter. Its value can be blank or null.
- Class
- specifies the parameter class of each variable, and
its value determines the allowable values for Subject and
Qualifier. Class must have one of the following
values (this list may grow):
- gloc
- indicates a geolocation parameter. The Subject
and Qualifier values for the description of a geolocation
parameter are selected from the allowable values in the gloc_subj_tab
and gloc_qual_tab tables, described in Sections 6.5.1
and 6.5.2. There are basically four geolocation coordinates
(altitude, latitude, longitude and time), with several methods for
measuring each coordinate. The coordinate is selected from the Subject
column of gloc_subj_tab and the measurement method is selected
from gloc_qual_tab. Each exchange file must include at
least one geolocation parameter (usually time) which, through reference
to other measurements, can be related to the other coordinates (see
the description of Where, below).
- gloc_S_n
- indicates that the parameter is a geolocation
coordinate for the platform/instrument described by the n-th
Plat|Inst entry in SNAME. For example, a value of
gloc_S_1 indicates a geolocation coordinate for the first
Plat|Inst entry in SNAME, which occupies the second
and third fields in SNAME. This class is provided for those
situations where it is useful to distinguish between the location
of a measurement platform and the location of an observation. The
Subject and Qualifier values are selected in the
same way as with Class=gloc, although there is no requirement
for exchange files to include these platform geolocation parameters.
- gphy_air
- indicates a measurement or simulation of some
geophysical parameter in the atmosphere. The Subject and
Qualifier values for the description of a geophysical parameter
are selected from the allowable values in the gphy_subj_tab
and gphy_qual_tab tables, described in Sections 6.5.3
and 6.5.4. The value of Subject specifies
whether the parameter measures a bulk property or an ingredient of
the atmosphere; Qualifier specifies the measurement.
- gphy_sea
- indicates a measurement or simulation of some
geophysical parameter in the sea, and Subject and Qualifier
for this class are defined in the same way as for the gphy_air
class.
- plat
- indicates a platform-specific parameter, other than
its geolocation. For this class the value for Subject is
selected from the Plat column of plat_tab, Section
6.3.1, to indicate the measurement platform to which the
parameter refers. The value for Qualifier is selected from
the allowable values in plat_qual_tab table, described
in Section 6.5.5.
- anal
- indicates an analysis-specific parameter. Investigators
are free to choose values for Subject and Qualifier
for their analysis-specific parameters, but they should use the predefined
values from the various tables when feasible, or at least follow a
similar parameter description scheme. Analysis-specific parameters
include things like error estimates, special flag variables, sample
averaging times and correction factors.
- inst
- indicates an instrument-specific parameter, other
than its geolocation. For this class, the value for Subject
is selected from the first column of inst_tab, Section 6.3.2,
to indicate the instrument to which the parameter refers. Investigators
are free to choose a value for Qualifier. Instrument-specific
parameters include things like sample volume flow rate, laser pulse
rate, instrument temperature, etc.
- Type
- specifies the type of parameter, with its value selected
from the following list (which may grow):
- insitu
- indicates the parameter is an in situ sample
or measurement, or derived from primarily in situ measurements.
- remote
- indicates the parameter is a remotely sensed quantity,
or derived from primarily remotely sensed quantities.
- model
- indicates a modeled parameter, which includes climatological
statistics and UTC.
- user
- is a catch-all option to indicate a user-defined parameter
which is not described by any of the other options. This type includes
things like index counters and other analysis- and instrument-specific
parameters. Obviously, this is not an option for geolocation, geophysical
and platform-specific parameters because Subject and Qualifier
for those classes of parameters are selected from predefined lists.
- DLf_V_n
- indicates the parameter is a measurement detection
limit flag variable for the n-th Primary Variable,
V(X,n), with n having a value in the range n=1,NV.
This special type of parameter is used to indicate which values of
V(X,n) have been set to missing values because they were
below or above detection limits. A missing value indicates missing
or erroneous data, and the following reserved values flag the indicated
events:
0 = a valid value;
1 = value is below detection limit;
2 = value is above detection limit.
- Users can define additional flag values between 2 and the missing
value to indicate other events which cause missing data, like a calibration
period, large aircraft roll angle, etc. Additional flag values should
be defined in a note_V_n metadata declaration (Section
6.6.4).
- If the detection limits for V(X,n) are variable then an additional
Primary Variable with Type=DLv_V_n will be included
to specify the detection limits.
- If the detection limits for V(X,n) are constant then a Normal
Comment metadata declaration for LUDL_V_n is used to specify
the constant values for the lower and upper detection limits (see
Section 6.6.3).
- DLv_V_n
- indicates the parameter specifies the detection
limit values for the n-th Primary Variable, V(X,n).
A parameter of this type is always associated with a corresponding
flag parameter of Type=DLf_V_n, such that when the flag
parameter has a value of 1 then the value of this parameter
specifies the lower detection limit of V(X,n); and when the
flag parameter has a value of 2 then the value of this parameter
specifies the upper detection limit for V(X,n). Otherwise,
the value of this parameter is its missing value.
- The value of Units for this parameter must be the same as
the units of V(X,n), specified in VNAME(n).
- e_X_s
- indicates the parameter is an error estimate for
the s-th Independent Variable. The range of values
for s is s=1,NIV.
- e_A_a
- indicates the parameter is an error estimate for
the a-th Auxiliary Variable, where a can
have a value in the range a=1,NAUXV.
- e_V_n
- indicates the parameter is an error estimate for
the n-th Primary Variable, with n having
a value in the range n=1,NV.
- f_X_s
- indicates the parameter is a user-defined flag
variable pertaining to the s-th Independent Variable,
with the value of s in the range s=1,NIV.
- f_A_a
- indicates the parameter is a user-defined flag
variable pertaining to the a-th Auxiliary Variable,
with the value of a in the range a=1,NAUXV.
- f_V_n
- indicates the parameter is a user-defined flag
variable pertaining to the n-th Primary Variable,
with the value of n in the range n=1,NV.
- Source
- specifies the source(s) of the parameter by a list
of one or more space-separated options of the form S_n,
indicating the n-th Plat|Inst entry in SNAME
(see Section 6.3). For example, if the value of Source
is S_2 then the source is the second Plat|Inst
entry in SNAME, which occupies the fourth and fifth fields
in SNAME.
- Where
- specifies where, in time/space, this parameter applies.
A list of one to four space-separated options is used to designate
the data variables or data sources which provide geolocation coordinates
for this parameter. If this parameter is a geolocation coordinate
then use the list to indicate the remaining coordinates or sources
for those coordinates. If, instead of altitude, your analysis uses
pressure or potential temperature as a vertical coordinate then include
that in the list. Options are:
- A_n
- indicates the n-th Auxiliary Variable.
- V_n
- indicates the n-th Primary Variable.
- X_n
- indicates the n-th Independent Variable.
- S_n
- indicates the n-th Plat|Inst entry
in SNAME (as with Source). If some geolocation coordinates
for this parameter are not specified in the exchange file then use
this option to point to an instrument which provides the unspecified
coordinates (directly related, of course, to a coordinate which is
specified).
- Example1:
- altitude | geometric | m | GPS altitude of aircraft plus &
altitude from laser | gloc | remote | S_1 S_2 | X_2 A_8 A_9
- Example2:
- air | parcel number | 1 || anal | user | S_1 | X_2 V_1 V_2 V_3
- Example3:
- air | temperature | K || gphy_air | insitu | S_1 | X_1 S_1
- Example4:
- air | temperature error | K | 1-sigma uncertainty | &
anal | e_V_2 | S_1 | X_1 S_1
In the above examples, Example4 describes a parameter which gives
error estimates for the second
Primary Variable, indicated
by the
e_V_2 value for
Type.
6.5.1
Geolocation Subjects
For a geolocation parameter, i.e.,
Class=gloc or
Class=gloc_S_n,
the value of
Subject is selected from the
gloc_subj_tab
table and an appropriate
Qualifier is selected from the
gloc_qual_tab
table. Although atmospheric pressure and potential temperature are
often used as vertical coordinates, they are not classified as geolocation
parameters; they are instead classified as bulk properties of the
atmosphere. Barometric and geopotential altitudes are related to pressure,
and they are grouped as geolocation parameters. This classification
scheme was adopted mainly as a convenience.
The complete and current version of
gloc_subj_tab is maintained
at
http://espoarchive.nasa.gov/archive/docs/gloc_subj_tab.html.
Class | Subject | Notes |
|
gloc | altitude | Altitude is measured as height above mean sea level (MSL), although
there are various models for both MSL and the height above MSL. Negative
if below MSL. |
gloc | latitude | Latitude is measured as positive north of the Equator, negative south
of the Equator. Range: -90 to +90. |
gloc | longitude | Longitude is measured as east longitude; west longitude can be expressed
as negative numbers. Range is either 0 to 360, or -180 to +180. |
gloc | time | Time of an observation, or applicable time of an integrated measurement
or grab sample. |
gloc | launch time | Launch time of an aircraft or sounding platform (balloon, rocket,
dropsonde, etc.). |
gloc | sample start time | Start time of a grab sample or integrated measurement. Requires an
associated stop time. |
gloc | sample stop time | Stop time of a grab sample or integrated measurement. Requires an
associated start time. |
6.5.2
Geolocation Qualifiers
For a geolocation parameter, the value of
Qualifier is selected
from the
gloc_qual_tab table so that it will appropriately
qualify the value of
Subject selected from
gloc_subj_tab.
