1. A method of controlling a radar system, the method comprising: a. receiving a radar return signal from a target and generating a range-Doppler target image signature of the target; b. selecting a spectral line within the range-Doppler target image signature from a modulation feature on the target which comprises an effective point scatterer; c. providing a range profile for the spectral line; d. obtaining a reference range profile of a reference point scatterer; e. determining a difference between a power at a range shorter than a peak corresponding to the modulation feature in the range profile and a power at a corresponding range of the reference range profile; f. determining whether the difference is above a threshold value; and g. where the difference is not above the threshold value, generating a first control signal arranged to cause provision of the range-Doppler target image signature, and, where the difference is above the threshold value, generating a second control signal arranged to prevent provision of the range-Doppler target image signature.