A radar processor for processing a frame of radar data received from one or more targets, the frame of radar data having a carrier frequency and comprising a sequence of codewords with a codeword repetition interval, wherein the carrier frequency and the codeword repetition interval define an unambiguous velocity range, the radar processor configured to: receive the frame of radar data; transform the frame to obtain a velocity data array; apply a correction algorithm to the velocity data array to correct a Doppler shift of the frame to obtain a corrected array, wherein the correction algorithm comprises a set of Doppler correction frequencies corresponding to a set of velocity gates and at least one of the set of Doppler correction frequencies corresponds to a velocity gate outside the unambiguous velocity range; and perform range processing on the corrected array to obtain a range-Doppler map.