Examining both the Qualifier and Standard Units columns in
gloc_qual_tab
should make the appropriate selection unambiguous.
If the value of
Units used in the parameter description do
not match the Standard Units given in
gloc_qual_tab then
it is required to include the appropriate
Normal Comment metadata
declarations to define the conversion from
Units to Standard
Units, as described in Section
6.6.2.
The complete and current version of
gloc_qual_tab is maintained
at
http://espoarchive.nasa.gov/archive/docs/gloc_qual_tab.html.
Class | Qualifier | Standard Units | Notes |
|
gloc | barometric | m | A synonym for pressure altitude. Which Standard Atmosphere? |
gloc | geodetic | m | Surveyed or modeled using a geodetic Earth model (non-GPS). Which
model? |
gloc | geometric | m | Geometrically measured height above MSL (lidar, radar, yardstick,
...). |
gloc | geopotential | m | Geopotential meters, from hydrostatic integration. |
gloc | GPS | m | Global Positioning System (GPS) uses the WGS-84 Earth model. |
gloc | geodetic | deg | Surveyed or modeled using a (non-GPS) geodetic Earth model. Which
model? |
gloc | GPS | deg | Global Positioning System uses the WGS-84 Earth model. |
gloc | INS | deg | Inertial Navigation System (INS). |
gloc | spherical | deg | Spherical Earth model. Radius? |
gloc | seconds | s | Seconds since 00:00 UTC on day given by DATE (line 7). |
gloc | hours | h | Hours since 00:00 UTC on day given by DATE (line 7). |
gloc | days | d | Days since 00:00 UTC on day given by DATE (line 7). |
gloc | days since year0 | d | Days since 00:00 UTC on January 1 of year given in DATE (line 7). |
6.5.3
Geophysical Subjects
For a geophysical parameter, i.e., in the
gphy_air or
gphy_sea
classes, the value of
Subject is selected from the
gphy_subj_tab
table and an appropriate
Qualifier is selected from the
gphy_qual_tab
table. Geophysical parameters are basically divided into measures
of the bulk properties of the medium and measures of the ingredients
of the medium.
The complete and current version of
gphy_subj_tab is maintained
at
http://espoarchive.nasa.gov/archive/docs/gphy_subj_tab.html;
an abridged version of that table is presented here for illustration.
Class | Subject | Notes |
|
gphy | air | Bulk property of the atmosphere |
gphy | sea | Bulk property of the sea/ocean |
gphy | cloud | Atmospheric cloud property |
gphy | aerosol | Solid or liquid particles suspended in the atmosphere |
gphy | sulfate aerosol | |
gphy | soot | |
gphy | CH4 | Methane molecules |
gphy | ClO | Chlorine monoxide molecules |
gphy | ClNO3 | Chlorine nitrate molecules |
gphy | CO | Carbon monoxide molecules |
gphy | CO2 | Carbon dioxide molecules |
gphy | H2O | Water molecules |
gphy | H2O ice | Water, solid phase |
gphy | H2O liquid | Water, liquid phase |
gphy | H2O vapor | Water, vapor phase |
gphy | H2SO4 | Sulfuric acid |
gphy | HCl | Hydrogen chloride molecules |
gphy | HF | Hydrogen fluoride molecules |
gphy | HNO3 | Nitric acid |
gphy | N2O | Nitrous oxide molecules |
gphy | NO | Nitric oxide molecules |
gphy | NO2 | Nitrogen dioxide molecules |
gphy | O3 | Ozone molecules. |
gphy | SO2 | Sulfur dioxide molecules |
6.5.4
Geophysical Qualifiers
For a geophysical parameter, the value of
Qualifier is selected
from the
gphy_qual_tab table so that it will appropriately
qualify the value of
Subject selected from
gphy_subj_tab.
Examining both the Qualifier and Standard Units columns in
gphy_qual_tab
should make the appropriate selection unambiguous.
The Notes column in
gphy_qual_tab sometimes uses the terms
substance and
mixture to help clarify the parameter
descriptions. The term
mixture refers to the medium in which
the parameter applies (air or sea, obtained from the value of
Class).
The term
substance refers to the thing defined by the value
of
Subject, which can be either the mixture itself or an
ingredient of the mixture.
If the value of
Units used in the parameter description do
not match the Standard Units given in
gphy_qual_tab then
it is required to include the appropriate
Normal Comment metadata
declarations to define the conversion from
Units to Standard
Units, as described in Section
6.6.2.
The complete and current version of
gphy_qual_tab is maintained
at
http://espoarchive.nasa.gov/archive/docs/gphy_qual_tab.html.
Class | Qualifier | Standard Units | Notes |
|
gphy | pressure | Pa | |
gphy | partial pressure | Pa | Partial pressure of a gaseous ingredient. |
gphy | saturation vapor pressure | Pa | Over water? Over ice? |
gphy | relative humidity | 1 | Ratio of the actual water vapor pressure to the saturation vapor pressure
(Pa Pa-1). |
gphy | temperature | K | |
gphy | dew-point temperature | K | |
gphy | dew-point depression | K | Difference between temperature and dew-point temperature. |
gphy | frost-point temperature | K | |
gphy | virtual temperature | K | |
gphy | potential temperature | K | |
gphy | brightness temperature | K | Radiant energy intensity of a particular wave band, expressed as temperature. |
gphy | wind direction | deg | Direction from which the horizontal wind blows, reckoned clockwise
from true north. |
gphy | wind speed | m s-1 | Magnitude of horizontal wind component. |
gphy | eastward wind | m s-1 | Magnitude of east-west wind component; positive toward east. |
gphy | northward wind | m s-1 | Magnitude of north-south wind component; positive toward north. |
gphy | vertical wind | m s-1 | Magnitude of vertical wind component; positive upward. |
gphy | potential vorticity | K m2 kg-1 s-1 | |
gphy | mass density | kg m-3 | Mass of an ingredient per unit volume of that ingredient. |
gphy | mass concentration | kg m-3 | Mass of a substance per unit volume of the mixture. |
gphy | number concentration | m-3 | The number of particles or molecules of a substance per unit volume
of the mixture. |
gphy | column number | m-2 | Number concentration integrated over a line-of-sight. Zenith? Nadir?
Slant? |
gphy | surface area concentration | m-1 | Total particle surface area of a substance per unit volume of the
mixture (m2 m-3). |
gphy | volume concentration | 1 | Total particle volume of a substance per unit volume of the mixture
(m3 m-3). |
gphy | mass mixing ratio | 1 | Ratio of the mass concentration of an ingredient to the mass concentration
of all other ingredients of the mixture. |
gphy | mass fraction | 1 | Ratio of the mass concentration of a substance to the mass concentration
of the mixture. Synonym for specific humidity if the ingredient is
water vapor and the mixture is air. |
gphy | aerosol mass fraction | 1 | Ratio of the mass concentration of a substance to the mass concentration
of all aerosols. |
gphy | volume mixing ratio | 1 | Ratio of the number of moles of an ingredient to the total number
of moles of all other ingredients of the mixture (mol mol-1). |
gphy | mole fraction | 1 | Ratio of the number of moles of a substance to the total number of
moles in the mixture (mol mol-1). |
gphy | specific number | kg-1 | The number of particles or molecules of a substance per unit mass
of the mixture. |
gphy | diameter | m | |
|
6.5.5
Platform Qualifiers
For a platform-specific parameter,
Class=plat, the value
of
Qualifier is selected from the
plat_qual_tab
table; the value of
Subject is selected from the Plat column
of the
plat_tab table, to indicate the measurement platform
to which the parameter refers. Examining both the Qualifier and Standard
Units columns in
plat_qual_tab should make the appropriate
selection unambiguous.
If the value of
Units used in the parameter description do
not match the Standard Units given in
plat_qual_tab then
it is required to include the appropriate
Normal Comment metadata
declarations to define the conversion from
Units to Standard
Units, as described in Section
6.6.2.
The complete and current version of
plat_qual_tab is maintained
at
http://espoarchive.nasa.gov/archive/docs/plat_qual_tab.html.
