HR: 14:10h
AN: IN23B-03    [Abstracts]
TI: The Glacier and Ice Sheet Topography Interferometer: An Update on a Unique Sensor for High Accuracy Swath Mapping of Land Ice
AU: * Moller, D
EM: delwyn.moller@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AU: Heavey, B
EM: brandon.heavey@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AU: Hensley, S
EM: scott.hensley@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AU: Hodges, R
EM: richard.hodges@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AU: Rengarajan, S
EM: sembiam.Rengarajan@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AU: Rignot, E
EM: eric.rignot@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AU: Sadowy, G
EM: Gregory.sadowy@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AU: Simard, M
EM: marc.simard@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AU: Zawadzki, M
EM: mark.zawadzki@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109,
AB: We discuss the innovative concept and technology development of a Ka-band (35 GHz) radar for mapping the surface topography of glaciers and ice sheets. The "Glacier and Land Ice Surface Topography Interferometer" (GLISTIN) is a single-pass, single platform interferometric synthetic aperture radar (InSAR) with an 8mm wavelength, which minimizes snow penetration yet remains relatively impervious to atmospheric attenuation. Such a system has the potential for delivering topographic maps at high spatial resolution, high vertical accuracy, independent of cloud cover, with a subseasonal update and would greatly enhance current observational and modeling capabilities of ice mass-balance and glacial retreat. To enable such measurements, a digitally beamformed antenna array is utilized to provide a wide measurement swath at a technologically feasible transmit power. To prove this concept and advance the technology readiness of this design we are currently funded by the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) to build and test a 1m x 1m digitally-beamformed (DBF) Ka-band slotted waveguide antenna with integrated digital receivers. This antenna provides 16 simultaneous receive beams, effectively broadening the swath without reducing receive antenna gain. The implementation of such a large aperture at Ka-band presents many design, manufacturing and calibration challenges which are addressed as part of this IIP. The integrated DBF array will be fielded at the Jet Propulsion Laboratory's antenna range to demonstrate the overall calibration, beamforming and interferometric performance through creation of topographic imagery of the local Arroyo Seco. Currently entering the third year of the program, we will overview the system concept, array implementation and status of the technology. While the IIP addresses the development of the major technology challenges, an additional effort will demonstrate the phenomenology of the measurement by adapting the NASA ESTO-funded Uninhabited Aerial Vehicle - Synthetic Aperture Radar (UAVSAR) system for Ka-band single-pass interferometry. The conversion to Ka-Band will utilize the modular UAVSAR system originally designed for L-Band operation, retaining the radar control, data acquisition and processing infrastructure and requiring only minor pod and RF modifications. We will fly the Ka-Band interferometer aboard the UAVSAR platform over regions of Greenland, flying a grid over Jakobshavn glacier, then a transect from the coast to Swiss Camp ending at Greenland's Summit. Over a period of 4-5 weeks at the beginning of the melt season, these flight missions will be repeated in different snow/ice conditions. The flight data will be compared with airborne laser altimetry (Airborne Topographic Mapper lidar instrument, NASA GSFC/Wallops), field observations (GPS data at Swiss Camp, Summit), and climate data from the Automatic Weather Station (Colorado University) network (snowfall, corrected for densification) to estimate penetration and produce topographic surface maps. Topography is an essential piece of information for glaciology and a high-quality topographic map (tens of cm height accuracy over 10m pixels) will be produced. The experiment will pave the way to making more topographic products available to glaciologists and aid in the design a spaceborne mission capable of delivering similar products at the continental scale.
DE: 0720 Glaciers
DE: 0726 Ice sheets
DE: 0758 Remote sensing
DE: 0762 Mass balance (1218, 1223)
SC: Earth and Space Science Informatics [IN]
MN: 2007 Fall Meeting