Solid State Fractional Phased Array Addition To NWRT

The National Weather Radar Testbed (NWRT) serves as a tool for radar meteorological research and for investigation of techniques for utilizing phased array radars for weather sensing. Using a SPY-1A phased array antenna, loaned to NOAA by the U. S. Navy, the testbed is capable of performing scans over user-defined sectors considerably faster than conventional weather radars using rotating reflector antennas. Lockheed Martin and NSSL are planning an addition to the NWRT in the form of a solid state transmit/receive (T/R) module fractional array. This array will provide a proof of concept capability for advanced phased array applications to meteorological sensing and multifunction applications. In particular, implementation will support validation of concepts such as dual polarization control and calibration over all scan angles, digital beamforming, beam multiplexing, site specific nulling of point clutter, split array processing for wind direction estimation and real time dwell scheduling to support adaptive scan algorithms. In this paper we provide an overview of the proposed fractional array capabilities, integration with NWRT and some of the radar design tradeoffs that may be required as the project proceeds.