Class | Qualifier | Standard Units | Notes |
|
plat | ground speed | m s-1 | Speed relative to the ground. |
plat | eastward speed | m s-1 | Magnitude of east-west ground speed component; positive toward east. |
plat | northward speed | m s-1 | Magnitude of north-south ground speed component; positive toward north. |
plat | vertical speed | m s-1 | Positive upward, negative downward. |
plat | true air speed | m s-1 | Speed relative to the air. |
plat | Mach number | 1 | Ratio of the true air speed to the speed of sound. |
plat | height above Earth | m | From radar or lidar height (geometric). |
plat | ground track angle | deg | Reckoned clockwise from true north. |
plat | pitch angle | deg | Nose up is positive. |
plat | roll angle | deg | Right wing down is positive. |
plat | true heading | deg | Reckoned clockwise from true north. |
6.6
Normal Comment Lines
Any information which can be expressed with printable ASCII characters
can be included in the
Normal Comment lines. It is, however,
often useful to have some of that information recorded in ways which
both humans and computer programs can readily extract it. To help
with that task, the format extensions include conventions for recording
arbitrary numeric arrays and string arrays in the
Normal Comment
lines. Specially named numeric arrays are used to signal that the
file employs the extended format. In this subsection we describe those
conventions, and also offer a method for standardizing the way certain
parameters are recorded in the
Normal Comment lines.
There are two types of
Normal Comment metadata declarations,
and each can span more than one line. In general, fields in these
declarations are delimited by the field delimiter,
|, although
the beginning and end of a line can also delimit the beginning or
end of most fields; the exception being the field containing numeric
array elements.
#MD | NA | Name | N_elements | val1 val2 val3 ... valN
#MD | SA | Name | N_elements | string1 | string2 | ... | stringN
- #MD
- indicates the start of a metadata declaration, and
must be the first non-blank characters on a line.
- NA
- indicates the declaration is for a numeric array. The
last field in this type of declaration contains N_elements
space-separated numeric values (real numbers), which can span multiple
lines, and as such is treated as a special type of field. The idea
is to read as many lines as necessary to gather the indicated number
of values.
- SA
- indicates the declaration is for an array of character
string values. There is a separate field for each array element (character
string), and there can be several elements on the same line or one
element on a line, but no element can span more than one line. Each
element is terminated by either a field delimiter, |, or
the end of a line, and starts after either a preceding field delimiter
or the beginning of a line.
- Name
- specifies the name of the parameter being defined
in the metadata declaration. The required metadata, and commonly used
metadata, are given specific names and listed in NA_tab
and SA_tab, below, to help standardize their usage. Customized
values for Name are also allowed, but investigators are encouraged
to use the names in those tables when applicable.
- N_elements
- is an integer value which specifies the number
of array elements in the declaration. Its value must be greater than
zero.
- Example1:
- #MD | NA | SUscale_V | 8 | 0.3048 1 0.5144 0.5144
1 1 1000 0.01
- Example2:
- #MD | NA | LUDL_V_3 | 2 | -500 500
- Example3:
- #MD | SA | station name | 1 | Fairbanks, Alaska
- Example4:
- #MD | SA | note_X_1 | 3
The altitude of an observation, reckoned by adding the
GPS altitude of the instrument and the laser height of the
observation above the instrument
- Example5:
- #MD | SA | SU_V | 4 | m | K | m s-1 | m s-1
6.6.1 Signal Version 2 extensions
When a file employs the format extensions, at least two metadata declarations
are required to specify
format version and
NIVM.
Those two declarations must occupy the first two
Normal Comment
lines, and look like:
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 170
The first of those declarations specifies that Version 2 format extensions
are employed in the file, and the second specifies that there are
170 (for example) Independent Variable Marks recorded in
the file. For all formats except FFI=1020, the value of NIVM is also
the dimension of the unbounded
Independent Variable. Other
metadata declarations can follow those first two, and free-form comments
can follow the last metadata declaration. Without those first two
declarations the file is assumed to be written in the Version 1.x
formats, without the extensions.
6.6.2
Conversion to Standard Units
There are several other metadata declarations which may be required.
As explained in Section
6.5, if a parameter described
in
XNAME,
ANAME or
VNAME is in the
gloc*,
gphy* or
plat class (i.e., a geolocation, geophysical
or platform-specific parameter) and its specified units are not Standard
Units from the appropriate Qualifier table, then three additional
declarations are required to specify its conversion to Standard Units.
To illustrate, suppose there are three
Primary Variables (
NV=3)
with the following
VNAME descriptions:
altitude | barometric | feet || gloc | insitu | S_2 | X_1 S_2
air | temperature | K || gphy_air | insitu | S_1 | X_1 V_1 S_2
air | temperature error | K || anal | e_V_2 | S_1 | X_1 V_1 S_2
Since
altitude is a geolocation parameter and
feet
are not Standard Units, three additional metadata declarations are
required to convert all of the
Primary Variable units to Standard
Units:
#MD | NA | SUoffset_V | 3 | 0 0 0
#MD | NA | SUscale_V | 3 | 0.3048 1 1
#MD | SA | SU_V | 3 | m | K | NULL
The third
Primary Variable (temperature error) is an analysis-specific
parameter and, as such, does not require a valid conversion to Standard
Units. The same would be true if it were an instrument-specific parameter;
in both cases a valid conversion to Standard Units is not required.
However, since the metadata declarations require entries for all
Primary
Variables, there must at least be place-holders in the declarations
for parameters which need not, and maybe cannot, be converted to Standard
Units. The above example illustrates the convention for handling such
cases, which is an offset of
0, a scale factor of
1
and
NULL as the Standard Units.
The conversion from the units specified in the variable description
to Standard Units is:
SU = (Units * SUscale) + SUoffset
That conversion is for both
Independent and
Dependent
Variables. However, recall that there is also a scale factor (
ASCAL
or
VSCAL) associated with each numeric
Dependent Variable
which multiplies the values recorded in the data records to yield
the specified
Units. That additional conversion for
Dependent
Variables is symbolically represented as:
Units = RecordedValue * SCAL
where
RecordedValue is a value recorded in the data records
and
SCAL is the appropriate scale factor obtained from the
file header (
ASCAL or
VSCAL).
The aforementioned example indicates the Standard Units conversion
parameters for
Primary Variables; similar parameters for
Independent
and
Auxiliary Variables are listed in
NA_tab and
SA_tab.
6.6.3
Normal Comment Numeric Data
This table lists several standardized names to use in numeric array
metadata declarations. The complete and current version of
NA_tab
is maintained at
http://espoarchive.nasa.gov/archive/docs/NA_tab.html.
NA Name | Description |
|
format version | One element specifying the format version. A value of 2 indicates
Version 2 format extensions. Must be the first metadata declaration |
LUDL_V_n | Two elements which specify the constant lower and upper detection
limits for the n-th Primary Variable, V(X,n), where n can assume a
value in the range n=1,NV. Same units as V(X,n). |
NIVM | One element specifying the number of Independent Variable Marks, which
is also the dimension of the unbounded Independent Variable (for all
formats except FFI=1020). Must be the second metadata declaration. |
SUoffset_A | NAUXV-NAUXC elements specifying the offsets to convert units of all
numeric Auxiliary Variables to Standard Units. |
SUoffset_V | NV elements specifying the offsets to convert units of all Primary
Variables to Standard Units. |
SUoffset_X | NIV elements specifying the offset to convert units of all Independent
Variables to Standard Units. |
SUscale_A | NAUXV-NAUXC elements specifying the scale factors to convert units
of all numeric Auxiliary Variables to Standard Units. |
SUscale_V | NV elements specifying the scale factors to convert units of all Primary
Variables to Standard Units. |
SUscale_X | NIV elements specifying the scale factors to convert units of all
Independent Variables to Standard Units. |
6.6.4
Normal Comment String Data
This table lists several standardized names to use in string array
metadata declarations. The complete and current version of
SA_tab
is maintained at
http://espoarchive.nasa.gov/archive/docs/SA_tab.html.
SA Name | Description |
|
note_A_a | Note pertaining to a-th Auxiliary Variable; a=1,NAUXV. For more complete
descriptions of a parameter and of its measurement and error characteristics. |
note_V_n | Note pertaining to n-th Primary Variable; n=1,NV. For more complete
descriptions of a parameter and of its measurement and error characteristics. |
note_X_s | Note pertaining to s-th Independent Variable; s=1,NIV. For more complete
descriptions of a parameter and of its measurement and error characteristics. |
ONAME_add | An even-element array specifying family and given names of additional
contributors (DOs) to the exchange file, which will not fit in the
ONAME line. |
ORG_add | An array specifying additional contact information. There are 4 elements
for each additional person, which correspond to the 4 fields in the
ORG line. |
SNAME_add | An even-element array specifying additional Platform/Instrument data
sources, which will not fit in the SNAME line. These additional sources
are a continuation of those listed in SNAME and can also be referenced
from parameter descriptions. |
station name | One element specifying the name of a fixed station. |
SU_A | NAUXV-NAUXC elements specifying the Standard Units for all numeric
Auxiliary Variables. |
SU_V | NV elements specifying the Standard Units for all Primary Variables. |
SU_X | NIV elements specifying the Standard Units for all Independent Variables. |
6.7
Standard Units
The concept of Standard Units is used to facilitate automated calculations
involving geolocation, geophysical and platform-specific parameters.
