Processing Direct Broadcast Data to Reduce Latency of Aqua AMSR-E Products

TitleProcessing Direct Broadcast Data to Reduce Latency of Aqua AMSR-E Products
Publication TypeConference Paper
Year of Publication2011
AuthorsRegner, K, Conover, H, Beaumont, B, Teague, M, Graves, S, Hardin, D
Conference NameAGU
Date Published12/2011
Conference LocationSan Francisco, CA
KeywordsLANCE AMSR-E near real time direct broadcast
AbstractStandard data products from NASA’s Advanced Microwave Scanning Radiometer for Earth Observing Systems (AMSR-E) have served the climate research community well since the launch of the Aqua satellite in 2002. But the time from observation until swath products are made available to end users (approximately 12-15 hours after observation) diminishes their usefulness to such disciplines as weather prediction and nowcasting, natural hazards monitoring, disaster relief, and agricultural monitoring. To address the needs of these communities, NASA’s Earth Science Division built the Land Atmosphere Near-real-time Capability for EOS (Earth Observing Systems), or LANCE, which generates products from several instruments, including AMSR-E, flying aboard the Aqua, Aura and Terra satellites. As for the standard products, the raw satellite data is transmitted from satellite to the EOS Data and Operations System (EDOS), via ground stations in Alaska and Norway, for distribution to the processing elements. The LANCE AMSR-E system generates a variety of Level-2 swath products using essentially the same science algorithms as are used for the standard science products, but with predictive rather than definitive ephemeris. The average latency for these LANCE AMSR-E swath products is approximately three hours from observation; most of this latency is due to the wait time for the on-board recorder to transmit data to the ground. One of the recommendations arising from the first meeting of the LANCE User Working Group was for the data centers to investigate the feasibility of processing direct broadcast data. Since direct broadcast data is transmitted directly from the satellite to the ground and attainable by anyone with ground receiving equipment and in direct line of sight to the satellite, the wait time associated with ground station contacts is eliminated, thereby significantly reducing latency for these datasets. However, direct broadcast data provide limited geographic coverage, in contrast to the global coverage available from the LANCE products. This presentation will describe recent efforts at the AMSR-E data processing center to reduce data latency and also provide a comparative assessment of the three types of AMSR-E products.