NEXRAD Product Improvement—Update 2009

The NEXRAD tri-agencies (Department of Commerce, National Weather Service; the Department of Defense, Air Force Weather Agency; the Department of Transportation, Federal Aviation Administration) have established the NEXRAD Product Improvement (NPI) Program as a long-term activity to steadily improve WSR-88D science and technology. New algorithms and technology continue to be fielded on the open systems Radar Product Generator (RPG) and open systems Radar Data Acquisition (RDA). In 2007, Sachidananda-Zrnic SZ-2 phase coding was deployed and has seen widespread use to recover Doppler data from range folded areas. Also, finer spatial resolution base data (Super Resolution) and longer range Doppler data processing (to 300 km) were deployed in the spring of 2008, and have provided greatly improved depiction of rotation couplets for tornado potential analysis. The NPI program is now in the midst of a project to implement dual polarization throughout the WSR-88D network, which will vastly improve rainfall estimates, hydrometeor classification and overall data quality.

In addition to WSR-88D efforts, NPI is working to integrate weather data from several FAA radar systems into NWS operational use. Data connections have been established between WFOs and all 45 Terminal Doppler Weather Radar (TDWR) units to provide expanded low altitude coverage and enhanced WSR-88D back-up operations. On the horizon are potential projects for short wavelength, boundary layer radars to improve low altitude tornado detection and to support storm scale NWP models. A bit further out is the potential for incorporation of Phased Array Antenna technology, with its promise of comprehensive, rapid scanning surveillance.

This paper updates the status of NPI projects, describes recent science and technology enhancements to the WSR-88D, and explores the expanding opportunities for development and implementation of new radar science and techniques intended to use WSR-88D and FAA weather radar data.