Gulfstream III - LaRC

The NASA Langley airborne High-Spectral-Resolution Lidar – Generation 2 (HSRL-2) is used to characterize clouds and small particles in the atmosphere, called aerosols. From an airborne platform, the HSRL-2 instrument provides nadir-viewing profiles of aerosol and cloud optical and microphysical properties, which are used studies aerosol impacts on radiation, clouds, and air quality. HSRL-2 also provides measurements of the near-surface ocean, including depth-resolved subsurface backscatter and attenuation. HSRL-2 can also be configured to utilize the differential absorption (DIAL) technique for measuring profiles of ozone concentrations in addition to the above products.

Principle: The CU aircraft version of the Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) detects non-refractory submicron aerosol composition by impaction on a vaporizer at 600°C, followed by electron ionization and time-of-flight mass spectral analysis. Size-resolved composition can be quantified by measuring the arrival times of the aerosol at the vaporizer.

Aircraft Operation: (1 min cycles, can be adjusted to meet mission goals):
46 s total concentration measurements (1 s resolution, can be increased to up to 10 Hz upon request)
5 s speciated size distribution measurements (with improved S/N detection due to ePToF acquisition)
9 s Background + Overhead
Higher accuracy due to flight day calibrations using built-in system
Custom pressure controlled inlet with confirmed performance up to 45 kft

Real Time Data Products:
PM1 Aerosol Mass Concentrations:
Organic aerosol (OA) , SO4, NO3, NH4, Chloride 
OA Chemical Markers: f44 (Secondary OA), f57 (hydrocarbon-like OA), f60 (biomass burning OA), f82 (isoprene epoxide-SOA), other fx upon request

More Advanced Products:
- PM1 Seasalt, ClO4, total I, total Br, MSA concentrations
- O/C, H/C, OA/OC, OSc
- Particle organic nitrates (pRONO2)
- Ammonium Balance, estimated pH
- OA components by positive matrix factorization (PMF)
- Particle eddy covariance fluxes of all species
- Speciated Aerosol size distributions

Detection Limits (1s, ng sm-3), (1 min, ng sm-3) from start of the flight (due to custom cryopump):
Sulfate: 40, 15
Nitrate: 15, 6
Ammonium: 3, 1
Chloride: 30, 12
OA: 200, 80
For detailed OA analysis, longer averaging (3-30 s, depending on OA concentration) is needed. A 1 min product is hence provided as well.

The SP2 is a laser-induced incandescence instrument primarily used for measuring the refractory BC  (rBC) mass content of individual accumulation-mode aerosol particles. It is able to provide this data product independently of the total particle morphology and mixing state, and thus delivers detailed information not only about BC loadings, but also size distributions, even in exceptionally clean air. The instrument can also provide the optical size of individual particles containing rBC, and identify the presence of materials associated with the BC fraction (i.e. identify the rBC’s mixing state). Since its introduction in 2003, the SP2 has been substantially improved, and now can be considered a highly competent instrument for assessing BC loadings and mixing state in situ.  NOAA deploys multiple SP2s with different designs: the first was built for the WB-57F research aircraft. Two others are rack-mounted units customized at NOAA; one of the rack mounted units can be humidified, and has been deployed with a paired dry rack-mounted SP2 as the "Humidified-Dual SP2" (HD-SP2). The rack mounted units are suitable for in-cabin operations.

The coastal zone is home to a high fraction of humanity and increasingly affected by natural and human-induced events from tsunamis to toxic tidal blooms. Current satellite data provide a broad overview of these events but do not have the necessary spectral, spatial and temporal, resolution to characterize and understand these events.

To address this gap, a compact, lightweight, airborne Portable Remote Imaging SpectroMeter (PRISM) compatible with a wide range of piloted and Uninhabited Aerial Vehicle (UAV) platforms are curently being developed at the Jet Propulsion Laboratory. Operating between the spectral range of 350 nm and 1050 nm, PRISM will offer high temporal resolution and below cloud flight altitudes to resolve spatial features as small as 30 cm. The sensor performance exceeds the state of the art in light throughput, spectral and spatial uniformity, and polarization insensitivity by factors of 2-10, while at the same time extending the spectral range into the ultraviolet. PRISM will also have a two-channel spot radiometer at short-wave infrared (SWIR) band (1240 nm and 1640 nm). It will be in co-alignment with the spectrometer in order to provide accurate atmospheric correction of the ocean color measurements.

The development of the PRISM instrument is supported by NASA Earth Science Division’s the Ocean Biology and Biogeochemistry, Earth Science Technology, and Airborne Sciences programs within NASA’s Earth Science Division.