The standardized names and units for those parameters are listed in
the various tables in Section
6.5. Investigators are
free to express those parameters in whichever units they prefer, but
if their choice of units is not Standard Units then they must also
provide the conversion from their units to Standard Units, as in Section
6.6.2. Thus, investigators can use their preferred
units, and those users who are so inclined can automate calculations
with the Standard Units or conversions of the Standard Units to some
other units. The alternative to such a scheme would be to list all
common choices for units in the tables, which would result in much
longer tables and require more decision-making to be built into computer
programs. The drawback of the Standard Units scheme is that most exchange
files will have to include metadata declarations to convert their
units to Standard Units because commonly used units like
mb,
hPa and
ppbv are not Standard Units.
Standard Units are SI units with one exception and several additions.
The exception is that Standard Units measure plane angles in degrees
(
deg) instead of radians. For reference, the following table
lists the elemental Standard Units, with the understanding that they
can be appropriately combined to yield the Standard Units listed as
options in the Qualifier tables in Section
6.5.
Quantity | Name | In Base Units | Standard Units |
|
Standard Units not required | | | NULL |
pure number, unitless | | | 1 |
length | meter | m | m |
mass | kilogram | kg | kg |
time | second | s | s |
thermodynamic temperature | kelvin | K | K |
amount of substance | mole | mol | mol |
electric current | ampere | A | A |
luminous intensity | candela | cd | cd |
pressure | pascal | m-1 kg s-2 | Pa |
energy | joule | m2 kg s-2 | J |
power | watt | m2 kg s-3 | W |
solid angle | steradian | m2 m-2 | sr |
plane angle | degree | | deg |
hour | hour | h | h |
day | day | d | d |
7
Format Examples
This Section provides two fictitious examples for each file format,
one without and one with the format extensions, ordered by increasing
file format index (FFI). For each example is a file header followed
by a sample of the data records. Numeric constants in the file headers
have been annotated with comments enclosed by curly braces,
{
}, which usually indicate the name of the variable used in the format
recipes in Section
5, and defined in Section
4.
The annotations are included here as references and need not appear
in exchange files. The data records in some of the examples have also
been annotated, but those are solely for illustration since annotations
should not appear in the data records of exchange files. Aside from
the annotations, each example tries to mimic what you would see if
you viewed the sample exchange file with a text editor.
Again, as in Section
6, the ampersand character,
&,
is used to indicate continued lines, and ellipsis,
...,
are used to indicate possibly omitted information. This is just to
facilitate documenting the formats; those characters have no special
meaning in exchange files.
7.1 FFI=1001
22 1001 {NLHEAD FFI}
Mertz, Fred U.
NASA ARC (fum@nasa.gov)
Wind data from NASA ER-2 Meteorological Measurement System (MMS)
TOP /ferry flight to Tahiti
1 1 {IVOL NVOL}
1991 1 16 1991 1 16 {DATE RDATE}
0 {DX(1)}
Seconds since 00Z (s)
3 {NV}
0.1 0.1 0.1 {VSCAL}
9999 9999 9999 {VMISS}
horizontal wind speed (m s-1)
horizontal wind direction (deg); true direction from which it blows.
vertical wind (m s-1) + up
1 {NSCOML}
Pilot reported CAT between the times 50300-50400.
4 {NNCOML}
Preliminary wind data
1Hz desampled from 5Hz
OMEGA used for calc = 0.06280 RAD/SEC
UTs Spd Dir w
30446.9 305 2592 22
30447.9 304 2596 22
30448.9 305 2601 9999
30449.9 306 2603 9999
30450.9 307 2606 25
30451.8 307 2607 27
30452.8 309 2610 29
30453.8 310 2610 29
30454.8 312 2621 32
...
24 1001 {NLHEAD FFI}
1 | 0 | Mertz | Fred U.
1 | NASA ARC | fum@nasa.gov |
1 | ER-2 706 | MMS | Wind data
TOP | Tahiti Ozone Project, ferry flight to Tahiti
1 1 {IVOL NVOL}
1991 1 16 1991 1 16 {DATE RDATE}
0 {DX(1)}
time | seconds | s || gloc | model | S_1 | S_1
3 {NV}
0.1 0.1 0.1 {VSCAL(n)}
9999 9999 9999 {VMISS(n)}
air | wind speed | m s-1 || gphy_air | insitu | S_1 | X_1 S_1
air | wind direction | deg || gphy_air | insitu | S_1 | X_1 S_1
air | vertical wind | m s-1 || gphy_air | insitu | S_1 | X_1 S_1
1 {NSCOML}
Pilot reported CAT between the times 50300-50400.
6 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 21609
Preliminary wind data
1Hz desampled from 5Hz
OMEGA used for calc = 0.06280 RAD/SEC
UTs Spd Dir w
30446.9 305 2592 22
30447.9 304 2596 22
30448.9 305 2601 9999
30449.9 306 2603 9999
30450.9 307 2606 25
30451.8 307 2607 27
30452.8 309 2610 29
30453.8 310 2610 29
30454.8 312 2621 32
...
7.2 FFI=1010
38 1010 {NLHEAD FFI}
Mertz, Fred; Mertz, Ethel; Ricardo, Lucy B.
NASA JPL; E.Mertz: elm@nasa.gov
DC-8 Mark IV Interferometer
TOP
1 1 {IVOL NVOL}
1991 1 16 1991 2 15 {DATE RDATE}
0 {DX(1)}
UTC fractional day number of year given in DATE (d)
8 {NV}
1.0E+17 1.0E+14 1.0E+13 1.0E+14 1.0E+14 1.0E+13 1.0E+13 1.0E+18
9999 9999 9999 9999 9999 9999 9999 9999 {VMISS}
O3 column density (molecules cm-2)
NO column density (molecules cm-2)
NO2 column density (molecules cm-2)
HNO3 column density (molecules cm-2)
ClNO3 column density (molecules cm-2)
HCl column density (molecules cm-2)
HF column density (molecules cm2)
H2O column density (molecules cm-2)
10 {NAUXV}
1 1 1 1 1 1 1 1 1 1 {ASCAL}
99 99 99 99 99.9 999.9 999.9 999 9999 999 {AMISS}
UTC Month (mon)
UTC Day (d)
UTC Hour (h)
UTC Minute (min)
Latitude (degrees)
Longitude (degrees)
Solar zenith angle (degrees) reckoned from DC-8
Air temperature (Celsius)
Static pressure (millibars)
Potential temperature (Kelvin)
0 {NSCOML}
3 {NNCOML}
NOTE 1: Geolocation data taken from DADS and appropriately averaged.
NOTE 2: All these column values will change when analyses are
repeated.
16.021 1 16 0 30 -5.9 -125.0 88.4 -56 237 328
80 24 75 142 12 240 72 47
16.038 1 16 0 55 -6.0 -127.1 88.5 -57 237 328
70 19 82 121 12 243 72 56
16.158 1 16 3 48 -6.4 -137.7 88.9 -57 237 327
71 16 78 118 10 237 56 49
...
50 1010 {NLHEAD FFI}
2 | 1 | Mertz | Fred | Mertz | Ethel | Ricardo | Lucy B.
2 | NASA JPL | elm@nasa.gov |
2 | DC-8 717 | MkIV | DC-8 717 | DADS | DC-8 Mark IV Interferometer
TOP |
1 1 {IVOL NVOL}
1991 1 16 1991 2 15 {DATE RDATE}
0 {DX(1)}
time|days since year0|DayOfYear|=1 at 1 Jan 00Z|gloc|model|S_1|A_5 A_6 A_9
8 {NV}
1.0E+17 1.0E+14 1.0E+13 1.0E+14 1.0E+14 1.0E+13 1.0E+13 1.0E+18
9999 9999 9999 9999 9999 9999 9999 9999 {VMISS}
O3|column number|molecules cm-2|zenith|gphy_air|remote|S_1 S_2|X_1 A_5 A_6 A_9
NO|column number|molecules cm-2|zenith|gphy_air|remote|S_1 S_2|X_1 A_5 A_6 A_9
NO2|column number|molecules cm-2|zenith|gphy_air|remote|S_1 S_2|X_1 A_5 A_6 A_9
HNO3|column number|molecules cm-2|zenith|gphy_air|remote|S_1 S_2|X_1 A_5 A_6 A_9
ClNO3|column number|molecules cm-2|zenith|gphy_air|remote|S_1 S_2|X_1 A_5 A_6 A_9
HCl|column number|molecules cm-2|zenith|gphy_air|remote|S_1 S_2|X_1 A_5 A_6 A_9
HF|column number|molecules cm-2|zenith|gphy_air|remote|S_1 S_2|X_1 A_5 A_6 A_9
H2O|column number|molecules cm-2|zenith|gphy_air|remote|S_1 S_2|X_1 A_5 A_6 A_9
10 {NAUXV}
1 1 1 1 1 1 1 1 1 1 {ASCAL}
99 99 99 99 99.9 999.9 999.9 999 9999 999 {AMISS}
time | UTC_month | mon || anal | model |S_1|X_1 A_5 A_6 A_9
time | UTC day | d || anal | model |S_1|X_1 A_5 A_6 A_9
time | UTC hour | h || anal | model |S_1|X_1 A_5 A_6 A_9
time | UTC minute | min || anal | model |S_1|X_1 A_5 A_6 A_9
latitude | INS | deg || gloc_S_1 | insitu |S_2|X_1 A_6 A_9
longitude | INS | deg || gloc_S_1 | insitu |S_2|X_1 A_5 A_9
air | solar zenith angle | deg || gphy_air | model |S_2|X_1 A_5 A_6 A_9
air | temperature | Celsius || gphy_air | insitu |S_2|X_1 A_5 A_6 A_9
air | pressure | mb || gphy_air | insitu |S_2|X_1 A_5 A_6
air | potential temperature | K || gphy_air | insitu |S_2|X_1 A_5 A_6 A_9
0 {NSCOML}
15 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 320
#MD | NA | SUoffset_X | 1 | -1
#MD | NA | SUscale_X | 1 | 1
#MD | SA | SU_X | 1 | d
#MD | NA | SUoffset_V | 8 | 0 0 0 0 0 0 0 0
#MD | NA | SUscale_V | 8 | 1e+4 1e+4 1e+4 1e+4 1e+4 1e+4 1e+4 1e+4
#MD | SA | SU_V | 8 | m-2|m-2|m-2|m-2|m-2|m-2|m-2|m-2
#MD | NA | SUoffset_A | 10 | 0 0 0 0 0 0 0 273.15 0 0
#MD | NA | SUscale_A | 10 | 1 1 1 1 1 1 1 1 100 1
#MD | SA | SU_A | 10 |NULL|NULL|NULL|NULL|deg|deg|deg|K|Pa|K
#MD | SA | note_X_1 | 2
DayOfYear=1 at 1 January 00:00 UTC. The Standard Units conversion
subtracts one day to convert to the standard "days since year0".
