12b.3 Software and Signal Processing Upgrades for the National Weather Radar Testbed Phased-array Radar

The U.S. Government operates seven distinct radar networks providing weather and aircraft surveillance for public weather services, air traffic control, and homeland defense. A next-generation, multifunction phased array radar (MPAR) concept has been proposed that could provide enhanced weather and aircraft surveillance services with potentially lower life-cycle costs than multiple single-function radar networks. If critical technology costs decrease sufficiently, MPAR radars might prove to be a cost-effective alternative to current surveillance radars, since the number of required radars would be reduced, and maintenance and logistics infrastructure would be consolidated. The National Weather Radar Testbed PhasedArray Radar (NWRT PAR) is an S-band (9.38 cm), agile-beam, phased-array radar located in Norman, Oklahoma that was established to demonstrate the MPAR concept (Zrnić et al. 2007). Since its inception in 2003, a team of scientists and engineers at the National Severe Storms Laboratory (NSSL) has enhanced the functionality of the NWRT PAR to bring it up to operational weather radar standards (such as those in the operational NEXRAD network) and, more importantly, to demonstrate new capabilities (Forsyth et al. 2011). Unlike conventional radars, which are constrained by inertial limitations of mechanical scanning, the NWRT PAR can exploit electronic beam steering to focus weather observations solely on areas of interest without having to collect data contiguously. This capability coupled with advanced signal processing, allows for adaptive algorithms to produce higher temporal resolution data without sacrificing quality or spatial resolution through more efficient use of radar resources. This paper focuses on the software and signal processing upgrades aimed at improving the scan control capabilities of the NWRT PAR by enabling the implementation of evolutionary scanning strategies that suit this unique instrument.