Airborne Instrument Technology Transition (AITT) solicitation

Five ESTO Instruments Awarded Funding for Airborne Integration
August 10, 2010

The Airborne Instrument Technology Transition (AITT) program has selected five Instrument Incubator Program (IIP) technologies for integration and testing on board various NASA airplanes and UAVs. The funding awards are intended to transition the instruments into suborbital tools that can participate in field experiments, evaluate new satellite instrument concepts, and/or provide calibration and validation of satellite instruments.

The selected IIP Instruments are five of the seven total awards made by AITT from a field of 31 proposals. What follows below are abstracts for the five IIP awards.

+ Learn more about the AITT solicitation and selections

John Hair / NASA Langley Research Center
Integration of HSRL Measurement Capability into the Ozone DIAL System for Deployment on the NASA DC-8
The objective of this project is to reconfigure and upgrade the NASA Langley Research Center’s (LaRC’s) airborne Ozone (O3) Differential Absorption Lidar (DIAL) with recent technology developments from the High Spectral Resolution Lidar Instrument Incubator Program (HSRL – IIP). The combined DIAL-HSRL instrument developed under this project will enable highly accurate nadir and zenith measurements of aerosol and cloud aerosol properties from the DC-8 aircraft in addition to the already valued O3 profiles without increasing the overall instrument footprint or weight. The addition of HSRL capability will make the instrument extremely valuable for field missions focused on atmospheric composition and chemistry. Quantitative measurements of aerosols and cloud optical and microphysical properties are of high importance to NASA’s near term science objectives. The Aerosols Clouds and Ecosystems (ACE) mission recommended by the National Research Council in their Decadal Survey [2007] for Earth Science reflects these objectives. The current baseline lidar for ACE implements a multi-wavelength HSRL that enables independent measurements of aerosol backscatter and extinction. The recent success in the deployment of the HSRL on the NASA King Air B-200 over the last four years has demonstrated the science value of the increased information content provided by the HSRL technique over that provided by standard backscatter lidar technique. The DIAL system has proven to be a high priority instrument based on its successful deployment in 29 missions over the past three decades measuring O3 and attenuated aerosol backscatter profiles for both tropospheric and stratospheric studies conducted mainly on the DC-8 platform. The current DIAL implements standard backscatter lidar retrievals at mid-visible and near-IR wavelengths and is polarization sensitive at the mid-visible wavelength. To align with future satellite missions and continue to provide high priority aerosol measurements, we propose to incorporate the HSRL instrument technologies developed under IIP into the airborne DIAL system. This effort will provide a single lidar instrument that will provide full curtain profiles (i.e., both nadir and zenith) of DIAL O3 measurements and highly accurate HSRL measurements of aerosol and cloud optical properties. The upgraded lidar will be an extremely valuable instrument for future airborne sciences missions supporting NASA’s Tropospheric Composition, Upper Atmospheric Research, and Radiation Science Programs.

Chris Hostetler / NASA Langley Research Center
Modification of HSRL and RSP for ACE, GEO-CAPE, and Glory Applications from the NASA P3