NOTE: All these column values will change when analyses are repeated.
16.021 1 16 0 30 -5.9 -125.0 88.4 -56 237 328
80 24 75 142 12 240 72 47
16.038 1 16 0 55 -6.0 -127.1 88.5 -57 237 328
70 19 82 121 12 243 72 56
16.158 1 16 3 48 -6.4 -137.7 88.9 -57 237 327
71 16 78 118 10 237 56 49
...
7.3 FFI=1020
29 1020 {NLHEAD FFI}
MERTZ, FRED
NOAA Aeronomy Laboratory
ER-2 LYMAN-ALPHA HYGROMETER
TOP
1 1 {IVOL NVOL}
1991 01 16 1991 01 16 {DATE RDATE}
1.0 {DX(1)}
30 {NVPM(1)}
Seconds since 00Z (s)
1 {NV}
0.01 {VSCAL(1)}
999999 {VMISS(1)}
Water vapor volume mixing ratio (ppmv)
4 {NAUXV}
1.0 1.0 1.0 1.0 {ASCAL}
99 99 99 99999 {AMISS}
UTC HOUR (h)
UTC MINUTE (min)
UTC SECOND (s)
OBSERVATION COUNT STARTING FROM TIME COMPUTER IS TURNED ON (NULL)
0 {NSCOML}
6 {NNCOML}
This is PRELIMINARY data
08:05:01 COMPUTER ON
CALB 8.525E+13 4.829E+7 T = 3.000E+2 DltP = 0.000E+0
NOB 2.799E+2 -1.471E-3 -7.641E+22
OHB 1.279E+2 5.113E-4 -7.641E+22
29301.0 08 08 21 200
999999 999999 999999 999999 999999 999999 999999 999999
999999 999999 999999 999999 999999 999999 999999 999999
999999 999999 87166 84175 76721 80130 81401 79359
79887 84339 89955 97811 95614 91508
29331.0 08 08 51 230
88126 86236 79440 81826 82911 90481 92042 91391
94605 93040 87099 85103 87131 87423 82418 75260
64485 59903 63633 68262 72430 75216 78814 77879
72445 69610 66126 60302 55169 48993
29361.0 08 09 21 260
39742 39137 38357 38002 36171 35267 36094 38442
40786 41725 42796 43492 44009 43589 42926 43308
999999 999999 999999 999999 999999 999999 999999 999999
999999 999999 999999 999999 999999 999999
...
34 1020 {NLHEAD FFI}
1 | 0 | MERTZ | FRED
1 | NOAA AL | fum@noaa.gov |
2 | ER-2 706 | LAH | ER-2 706 | MMS | ER-2 Lyman-Alpha Hygrometers
TOP |
1 1 {IVOL NVOL}
1991 01 16 1991 01 16 {DATE RDATE}
1.0 {DX(1)}
30 {NVPM(1)}
time | seconds | s || gloc | model |S_1|S_2
1 {NV}
0.01 {VSCAL(1)}
999999 {VMISS(1)}
H2O vapor|volume mixing ratio|ppmv||gphy_air|insitu|S_1|X_1 S_2
4 {NAUXV}
1.0 1.0 1.0 1.0 {ASCAL}
99 99 99 99999 {AMISS}
time | UTC hour | h || anal | model |S_1|X_1 S_2
time | UTC minute | min || anal | model |S_1|X_1 S_2
time | UTC second | s || anal | model |S_1|X_1 S_2
observation number|count|NULL|from computer startup|anal|user|S_1|X_1 S_2
0 {NSCOML}
11 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 704
#MD | NA | SUoffset_V | 1 | 0
#MD | NA | SUscale_V | 1 | 1.0E-6
#MD | SA | SU_V | 1 | 1
This is PRELIMINARY data
08:05:01 COMPUTER ON
CALB 8.525E+13 4.829E+7 T = 3.000E+2 DltP = 0.000E+0
NOB 2.799E+2 -1.471E-3 -7.641E+22
OHB 1.279E+2 5.113E-4 -7.641E+22
29301.0 08 08 21 200
999999 999999 999999 999999 999999 999999 999999 999999
999999 999999 999999 999999 999999 999999 999999 999999
999999 999999 87166 84175 76721 80130 81401 79359
79887 84339 89955 97811 95614 91508
29331.0 08 08 51 230
88126 86236 79440 81826 82911 90481 92042 91391
94605 93040 87099 85103 87131 87423 82418 75260
64485 59903 63633 68262 72430 75216 78814 77879
72445 69610 66126 60302 55169 48993
29361.0 08 09 21 260
39742 39137 38357 38002 36171 35267 36094 38442
40786 41725 42796 43492 44009 43589 42926 43308
999999 999999 999999 999999 999999 999999 999999 999999
999999 999999 999999 999999 999999 999999
...
7.4 FFI=2010
39 2010 {NLHEAD FFI}
Mertz, Fred
University of Denver; fum@du.edu
WB-57 FCAS Aerosol size distribution
TOP II
1 1 {IVOL
NVOL}
2005 01 16 2005 02 15 {DATE
RDATE}
0.0 30.0 {DX(1)
DX(2)}
32 {NX(1)}
32 {NXDEF(1)}
0.060 0.068 0.078 0.089 0.101 0.115 0.131 0.149
0.169 0.193 0.219 0.250 0.284 0.323 0.368 0.419
0.477 0.543 0.618 0.703 0.801 0.912 1.038 1.181
1.34 1.53 1.74 1.98 2.25 2.56 2.92 3.33
Diameter Range, Lower limit (microns)
Time, seconds from midnight (UTS)
1 {NV}
1.0 {VSCAL(1)}
9.99e+09 {VMISS(1)}
Particle Mixing Ratio in Specified size Bins (#/mg Air)
3 {NAUXV}
1 1 1 {ASCAL}
99.99 99.99 99.99 {AMISS}
Ambient Air Density (mg/cu. cm)
Density of Particle (g/cu. cm)
Mass fraction of H2SO4 (g H2SO4/g particles)
0 {NSCOML}
11 {NNCOML}
Size distributions are measured with a Focused Cavity Aerosol
Spectrometer (FCAS II). Size is measured at laser.
Reported size is adjusted to account for evaporation in sampling
and transport.
Concentrations adjusted to account for effects of anisokinetic sampling.
Mass fraction of sulfuric acid is calculated from theory.
Mass fraction of sulfuric acid depends upon pressure, temperature
and water vapor.
Water vapor, pressure and temperature are measured by other investigators.
The particle mixing ratios in the channel with the smallest
diameter that has particles are underestimates.
56620 0.665 1.563 0.633
9.99e+09 9.99e+09 9.99e+09 6.24e+00 1.27e+01 1.97e+01 1.91e+01 1.64e+01
1.09e+01 6.61e+00 4.50e+00 3.51e+00 2.70e+00 1.26e+00 9.53e-01 4.66e-01
2.68e-01 1.78e-01 1.47e-01 9.53e-02 3.27e-02 1.43e-02 1.31e-02 1.40e-02
9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09
56650 0.635 1.509 0.583
9.99e+09 9.99e+09 9.99e+09 9.99e+09 2.85e+01 3.06e+01 3.19e+01 2.67e+01
1.92e+01 1.07e+01 7.63e+00 5.38e+00 4.82e+00 2.70e+00 1.79e+00 7.13e-01
3.50e-01 9.71e-02 5.67e-02 4.99e-02 3.07e-02 4.21e-03 6.33e-02 1.26e-01
9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09
56680 0.605 1.451 0.525
9.99e+09 9.99e+09 9.99e+09 9.99e+09 2.13e+01 3.73e+01 5.38e+01 4.24e+01
3.09e+01 1.62e+01 1.06e+01 8.78e+00 7.78e+00 6.15e+00 3.35e+00 1.96e+00
9.50e-01 3.24e-01 1.15e-01 1.42e-01 1.33e-01 9.32e-02 4.16e-02 2.91e-03
9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09
...
