A vehicle-based method of determining the extent to which a target object is a single scatterer, said vehicle including a radar system including a radar transmit element, adapted to send a radar signal towards said target object, and an antenna receive array comprising a plurality M of a receive elements, providing a corresponding plurality of N radar receive channels, and adapted to receive radar signals reflected from said target object, said method comprising: a) transmitting a radar signal from said radar transmit element to said target object; b) receiving the reflected signal of the signal transmitted in step a) from the target object at said plurality of receiver elements; c) for each antenna element or channel, processing the received signal to provide amplitude or power data in the frequency domain; d) with respect to the data in step c), for each receive element/channel, determining the frequency with the maximum amplitude or power; e) determining the degree of variability of the results of step d) with respect to each receive element/channel; f) determining the extent to which the target object is a single scatterer based on the result of step e).