NASA’s Land, Vegetation and Ice Sensor (LVIS) is a wide-swath, high-altitude, full-waveform airborne laser altimeter and camera sensor suite designed to provide elevation and surface structure measurements over hundreds of thousands of square kilometers. LVIS is an efficient and cost-effective capability for mapping land, water, and ice surface topography, vegetation height and vertical structure, and surface dynamics. The LVIS Facility is comprised of two high-altitude scanning lidar systems plus cameras that have been integrated on numerous NASA, NSF, and commercial aircraft platforms providing a diverse and flexible capability to meet a broad range of science needs. The newest Facility lidar (LVIS-F) began operations in 2017 using a 4,000 Hz laser, and an earlier 1,000 Hz sensor built in 2010 has undergone various upgrades (LVIS-Classic). High-resolution, commercial off-the-shelf cameras are co-mounted with LVIS lidars providing geotagged image coverage across the LVIS swath. LVIS sensors have flown extensively for a wide range of science applications and have been installed on over a dozen different aircraft, most recently on NASA’s high-altitude Gulfstream-V jet based at Johnson Space Center

The LVIS lidars are full-waveform laser altimeters, meaning that the systems digitally record both the outgoing and reflected laser pulse shapes providing a true 3-dimensional record of the surface and centimeter-level range precision. Multiple science data products are available for each footprint, including the geolocated waveform vector, sub-canopy topography, canopy or structure height, surface complexity, and others. LVIS lidars map a ±6 degree wide data swath centered on nadir (e.g., at an operating altitude of 10 km, the data swath is 2 km wide). They are designed to fly at higher altitudes than what is typical for commercial lidars in order to map a wider swath with low incidence angles, avoid the need for terrain following, while operating at much higher speeds that maximize the range of the aircraft. Recent data campaigns include deployments to Antarctica, Greenland, Canada, Alaska, the conterminous US, Central America, French Guiana, and Gabon.

The Hyperspectral Thermal Emissions Spectrometer (HyTES) instrument has 512 pixels across track with pixel sizes in the range of 5 to 50 m depending on aircraft flying height and 256 spectral channels between 7.5 and 12 µm. The HyTES design is built upon a Quantum Well Infrared Photodetector (QWIP) focal plane array (FPA) , a cryo-cooled Dyson Spectrometer and a high-efficiency, concave blazed grating, produced using E-beam lithography.

HyTES will be useful for a number of applications, including high-resolution surface temperature and emissivity measurements and volcano observations. HyTES measurements will also be used to help determine scientifically optimal band locations for the thermal infrared (TIR) instrument for the Decadal HyspIRI mission.

The Charged-coupled device Actinic Flux Spectroradiometers (CAFS) instruments measure in situ down- and up-welling radiation and combine to provide 4 pi steradian actinic flux density spectra from 280 to 650 nm. The sampling resolution is ~0.8 nm with a full width at half maximum (FWHM) of 1.7 nm at 297 nm. From the measured flux, photolysis frequencies are calculated for ~40 important atmospheric trace gases including O3, NO2, HCHO, HONO and NO3 using a modified version of the NCAR Tropospheric Ultraviolet and Visible (TUV) radiative transfer model. The absolute spectral sensitivity of the instruments is determined in the laboratory with 1000 W NIST-traceable tungsten-halogen lamps with a wavelength dependent uncertainty of 3–5%. During deployments, spectral sensitivity is assessed with secondary calibration lamps while wavelength assignment is tracked with Hg line sources and comparisons to spectral features in the extraterrestrial flux. The optical collectors are characterized for angular and azimuthal response and the effective planar receptor distance. CAFS have an excellent legacy of performance on the NASA DC-8 and WB-57 platforms during atmospheric chemistry and satellite validation mission. These include AVE Houston 2004 and 2005, PAVE, CR-AVE, TC4, ARCTAS, DC3, SEAC4RS, KORUS-AQ, ATom and FIREX-AQ. For FIREX-AQ, upgraded electronics and cooling reduced noise and allowed for a decrease to 1 Hz acquisition.

The NASA Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has been in operation since 1989 acquiring contiguous spectral measurements between 380 and 2510 nm for use by a range of terrestrial ecology science investigations related to: (1) pattern and spatial distribution of ecosystems and their components, (2) ecosystem function, physiology and seasonal activity, (3) biogeochemical cycles, (3) changes in disturbance activity, and (4) ecosystems and human health. While AVIRIS continue to make unique and significant science contributions, such as its deployment to the Gulf of Louisiana in May 2010 for the assessment of the amount of oil spilled by the offshore well, the need for a new sensor to share AVIRIS’ workload and to eventually replace AVIRIS is inevitable. Indeed, since the late summer of 2009 a new NASA Earth Science airborne sensor called the Next Generation Airborne Visible/Infrared Imaging Spectrometer (AVIRISng) is being developed by JPL through the funding support from the American Recovery and Reinvestment Act (ARRA). The technical and programmatic oversights of the AVIRISng development is provided by NASA’s Earth Science Technology Office (ESTO).

Similar to its predecessor, the AVIRIS-NG is being designed to be compatible with a broad array of possible aircraft platforms, such as NASA’s ER-2 jet, the Twin Otter turboprop, B200 King Air, and NASA’s Gulfstream III and V.