52 2010 {NLHEAD FFI}
1 | 0 | Mertz | Fred
1 | DU | fum@du.edu |
3 |WB-57 926|FCAS II|WB-57 926|MMS|WB-57 926|HUWV|Aerosol size distribution
TOP II |
1 1 {IVOL
NVOL}
2005 01 16 2005 02 15 {DATE
RDATE}
0.0 30.0 {DX(1)
DX(2)}
32 {NX(1)}
32 {NXDEF(1)}
0.060 0.068 0.078 0.089 0.101 0.115 0.131 0.149
0.169 0.193 0.219 0.250 0.284 0.323 0.368 0.419
0.477 0.543 0.618 0.703 0.801 0.912 1.038 1.181
1.34 1.53 1.74 1.98 2.25 2.56 2.92 3.33
aerosol|diameter|microns|size bin lower limit|gphy_air|insitu|S_1|X_2 S_2
time|seconds|s|sync to MMS|gloc|model|S_1 S_2|S_2
1 {NV}
1.0 {VSCAL(1)}
9.99e+09 {VMISS(1)}
aerosol|specific number|#/mg Air||gphy_air|insitu|S_1 S_2|X_2 S_2
3 {NAUXV}
1 1 1 {ASCAL}
99.99 99.99 99.99 {AMISS}
air|mass concentration|mg/cu. cm||gphy_air|insitu|S_2|X_2 S_2
aerosol|mass density|g/cu. cm||gphy_air|insitu|S_1 S_2|X_2 S_2
H2SO4|aerosol mass fraction|g H2SO4/g particles||gphy_air|model &
|S_1 S_2 S_3|X_2 S_2
0 {NSCOML}
24 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 254
#MD | NA | SUoffset_X | 2 | 0 0
#MD | NA | SUscale_X | 2 | 1e-6 1
#MD | SA | SU_X | 2 | m | s
#MD | NA | SUoffset_V | 1 | 0
#MD | NA | SUscale_V | 1 | 1e+6
#MD | SA | SU_V | 1 | kg-1
#MD | NA | SUoffset_A | 3 | 0 0 0
#MD | NA | SUscale_A | 3 | 1 1e+3 1
#MD | SA | SU_A | 3 | kg m-3 | kg m-3 | 1
#MD | SA | note_A_3 | 4
Mass fraction of sulfuric acid is calculated from theory.
Mass fraction of sulfuric acid depends upon pressure, temperature
and water vapor.
Water vapor, pressure and temperature are measured by other investigators.
Size distributions are measured with a Focused Cavity Aerosol
Spectrometer (FCAS II). Size is measured at laser.
Reported size is adjusted to account for evaporation in sampling
and transport.
Concentrations adjusted to account for effects of anisokinetic sampling.
The particle mixing ratios in the channel with the smallest
diameter that has particles are underestimates.
56620 0.665 1.563 0.633
9.99e+09 9.99e+09 9.99e+09 6.24e+00 1.27e+01 1.97e+01 1.91e+01 1.64e+01
1.09e+01 6.61e+00 4.50e+00 3.51e+00 2.70e+00 1.26e+00 9.53e-01 4.66e-01
2.68e-01 1.78e-01 1.47e-01 9.53e-02 3.27e-02 1.43e-02 1.31e-02 1.40e-02
9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09
56650 0.635 1.509 0.583
9.99e+09 9.99e+09 9.99e+09 9.99e+09 2.85e+01 3.06e+01 3.19e+01 2.67e+01
1.92e+01 1.07e+01 7.63e+00 5.38e+00 4.82e+00 2.70e+00 1.79e+00 7.13e-01
3.50e-01 9.71e-02 5.67e-02 4.99e-02 3.07e-02 4.21e-03 6.33e-02 1.26e-01
9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09
56680 0.605 1.451 0.525
9.99e+09 9.99e+09 9.99e+09 9.99e+09 2.13e+01 3.73e+01 5.38e+01 4.24e+01
3.09e+01 1.62e+01 1.06e+01 8.78e+00 7.78e+00 6.15e+00 3.35e+00 1.96e+00
9.50e-01 3.24e-01 1.15e-01 1.42e-01 1.33e-01 9.32e-02 4.16e-02 2.91e-03
9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09 9.99e+09
...
7.5 FFI=2110
30 2110 {NLHEAD
FFI}
Mertz, Fred
NASA JPL; fum@nasa.gov
ER-2 Microwave Temperature Profiler (MTP)
TOP
1 1 {IVOL NVOL}
1991 1 16 1991 1 16 {DATE RDATE}
0.0 0.0 {DX(1) DX(2)}
Remote sensing "applicable altitude" (m)
Seconds since 00Z (s)
2 {NV}
1 1 {VSCAL}
999.9 99.9 {VMISS}
Brightness temperature (K)
Brightness temperature error (K)
7 {NAUXV}
1 1 1 1 1 1 1 {ASCAL}
99 99999 99.999 999.999 99.9 99.9 999.9 {AMISS}
Number of "applicable altitudes" recorded in subsequent data records (NULL)
Pressure altitude of ER-2 (m)
Latitude (deg)
Longitude (deg)
Aircraft pitch (deg)
Aircraft roll (deg)
Horizon brightness temperature (K), ave. of Chan 1 & 2 brightness temp.
0 {NSCOML}
3 {NNCOML}
The brightness temperatures are approximately equal to air
temperatures at ER-2 altitudes.
59461 5 14460 -17.764 -125.102 1.5 -0.3 212.0
23470 211.9 2.5
21370 209.1 2.1
19670 206.5 1.7
18460 205.8 1.3
17660 205.5 1.1
59475 7 14495 -17.779 -125.076 1.6 -0.3 211.7
25895 215.6 2.9
23495 210.9 2.5
21395 207.8 2.1
19695 205.0 1.7
18495 204.9 1.3
17695 205.0 1.1
16995 205.9 0.9
...
36 2110 {NLHEAD FFI}
1 | 0 | Mertz | Fred
1 | NASA JPL | fum@nasa.gov |
2 |ER-2 706| MTP |ER-2 706| MMS | ER-2 Microwave Temperature Profiler
TOP |
1 1 {IVOL NVOL}
1991 1 16 1991 1 16 {DATE RDATE}
0.0 0.0 {DX(1) DX(2)}
altitude|barometric|m|U.S.Std.Atm.1976|gloc|remote|S_1 S_2|X_2 A_3 A_4
time|seconds|s||gloc|model|S_1 S_2|X_1 A_3 A_4
2 {NV}
1 1 {VSCAL}
999.9 99.9 {VMISS}
air|brightness temperature|K||gphy_air|remote|S_1 S_2|X_1 X_2 A_3 A_4
air|brightness temperature error|K||anal|e_V_1|S_1|X_1 X_2 A_3 A_4
7 {NAUXV}
1 1 1 1 1 1 1 {ASCAL}
99 99999 99.999 999.999 99.9 99.9 999.9 {AMISS}
altitude levels | number count | NULL || anal | user |S_1|X_2 A_3 A_4
altitude | barometric | m |of ER-2| gloc_S_1 | insitu |S_2|X_2 S_2
latitude | INS | deg || gloc | insitu |S_1 S_2|X_1 X_2 A_4
longitude| INS | deg || gloc | insitu |S_1 S_2|X_1 X_2 A_3
ER-2 706| pitch angle | deg || plat | insitu |S_2|X_2 A_2 S_2
ER-2 706| roll angle | deg || plat | insitu |S_2|X_2 A_2 S_2
air|brightness temperature|K|forward horizon|gphy_air|remote|S_1 S_2|X_2 S_2
0 {NSCOML}
9 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 1203
#MD | SA | note_A_7 | 2
This is the forward-looking horizon brightness temperature,
from the
average of channels 1 and 2, and approximates outside air
temperature.
The brightness temperatures are approximately equal to air
temperatures at ER-2 altitudes.
59461 5 14460 -17.764 -125.102 1.5 -0.3 212.0
23470 211.9 2.5
21370 209.1 2.1
19670 206.5 1.7
18460 205.8 1.3
17660 205.5 1.1
59475 7 14495 -17.779 -125.076 1.6 -0.3 211.7
25895 215.6 2.9
23495 210.9 2.5
21395 207.8 2.1
19695 205.0 1.7
18495 204.9 1.3
17695 205.0 1.1
16995 205.9 0.9
...
