Gas and Aerosol Measurement Sensor/Langley Airborne A-Band Spectrometer

Status

Operated By
PI

GAMS/LAABS is a combination of the Gas and Aerosol Measurement System (GAMS) and the Langley Airborne A-Band Spectrometer (LAABS). The instruments are optically co-aligned and use a common pointing system to track the Sun through an aircraft view port. In the field the instrument provides line-of-sight (LOS) O3, NO2, O4, and water vapor measurements using both a SAGE III-like multiple linear regression algorithm and a full spectrum algorithm. Aerosol may also be derived for ‘enhanced’ conditions including polar stratospheric clouds and optically thin cirrus. Using profile data (1-D/2-D) transformed to GAMS/LAABS LOS geometry, quick-look validation/comparison products for SAGE III, AROTAL, AATS-14, SCIAMACHY, and other instruments will be obtained. The data from GAMS/LAABS will make possible crucial evaluations of SAGE III data processing possible following deployment. These activities include SAGE III etaloning/mirror correction validation, O2 spectroscopy and forward model verification, ozone spectroscopy near the O2 A band and 940-nm water vapor features, evaluation of the relative strength of spectroscopic features (e.g., water vapor features at 600 nm and 940 nm) and altitude registration validation using oxygen measurements.

Instrument Details:

Gas and Aerosol Measurement Sensor (GAMS)

o Solar spectrometer with 1024 channels from ~ 430 to 1030 nm
o Provides measurements of LOS transmission spectra and
differential O3, H2O, O2, O4, and aerosol
o Solar imager to monitor scene homogeneity
o Focus on UV-Vis-Near-IR solar occultation only
o Designed to extend the technique into the troposphere
o Built space flight-like spectrometer, telescope, photon-to-bits
boards, & MCM (detector controller).
o COTS imager to establish imager performance requirements

Langley Airborne A-Band Spectrometer (LAABS)

• High spectral resolution (~0.035 nm) grating spectrometer with > 800
channels from ~759 to 771 nm
• Provides measurements of LOS transmission spectra for evaluation of
SAGE III O2 A-band forward model
• Originally developed to support CALIPSO (formerly PICASSO-CENA)
spaceborne A-band spectrometer
• Designed and fabricated by BATC to provide high spectral resolution
(~0.035 nm) radiance measurements in O2 A-band spectral region
(~765 nm)

Measurements
Aircraft
Point(s) of Contact
(POC; PI)