Patent ID: 7190302

Claim:
Radar imaging apparatus comprising a transceiver including a single transmit antenna and at least one separate receive antenna, control means for operating the transmit antenna in a stepped frequency continuous wave mode, scanning means for mechanically scanning said transceiver across a surface of interest, position providing means providing a position signal indicative of the instantaneous position of the transceiver, signal analysing means for analysing amplitude and phase components of the receive antenna signal, and signal combining means for combining the output of said signal analysing means with said position signal as in a synthetic aperture array to provide a radar image signal of the surface and underlying features, characterised in that (a) the apparatus is arranged for operation over a bandwidth of at least 8 GHz; and (b) part of the scanning means in use is located at a fixed position relative to said surface and the position providing means is arranged to provide a position signal as a function of the instantaneous position of the transceiver relative to the said fixed position.