7.6 FFI=2160
34 2160 {NLHEAD
FFI}
Mertz, Fred
NASA ARC; fum@nasa.gov
Radiosonde observations
AASE
1 1 {IVOL NVOL}
1989 1 16 1989 1 16 {DATE RDATE}
0 {DX(1)}
5 {LENX(2)}
Pressure level (hPa)
Radiosonde station identifier (BBSSS), BB=block #, SSS=station code.
5 {NV}
1.0 0.1 0.1 1.0 0.1 {VSCAL}
99999 9999 999 999 9999 {VMISS}
Geopotential height (gpm)
Air temperature (C)
Dew-point depression (C)
Wind direction (degrees)
Wind speed (knots)
6 {NAUXV}
1 {NAUXC}
1.0 0.01 0.01 0.01 1.0 {ASCAL}
999 9999 99999 9999 9999 {AMISS}
30 {LENA(9)}
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
Number of pressure levels in the sounding (NULL)
UTC hour of launch (h)
East longitude of station (deg)
Latitude of station (deg)
Elevation of station above MSL (m)
Station name
0 {NSCOML}
1 {NNCOML}
Ship stations are in block 99.
71082
4 1200 -6233 8250 66
Alert/Ellesmere Island
850.0 1136 -331 48 235 330
700.0 3498 -363 36 999 9999
500.0 4770 -467 50 235 420
400.0 6230 -541 60 235 490
99C7C
14 1200 -3550 5270 0
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
1014.0 0 16 39 270 290
1000.0 118 6 27 280 210
...
43 2160 {NLHEAD FFI}
0 | 1 | Mertz | Fred
1 | NASA ARC | fum@nasa.gov |
2 |ground|raob|sonde|raob|Radiosonde observations at several stations.
AASE | Airborne Arctic Stratospheric Expedition
1 1 {IVOL NVOL}
1989 1 16 1989 1 16 {DATE RDATE}
0 {DX(1)}
5 {LENX(2)}
air | pressure | hPa || gphy_air | insitu |S_2|A_2 A_3 A_4 V_1
station | identifier | NULL | (BBSSS) | anal | user |S_1|A_2 A_3 A_4 A_5
5 {NV}
1.0 0.1 0.1 1.0 0.1 {VSCAL}
99999 9999 999 999 9999 {VMISS}
altitude | geopotential | m || gloc | insitu |S_2|A_2 A_3 A_4
air | temperature | C || gphy_air | insitu |S_2|A_2 A_3 A_4 V_1
air | dew-point depression | C || gphy_air | insitu |S_2|A_2 A_3 A_4 V_1
air | wind direction | deg || gphy_air | remote |S_1|A_2 A_3 A_4 V_1
air | wind speed | knots || gphy_air | remote |S_1|A_2 A_3 A_4 V_1
6 {NAUXV}
1 {NAUXC}
1.0 0.01 0.01 0.01 1.0 {ASCAL}
999 9999 99999 9999 9999 {AMISS}
30 {LENA(9)}
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
pressure levels | number count | NULL || anal | user |S_2|A_2 A_3 A_4 A_5
launch time | hours | h || gloc | model |S_1|A_3 A_4 A_5
longitude | geodetic | deg || gloc_S_1 | model |S_1|A_2 A_4 A_5
latitude | geodetic | deg || gloc_S_1 | model |S_1|A_2 A_3 A_5
altitude | geodetic | m || gloc_S_1 | model |S_1|A_2 A_3 A_4
station | name | NULL || anal | user |S_1|A_2 A_3 A_4 A_5
0 {NSCOML}
10 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 67
#MD | NA | SUoffset_X | 2 | 0 0
#MD | NA | SUscale_X | 2 | 100 1
#MD | SA | SU_X | 2 | Pa | NULL
#MD | NA | SUoffset_V | 5 | 0 273.15 0 0 0
#MD | NA | SUscale_V | 5 | 1 1 1 1 0.5144
#MD | SA | SU_V | 5 | m | K | K | deg | m s-1
#MD | SA | note_X_2 | 2 | BBSSS: BB=block #; SSS=station code
Ship stations are in block 99.
71082
4 1200 -6233 8250 66
Alert/Ellesmere Island
850.0 1136 -331 48 235 330
700.0 3498 -363 36 999 9999
500.0 4770 -467 50 235 420
400.0 6230 -541 60 235 490
99C7C
14 1200 -3550 5270 0
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
1014.0 0 16 39 270 290
1000.0 118 6 27 280 210
...
7.7 FFI=2310
33 2310 {NLHEAD FFI}
Mertz, Fred
NASA LaRC; fum@nasa.gov
DC-8 DIAL ozone number densities
TOP II|Tahiti Ozone Project II
1 1 {IVOL NVOL}
2005 1 16 2005 2 20 {DATE RDATE}
0.0 {DX(2)}
Geometric altitude of observation (m)
Seconds since 00Z (s)
1 {NV}
1.0E+09 {VSCAL}
99999 {VMISS}
Ozone number density (#/cc)
9 {NAUXV}
1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.01 0.01 {ASCAL}
999 99999 999 99999 99 99 99 99999 9999 {AMISS}
Number of altitudes for current time mark (NULL)
Geometric altitude (m) at which data begins
Altitude increment (m)
Geometric altitude of aircraft (m)
UTC Hour (h)
UTC Minute (min)
UTC Second (s)
East longitude (deg)
Latitude (deg)
0 {NSCOML}
5 {NNCOML}
VERTICAL AVERAGING INTERVAL: 975 METERS AT 1-7 KM ABOVE AIRCRAFT
2025 METERS > 7 KM ABOVE AIRCRAFT
(TRANSITION RANGE VARIES WITH SIGNAL STRENGTH)
HORIZONTAL AVERAGING INTERVAL: 60 KM
30335 26 12819 75 10389 8 25 35 -13324 -945
1340 1519 1660 1779 1868 1939 1973 1992 1989 1955
1934 1897 1817 1721 1619 1514 1434 1343 1258 1203
1140 1088 1037 956 892 878
30360 22 12819 75 10383 8 26 0 -13322 -993
1351 1523 1658 1774 1860 1930 1962 1974 1966 1932
1909 1877 1803 1706 1600 1493 1407 1310 99999 99999
1094 1045
30384 93 12744 75 10378 8 26 24 -13312 -1031
934 1378 1541 1673 1782 1862 1925 1950 1956 1946
1912 1884 1843 1765 1667 1565 1457 1375 1279 1194
...
38 2310 {NLHEAD FFI}
1 | 0 | Mertz | Fred U.
1 | NASA LaRC | fum@nasa.gov |
2 |DC-8 817| DIAL |DC-8 817| ICATS | DC-8 DIAL ozone number densities
TOP II | Tahiti Ozone Project II
1 1 {IVOL NVOL}
2005 1 16 2005 2 20 {DATE RDATE}
0.0 {DX(2)}
altitude | geometric | m || gloc | remote |S_1 S_2|X_2 A_8 A_9
time | seconds | s || gloc | model |S_2|X_1 A_8 A_9
1 {NV}
1.0E+09 {VSCAL}
99999 {VMISS}
O3|number concentration|#/cc||gphy_air|remote|S_1 S_2|X_1 X_2 A_8 A_9
9 {NAUXV}
1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.01 0.01 {ASCAL}
999 99999 999 99999 99 99 99 99999 9999 {AMISS}
altitude levels|number count|NULL||anal|user|S_1|X_2 A_8 A_9
altitude|geometric|m|at which data begins|gloc|remote|S_1 S_2|X_2 A_8 A_9
altitude|geometric|m|increment|anal|user|S_1|X_2 A_8 A_9
altitude|GPS|m|of DC8|gloc_S_2|remote|S_2|X_2 A_8 A_9
time|UTC hour|h||anal|model|S_2|X_1 X_2 A_8 A_9
time|UTC minute|min||anal|model|S_2|X_1 X_2 A_8 A_9
time|UTC second|s||anal|model|S_2|X_1 X_2 A_8 A_9
longitude|GPS|deg||gloc_S_2|remote|S_2|X_2 A_4 A_9
latitude|GPS|deg||gloc_S_2|remote|S_2|X_2 A_4 A_8
0 {NSCOML}
10 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 575
#MD | NA | SUoffset_V | 1 | 0
#MD | NA | SUscale_V | 1 | 1.0E+6
#MD | SA | SU_V | 1 | m-3
VERTICAL AVERAGING INTERVAL: 975 METERS AT 1-7 KM ABOVE AIRCRAFT
2025 METERS > 7 KM ABOVE AIRCRAFT
(TRANSITION RANGE VARIES WITH SIGNAL STRENGTH)
HORIZONTAL AVERAGING INTERVAL: 60 KM
30335 26 12819 75 10389 8 25 35 -13324 -945
1340 1519 1660 1779 1868 1939 1973 1992 1989 1955
1934 1897 1817 1721 1619 1514 1434 1343 1258 1203
1140 1088 1037 956 892 878
30360 22 12819 75 10383 8 26 0 -13322 -993
1351 1523 1658 1774 1860 1930 1962 1974 1966 1932
1909 1877 1803 1706 1600 1493 1407 1310 99999 99999
1094 1045
30384 93 12744 75 10378 8 26 24 -13312 -1031
934 1378 1541 1673 1782 1862 1925 1950 1956 1946
1912 1884 1843 1765 1667 1565 1457 1375 1279 1194
...
