Compression strategies for super resolution WSR-88D radar data

Weather radar products retrieved from the National Weather Service are used by both the government and the private sector. In recent years radar data has been increasingly collected in real time for use by end users. However, the bandwidth needed to transmit the information from the radar to the destination site is a limiting issue. General purpose compression programs are not tuned to the properties of weather radar data and are intended for compressing large blocks of general data. In future software releases, the National Weather Service will be increasing the size of the weather radar data, and compression is of vital interest to keep maintenance, storage, and transmission costs down. A method for lossless compression of this data on a radial-by-radial basis focusing on the delta between range bins on super resolution radar data is developed. This method is called Super Delta compression because of its focus of calculating the delta (difference) on super resolution radar data. There are several specialized aspects of Super Delta that are based on the properties of the weather radar data. This method is tested on Level II reflectivity product data from S-band Doppler weather radars, and is compared with two general purpose compression programs and a custom compression scheme. The results show that Super Delta compression yield is close to 15% above the next best scheme and about 47% better than the uncompressed radials. Other schemes for compression are proposed for future work.