The Aerosols-Clouds-Ecosystems (ACE) mission is one of the missions recommended for implementation by the National Research Council in their Decadal Survey for Earth Science. The science goal of ACE is to reduce uncertainty in climate forcing by improved understanding of two processes: aerosol-cloud interactions and the uptake of carbon dioxide by ocean ecosystems. The ACE measurements required for studies of ocean ecosystems and ocean-aerosol-cloud interactions cannot be met by current satellite sensors. The instruments called for on ACE are a radar, lidar, polarimeter, and ocean-color spectro-radiometer. All of these instruments will incorporate significant advances over their predecessors. Of the four, the lidar and polarimeter are the most cross-disciplinary: they are both required for aerosol-cloud retrievals and ocean ecosystem retrievals. New approaches in terms of technologies and retrievals have been identified as requirements for ACE, but many of these approaches have yet to be validated. Among these approaches are the combined use of lidar and polarimeter data for ocean ecosystem measurements and ocean-aerosol-cloud interactions. The Glory mission also requires ocean color estimates in order to provide accurate aerosol absorption optical depths. To assess existing ocean microphysical models for the Glory mission and ACE combined lidar-polarimeter retrieval approaches, we propose to optimize the LaRC airborne High Spectral Resolution Lidar (HSRL) for ocean subsurface measurements and retrievals of cloud extinction profiles, harden the GISS Research Scanning Polarimeter (RSP) to enable long-duration ocean-research flights, and integrate both instruments to the Wallops P-3B. The HSRL instrument will be upgraded from 23-meter to 3-meter vertical resolution for ocean surface and subsurface measurements and to retrieve profiles of cloud extinction. The RSP1 data acquisition and thermal control systems will be upgraded to improve reliability and functionality required for the continued operation of that instrument (which was completed in 1999) during the period of the Glory mission and for ACE development studies. Both of these instruments currently fly on the NASA B200 which has limited range for ocean research. Integration to the P-3B platform will enable long-range over-ocean measurements, allowing these instruments to be deployed over any ocean ecosystem, enabling studies over a large dynamic range of ocean and atmospheric conditions. The datasets acquired on future ocean-focused field campaigns from the P-3B will enable the refinement of ACE instrument requirements and the development and assessment of retrieval algorithms, including retrievals of ocean subsurface backscatter and beam attenuation profiles, sea surface wind speed, biogenically generated aerosol, cloud droplet number density, and atmospheric scattering and absorption for correction of ocean-color measurements. The information gained on subsurface measurements of coastal waters and atmospheric correction of coastal zone ocean color measurements will also significantly benefit the Geostationary Coastal and Air Pollution Events (GEO-CAPE) Decadal Survey mission.

Matthew McGill / NASA Goddard Space Flight Center
Integration of Cloud-Aerosol Transport System (CATS) to High-Altitude Research Aircraft

Lidar remote sensing is a proven useful tool for profiling the structure of atmospheric cloud and aerosol features. In addition to basic intensity information, backscattered photons inherently possess other microphysical attributes, such as Doppler shift caused by the mean motion of the scattering medium. Thus, a lidar system capable of resolving the Doppler shifts inherent to atmospheric motions can simultaneously provide information about both the scattering intensity and the particle motion.

We have been developing a new airborne instrument, the Cloud-Aerosol Transport System (CATS). The CATS instrument is a lidar that is both a Doppler lidar and, by its very nature, a high spectral resolution lidar (HSRL). The HSRL aspect of CATS will provide information on cloud and aerosol height, internal structure, and optical properties (e.g., extinction). The Doppler aspect adds capability to derive wind motion, which in turn enables studies of aerosol transport and cloud motion. The technology developed has direct application to future spaceborne missions, such as the proposed Aerosol-Cloud-Ecosystems (ACE) mission, and will provide critical validation capability for future missions.

Designed from the start for operation on high-altitude aircraft, the CATS lidar is primarily intended as a demonstrator for the ACE mission. The ACE mission identifies a lidar instrument to provide cloud/aerosol height and properties. Although the specific type of lidar is not identified (except the desire for cross-track coverage and dual wavelength), our proposed CATS instrument will provide a combination of backscatter lidar, Doppler lidar, and HSRL. Although it is an HSRL, the single-wavelength CATS lidar is designed to enable aerosol transport studies. In addition, the need to point off-nadir for wind measurements inherently enables cross-track cloud/aerosol measurements as desired by the ACE mission.

The CATS lidar will also provide an important technology demonstration for a future global wind system. Global wind measurements from space are recognized as an essential and unfulfilled measurement capability. Although different lidar techniques are being evaluated, no single method is yet mature enough to propose as a definitive space-based system. Because of the numerous difficulties inherent in the measurement it is unknown if any of the methods currently being evaluated will result in either a successful demonstration of wind measurement technology, or in a system that is scalable to space platforms. Demonstration flights of the CATS lidar will permit both science and engineering evaluation of an alternate approach to the measurement.

We are leveraging more than a decade worth of research to demonstrate cloud and aerosol transport measurements using the CATS lidar. The CATS instrument has been developed through a combination of internal Goddard funding, Earth Science Technology Office (ESTO) funding, and leveraging from numerous Small Business Innovative Research (SBIR) investments. The result is an instrument that is available and will be ready for integration to the aircraft in mid-2010.

