Aerospace Conducts Radar Observations in Support of Mission Assurance for Soil Moisture Active Passive (SMAP) SpacecraftCorporate Staff
posted November 30, 2012
JPL conducted interferometric radar observations of the south polar region of the moon in September and December 2006 using the Goldstone Lake Bed transmitting and receiving system in the Mojave Desert of California. The Goldstone Solar System Radar observations are formed by transmission of a 16.4 ms 500 kW pulse coded waveform and center wavelength at 2.5 cm using a 70 meter transmitting antenna (DSS 14); and reception at two separated 34 meter antennas (DSS 13 and 25). The intrinsic range resolution for these experiments was 18.75 meters. The footprint of the 70-meter transmitting antenna is approximately 231,000 square km. The duration of observation is approximately an hour. Data products consist in (a) SAR images and (b) interometric lunar topographic maps.
Aerospace-developed radar signal processing image formation algorithms were used to process Goldstone radar data and retrieve high-resolution topographic maps of the lunar surface. This was part of a JPL-funded effort to use the high power Goldstone radar for detailed investigations of the lunar southern pole. In November 2009, Aerospace sent JPL updated and improved image formation software that can resolve features four meters in range and eight meters in cross-range. This efficient image formation software is much faster, and was able to process approximately 130,000 data sets during a 45-minute radar observation campaign. The image formation software, originally developed for Air Force customers, was enhanced to include improved autofocus algorithms, which are more accurate, much more efficient, and can vary the image focus based on variations in terrain elevation. NASA would like to achieve 4-meter cross-range resolution for the topographic radar maps which will require longer duration radar observations. Aerospace is also continuing its work on improving the signal-processing capability. This mapping project for JPL has provided Aerospace the opportunity to improve tools (both software and computer infrastructure) and image processing algorithms that will benefit all users of this technology.