Using Sidelobe Cancellation to Mitigate Ground Clutter on the National Weather Radar Testbed

The National Weather Radar Testbed (NWRT) Phased Array Radar (PAR) provides a unique opportunity to study sidelobe cancellation for mitigating ground clutter. An important component of the PAR is an eight-channel receiver, a collaborative project between the OU Advanced Radar Research Center and the National Severe Storms Laboratory that allows the archiving of multiple channels of time series data. This receiver is connected to the main phased array antenna and six receive-only apertures that surround it; the signals from the sum channel and the sidelobe channels can then be combined to spatially filter ground clutter. Special collection techniques such as surveillance scanning and beam multiplexing utilize a small number of pulses which are not sufficient for traditional time or frequency domain ground clutter filtering. Spatial clutter filtering is an alternative that may allow for significant clutter suppression in these challenging cases. By adapting methods used to mitigate clutter on wind profiling radars, the NWRT PAR can act as a proof-of-concept for these techniques that could later be extended to more capable active array antennas. In this paper, preliminary results will be shared that show the performance of these sidelobe cancellation algorithms on collected time series data.