Clutter Mitigation Techniques For Doppler Weather Radar For Fine Grain Velocity Estimation

Weather Radars provide valuable information on various weather phenomenon such as rain, hail, storm, etc that are increasingly become important in today’s scenario where disaster management has got a wider role to play. But due to the way a radar works, not only precipitation but also unwanted echoes ,that we broadly classify as clutter , which includes returns from land, sea waves, birds, insects, buildings, etc, is observed by the radar. Such cluttered returns interfere with weather products estimation. Clutter detection and mitigation play a massive role in ensuring accurate weather estimation. In this paper we present two different clutter filtering approaches viz, 1) Time domainIIR Filtering Approach and 2)Frequency DomainFFT spectral processing Approach. Their feasibility in fine grain velocity estimation is discussed and a novel technique for further improvements in Clutter Filtering Approach is suggested. We shall also discuss the loss of velocity information in certain Doppler bands experienced by other clutter filtering techniques and a solution is proposed for the same. key words: doppler weather radar,clutter,FFT,IIR