13 A . 5 A New Method for Compressing Quality-Controlled Weather Radar Data by Exploiting Blankout Markers Due to Thresholding Operations

A meteorological radar data assimilation system has been developed at the Marine Meteorology Division of the Naval Research Laboratory (NRL) to provide environmental information to enhance the safety of ship and aircraft operations. Radar observations are assimilated into the Navy’s Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) to improve the forecasts of hazardous weather (Zhao et al. 2006; 2008) and to provide decision makers with timely products to help exploit or mitigate those predictions. The system will take advantage of a selected group of Navy ships that are to have weather processors installed for their tactical radars (e.g., SPS-48E/G: Hazardous Weather Detection and Display Capability (HWDDC); SPY-1 Tactical Environmental Processor). This group of ships will be able to digitally generate fullresolution, volumetric weather radar data every minute, and also archive them to Universal Format (UF) files (Barnes 1980). There are plans to transmit three UF files per hour in near-real-time to Fleet Numerical Meteorology and Oceanography Center (FNMOC) where the data assimilation into COAMPS is conducted. UF file sizes range from ~5 MB (SPS-48E) to ~13 MB (SPY-1), which would be too large a load on the operational bandwidth of the ships’ communication systems. To overcome this obstacle, we have developed a novel UF file compressor that typically reduces UF file sizes by a factor of forty, thus permitting their transmission from a ship to FNMOC (Pan et al. 2009). NRL has delivered the UF file compressor to Basic Commerce and Industries, Moorestown, NJ, who is the developer of the HWDDC under contract for Space and Naval Warfare Systems Command (SPAWAR) Systems Center, Pacific, San Diego, CA. From May to August 2009, BCI and SPAWAR conducted tests using the land-based SPS-48E at Navy