A new approach to beam Doppler sharpening which allows nonlinear geometries and mapping

Range relative Doppler processing (RRDP) was developed to reduce range walk. Beam Doppler sharpening can be extended to nonlinear geometries using RRDP. The reflectivity information of the Doppler cells can be mapped onto an absolute x-y reflectivity map by including an invariant mapping technique (IMT). Extended beam Doppler sharpening (EBDS) is illustrated by an example. The two main advantages are that it remains valid even for nonlinear geometries where range walk is large and that it includes mapping to combine the information of all the footprints. In the example, the improvement in azimuth resolution over azimuth beamwidth is very significant, except at very low azimuth angles. All the results are in complete agreement with the theory