Key Technique Research On Perimeter Surveillance Radar Based On FMCW

With the development of society, the need of perimeter surveillance grows day by day. Perimeter surveillance radar is paid great attention due to its wide application of anti-terrorism, reef defence, airport surveillance and so on.Throughout the present state of art, frequency modulation continuous waveform(FMCW) is chosen in this thesis. According to the characteristic of perimeter surveillance radar, a radar system structure is designed, whose local oscillator is independent of transmitter. On the basis of the system structure, slow moving target under background clutter detection algorithm is analyzied. Due to the blind velocity of MTI algorithm, a perimeter intursion synthesis detect algorithm is proposed to detect intrusion target in the wide range of velocity. A prototype system of perimeter surveillance radar is designed to verify the algorithm. The main work inculdes:1. Derive normalized ambiguity function of linear frequency modulation continuous waveform(LFMCW) in terms of matched filter recevier, analyze the inherent resolution of target. Design radar system whose local oscillator is independent of transmitter, and analyse the signal processing technique. The ’range-doppler’ coupling phenomenon is explained in terms of signal processing, and finalize symmetry triangle linear frequency modulation waveform(ST-LFMCW) to be the transmit signal of perimeter surveillance radar.2. Due to detection of target with slow intrusion velocity under background clutter, multi-period ST-LFMCW inter-frequency echo is modeled, combined with moving target indication(MTI) and 2 dimension-fast fourier transform(2D-FFT) technique, slow moving target detect algorithm is analyzied. Algorithm performance is studied from the aspects of target resolution, accumulation gain, signal clutter ratio improvement, minimum detectable velocity and blind velocity. The effect of the algorithm is verified through computer simulation, which surpports system parameter design.3. Due to the blind velocity of MTI+2D-FFT algorithm, frequency domain cancelling(FDC) algorithm is studied, on the basis of which a synthesis intrusion detect algorithm is proposed, overcoming the blind velocity of MTI algorithm. The proposed algorithm is able to detect intrusion target in the wide range of velocity. Algorithm performance is analyzied in terms of target resolution, accumulaion gain, signal clutter ratio improvement and detectable velocity range. Computer simulaion result demonstrates the effect of the algorithm.4. Develop the prototype system of perimeter surveillance radar. Use the verified system parameter to design the system plan, and the timing logic of radar controller is analyzied and simulated. On the top of that, out-field experiment is carried out to verify the proposed synthesis intrusion detect algorithm, proving that the algorithm can detect intrusion target in the wide range of velocity.