A method of determining the de-aliased range rate of a target in a horizontal plane by a host vehicle equipped with a
radar system, said
radar system including a
radar sensor unit adapted to receive signals emitted from said host vehicle and reflected by said target, comprising: emitting a radar
signal at a single time-point instance and determining from a plurality (m) of point radar detections measurements therefrom captured from said radar sensor unit, the values for each point detection of,
azimuth and range rate; [θi, {dot over (r)}i]; for each point detection determining a range rate compensated value ({dot over (r)}i,cmp); c) determining a plurality (j) of velocity profile hypotheses; for each (j-th)
hypothesis determining modified compensated
hypothesis range rates ({dot over (r)}i,j,cmp) in respect of each point detection on the target, based on the values of range rate compensated ({dot over (r)}i,cmp); for each j-th
hypothesis, determining values of the longitudinal and lateral components of the range
rate equation of the target {tilde over (c)}t,j and +{tilde over (s)}t,j; for each j-th hypothesis and for each point detection determining a velocity profile estimator range rate ({dot over ({
circumflex over (r)})}i,j,cmp); for each hypothesis, for one or more point detections, determining a measure of the dispersion of, or variation between the velocity profile estimator range rates ({dot over ({
circumflex over (r)})}i,j,cmp) for each velocity profile hypothesis and their respective modified range rates ({dot over ({
circumflex over (r)})}i,j,cmp) from step d), or the dispersion of, or variation between, one or both of the velocity profile components {tilde over (c)}t,j and {tilde over (s)}t,j for each velocity profile hypothesis, and selecting the velocity profile where said measure of dispersion or variation is the lowest; setting the de-aliased range rate as the velocity of the velocity hypothesis selected.