Ground Clutter Mitigation and Insect Signature Detection for Polarimetric C-Band Doppler Weather Radar

Weather radar returns can come from meteorological targets as well as non-meteorological targets. In general, radar echoes in clear air are caused by insects, dust, birds, and other particles large enough to return some power to the radar. Ground clutter, on the other hand, is a significant source of contamination for weather radar data and can prevent the extraction of relatively weak clear air echoes from insects, for example. To mitigate ground clutter contamination, this work demonstrates a Ground Clutter Mitigation Decision (GCMD) and scan strategy using topographic information from a digital elevation model (DEM) to determine beam blockage. The radar coverage area is classified into three categories: regions that are fully blocked, partially blocked, and unblocked. These regions are used to validate the GCMD algorithm and output clutter map pattern. With clutter mitigation, the potential for the Meteo Rwanda Polarimetric weather radar to detect and monitor insect signatures is discussed through analysis of polarimetric parameters (Z, ZDR and ρHY) for clear area daytime case studies. Insect signatures are postulated for observations collected by Meteo Rwanda C-Band Polarimetric weather radar on 26–27 March 2021 after sunrise.