Multi-channel conversion of the National Weather Radar Testbed receiver

The National Weather Radar Testbed (NWRT) system is based on WSR-88D technology enhanced with the significant capability of a phased array antenna. The agile beam capability provides a unique and powerful tool to focus weather radar asset on observation of severe weather phenomena including structures that lead to formation of these storms. The NWRT system has demonstrated the ability to provide weather data consistent with that from adjacent WSR systems at greatly reduced volume coverage time. Significant success has been reported in use of this tool for gathering and presenting specific, real-time storm-cell 3D data to weather scientists and meteorologists for in-depth interpretation of these pencil-beam radar returns. Specific extensions to the conventional weather radar capabilities now in place include beam multiplexing (spatial filtering), oversampling and whitening (signal processing) and transverse wind estimation (multi-beam). The latter capability has recently been added by activating the difference beam channels of the array and sequentially sampling and comparing these with the conventional sum-only mode. Under the auspices of a National Science Foundation, Major Research Instrument (NSF/MRI) grant, and in cooperation with the United States Navy, the NWRT is now being extended with an 8-channel digital receiver for simultaneous processing of sum, difference and ancillary beam returns. Expectations are high that application of multi-beam adaptation algorithms and other signal processing techniques using multiple channels will lead to improved detection and storm queuing techniques to greatly extend the forecast lead time for severe storms. Multi-channel capability also opens the NWRT for the possibility of testing multi-function radar system algorithms and operations. This paper will describe the attributes of the COTS, rf-system extensions and the specific steps being taken to baseline these changes to the current NWRT system performance.