7.8 FFI=3010
26 3010 {NLHEAD
FFI}
Mertz, Fred
NASA GSFC; fum@nasa.gov
NASA GSFC Data Assimilation Model grid point analyses
AASE
1 1 {IVOL NVOL}
1989 1 16 1989 1 16 {DATE RDATE}
5.0 2.5 12.0 {DX(1) DX(2) DX(3)}
8 3 {NX(1) NX(2)}
1 1 {NXDEF(1) NXDEF(2)}
-25 {X(1,1); X(i,1) = -25 -20 -15 -10 -5 0 5 10}
60.0 {X(1,2); X(j,2) = 60 62.5 65}
East longitude (deg)
Latitude (deg)
Hours since 00Z (h)
2 {NV}
1.0E-08 0.1 {VSCAL}
99999 9999 {VMISS}
Potential vorticity (K m2 kg-1 s-1)
Temperature (K)
1 {NAUXV}
1 {ASCAL}
999.9 {AMISS}
Potential temperature (K)
0 {NSCOML}
0 {NNCOML}
0 400
1604 1597 1589 1578 1570 1578 1584 1589 {PV rec}
1598 1583 1561 1534 1506 1478 1447 1446 {PV rec}
1440 1439 1442 1469 1493 1512 1527 1537 {PV rec}
2234 2251 2259 2250 2247 2200 2194 2187 { T rec}
2194 2151 2159 2150 2147 2166 2175 2165 { T rec}
2121 2136 2140 2140 2138 2127 2111 2104 { T rec}
12 400
1532 1522 1509 1492 1472 1467 1459 1450 {PV rec}
1419 1433 1448 1465 1483 1503 1525 1567 {PV rec}
1670 1691 1711 1724 1737 1744 1745 1743 {PV rec}
2224 2241 2249 2240 2237 2200 2184 2177 { T rec}
2184 2141 2149 2140 2137 2156 2165 2155 { T rec}
2111 2126 2130 2130 2128 2117 2101 2101 { T rec}
24 400
1587 1578 1569 1558 1546 1533 1641 1626
...
28 3010 {NLHEAD FFI}
0 | 1 | Mertz | Fred
1 | NASA GSFC | fum@nasa.gov |
1 | model | GSFCAM |grid point analyses on isentropic surface
AASE |
1 1 {IVOL NVOL}
1989 1 16 1989 1 16 {DATE RDATE}
5.0 2.5 12.0 {DX(1) DX(2) DX(3)}
8 3 {NX(1) NX(2)}
1 1 {NXDEF(1) NXDEF(2)}
-25 {X(1,1); X(i,1)= -25 -20 -15 -10 -5 0 5 10}
60.0 {X(1,2); X(j,2)= 60 62.5 65}
longitude | spherical | deg || gloc | model |S_1|X_2 X_3 A_1
latitude | spherical | deg || gloc | model |S_1|X_1 X_3 A_1
time | hours | h || gloc | model |S_1|X_1 X_2 A_1
2 {NV}
1.0E-08 0.1 {VSCAL}
99999 9999 {VMISS}
air|potential vorticity|K m2 kg-1 s-1||gphy_air|model|S_1|X_1 X_2 X_3 A_1
air|temperature|K||gphy_air|model|S_1|X_1 X_2 X_3 A_1
1 {NAUXV}
1 {ASCAL}
999.9 {AMISS}
air | potential temperature | K || gphy_air | model |S_1|X_1 X_2 X_3
0 {NSCOML}
2 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 4
0 400
1604 1597 1589 1578 1570 1578 1584 1589 {PV rec}
1598 1583 1561 1534 1506 1478 1447 1446 {PV rec}
1440 1439 1442 1469 1493 1512 1527 1537 {PV rec}
2234 2251 2259 2250 2247 2200 2194 2187 { T rec}
2194 2151 2159 2150 2147 2166 2175 2165 { T rec}
2121 2136 2140 2140 2138 2127 2111 2104 { T rec}
12 400
1532 1522 1509 1492 1472 1467 1459 1450 {PV rec}
1419 1433 1448 1465 1483 1503 1525 1567 {PV rec}
1670 1691 1711 1724 1737 1744 1745 1743 {PV rec}
2224 2241 2249 2240 2237 2200 2184 2177 { T rec}
2184 2141 2149 2140 2137 2156 2165 2155 { T rec}
2111 2126 2130 2130 2128 2117 2101 2101 { T rec}
24 400
1587 1578 1569 1558 1546 1533 1641 1626
...
7.9 FFI=4010
24 4010 {NLHEAD FFI}
Mertz, Fred
NASA GSFC; fum@nasa.gov
NASA GSFC Data Assimilation Model grid point analyses
AASE
1 1 {IVOL NVOL}
1989 1 16 1989 1 16 {DATE RDATE}
5.0 2.5 40.0 0.0 {DX(1) DX(2) DX(3) DX(4)}
8 3 2 {NX(1) NX(2) NX(3)}
1 1 2 {NXDEF(1) NXDEF(2) NXDEF(3)}
-25 {X(1,1); X(i,1)= -25 -20 -15 -10 -5 0 5 10}
60.0 {X(1,2); X(j,2)= 60 62.5 65}
400 440 {X(k,3)}
East longitude (deg)
Latitude (deg)
Potential temperature (K)
Hours since 00Z (h)
1 {NV}
1.0E-08 {VSCAL}
99999 {VMISS}
Potential vorticity (K m2 kg-1 s-1)
0 {NAUXV}
0 {NSCOML}
0 {NNCOML}
0
1604 1597 1589 1578 1570 1578 1584 1589
1598 1583 1561 1534 1506 1478 1447 1446
1440 1439 1442 1469 1493 1512 1527 1537 {last 400K rec}
3135 3151 3175 3198 3220 3240 3260 3278
3326 3348 3369 3389 3409 3428 3446 3465
3498 3492 3485 3476 3468 3459 3464 3446 {last 440K rec}
12
1532 1522 1509 1492 1472 1467 1459 1450
1419 1433 1448 1465 1483 1503 1525 1567
1670 1691 1711 1724 1737 1744 1745 1743 {last 400K rec}
3424 3419 3409 3396 3379 3354 3327 3297
3193 3158 3125 3095 3065 3037 3011 2998
2956 2938 2920 2914 2909 2906 2905 2906 {last 440K rec}
36
1587 1578 1569 1558 1546 1533 1641 1626
...
26 4010 {NLHEAD FFI}
0 | 1 | Mertz | Fred
1 | NASA GSFC | fum@nasa.gov |
1 | model | GSFCAM | grid point analyses on isentropic
surfaces
AASE |
1 1 {IVOL NVOL}
1989 1 16 1989 1 16 {DATE RDATE}
5.0 2.5 40.0 0.0 {DX(1) DX(2) DX(3) DX(4)}
8 3 2 {NX(1) NX(2) NX(3)}
1 1 2 {NXDEF(1) NXDEF(2) NXDEF(3)}
-25 {X(1,1); X(i,1)= -25 -20 -15 -10 -5 0 5 10}
60.0 {X(1,2); X(j,2)= 60 62.5 65}
400 440 {X(k,3)}
longitude | spherical | deg || gloc | model |S_1|X_2 X_3 X_4
latitude | spherical | deg || gloc | model |S_1|X_1 X_3 X_4
air | potential temperature | K || gphy_air | model |S_1|X_1 X_2 X_4
time | hours | h || gloc | model |S_1|X_1 X_2 X_3
1 {NV}
1.0E-08 {VSCAL}
99999 {VMISS}
air|potential vorticity|K m2 kg-1 s-1||gphy_air|model|S_1|X_1 X_2 X_3 X_4
0 {NAUXV}
0 {NSCOML}
2 {NNCOML}
#MD | NA | format version | 1 | 2
#MD | NA | NIVM | 1 | 7
0
1604 1597 1589 1578 1570 1578 1584 1589
1598 1583 1561 1534 1506 1478 1447 1446
1440 1439 1442 1469 1493 1512 1527 1537 {last 400K rec}
3135 3151 3175 3198 3220 3240 3260 3278
3326 3348 3369 3389 3409 3428 3446 3465
3498 3492 3485 3476 3468 3459 3464 3446 {last 440K rec}
12
1532 1522 1509 1492 1472 1467 1459 1450
1419 1433 1448 1465 1483 1503 1525 1567
1670 1691 1711 1724 1737 1744 1745 1743 {last 400K rec}
3424 3419 3409 3396 3379 3354 3327 3297
3193 3158 3125 3095 3065 3037 3011 2998
2956 2938 2920 2914 2909 2906 2905 2906 {last 440K rec}
36
1587 1578 1569 1558 1546 1533 1641 1626
...