The correction of Doppler errors and receiver chain anomalies in CW radars

Abstract

The conventional algorithm often used in coded CW radar processing is summarised and a generic frequency domain equivalent to this algorithm is defined. The algorithm gives the ability to control the correlation function at each Doppler bin, thereby removing the usual losses, and associated increase in sidelobes, caused by the correlation of Doppler targets. Phase coded CW radars can exhibit a number of problems, such that when 'perfect' codes are implemented 'perfect' performance is not realised. The problems are discussed and the approach of smoothing the spectrum over the code bandwidth in order to correct for system losses and interference is presented. Correction of inaccuracies in I and Q channels is demonstrated which reduces frequency images. Real and simulated results show that these techniques improve the resolution of the range Doppler plane by removing noise sources and sidelobes.