Micro-Doppler and vibrometry measurements require coherent radars with low phase noise. We report the development of a novel, very low phase noise 94 GHz radar, called T-220, which offers superior performance for micro-Doppler and vibrometry studies compared with our previous work. The radar uses a combination of direct digital synthesis (DDS) chirp generation, frequency upconversion and frequency multiplication to yield very low phase noise and rapid, contiguous chirps, necessary for Doppler studies and other coherent processing applications. Dual fan beam antennas are used to achieve negligible transmit-receive leakage, with fine azimuth resolution and modest elevation coverage. The resulting PPI imagery is very high fidelity with little or no evidence of phase noise effects.
A 94GHz imaging radar with its associated gimbals for stabilisation and scanning has been developed as an airborne test-bed to evaluate radar aided navigation and guidance algorithms. Preliminary results from helicopter based flight tests show sufficient contrast between selected features (including runways) and their surroundings for both computer and human pilot based guidance. Feature extraction and matching algorithms have shown this system to be more accurate than that that achieved by GPS.