This proposal seeks support to integrate the CATS instrument to a high-altitude research aircraft and perform initial engineering flights in preparation for routine science and satellite validation use. Operation on the aircraft will provide demonstration of both technology and measurement capability. Having the CATS instrument onboard a high-altitude research aircraft will also enable a critical contribution to future NASA field campaigns. Initially we will fly CATS with our existing Cloud Physics Lidar (CPL) to provide full demonstration of our proposed concept for the ACE lidar (i.e., 3 backscatter wavelengths at nadir with depolarization, and HSRL/Doppler capability off-nadir).

Delwyn Moller / Remote Sensing Solutions
The Airborne Glacier and Land Ice Surface Topography Interferometer (GLISTIN-A)

The estimation of the mass balance of ice sheets and glaciers on Earth is a problem of considerable scientific and societal importance. A key measurement to understanding, monitoring and forecasting these changes is ice-surface topography, both for ice-sheet and glacial regions. As a reflection of this need ICESAT II has been recommended in the first launch window (2010-2013) by the NRC decadal survey. However, while ICESAT II will provide valuable transects of ice-sheet and glacial regions, under-sampling due to the cross-track spacing, particularly in the dynamically complex and topographic glacial areas can lead to volume estimation errors in excess of 50%. A high resolution, high-precision topographic mapping capability is an ideal complement to ICESAT II and other surface topography measurements which have limited coverage and/or resolution.

In response, a swath-mapping airborne sensor on the NASA Gulfstream III recently flew a comprehensive campaign in Greenland as part of the International Polar Year (IPY) activities. A first of its kind, the Ka-band interferometric radar successfully demonstrated ice-surface topography mapping at high resolution for swaths in excess of 6km. The proof-of-concept demonstration was achieved by interfacing Ka-band RF and antenna hardware with the L-band UAVSAR. Following this success, we propose to transition this demonstration to a permanently-available pod-only Ka-band UAVSAR configuration compatible with pressurized and unpressurized operation. Under this proposal, the interferometric antenna panel and modified pod from the IPY will be populated with new Ka-band up and down-converter chains and a state-of-the-art solid-state-power-amplifier to result in 1) more peak transmit power and 2) the ability to "ping-pong". These simple upgrades will greatly enhance the performance beyond that achieved during IPY and make wider-swath and higher altitude operation possible. Ultimately, as UAVSAR is transitioned to flight on the GlobalHawk, GLISTIN-A could provide detailed maps of scientifically significant Antarctic regions that have previously proved too remote for dedicated observations.

Carl Weimer / Ball Aerospace & Technologies Corp
An Advanced Imaging Lidar for Forest Carbon Studies

The Electronically Steerable Flash Lidar (ESFL) is a new type of imaging, full-waveform lidar for advanced three-dimensional imaging of forest scenes. Designed with a technology path-to-space, it utilizes independently steerable multiple beams from a laser combined with a two-dimensional "Flash" focal plane array configured with integrated micro-lens arrays. The combination allows the system to be dynamically reconfigured to match the spatial sampling to the forest scene of interest to maximize science return. The ability to reconfigure the beam pattern while imaging the patterns has a number of advantages. Larger beams can be used to match typical tree crown sizes for a region while simultaneously sub-beam imaging can provide finer detail. The beams can be configured for contiguous sampling as a pushbroom to measure the fine spatial scales of the forest (important for estimates of biodiversity) or spaced apart to give a statistical measurement of the biomass stored in the larger forest. The fine pointing capability can allow precise beam ground tracks to be followed from aircraft or space. Using data from co-boresighted secondary cameras, the beam steering can be used to steer the beams to fall between clouds (when broken), increasing science returns. Since a two-dimensional Flash focal plane array is used, the beams can be configured as either cross-track, along-track, or even a combination where the beam energy can be re-configured at the video rate of the focal plane. ESFL has been built, and flight testing has started, on a NASA Instrument Incubator Program to demonstrate its potential. The proposed effort will extend the performance capabilities of ESFL and prepare it for investigator led aircraft science campaigns. This includes aircraft demonstration work validating its science measurements using traditional forest survey methods, new close-range photogrammetry, and a ground-based lidar.