Characterizing Beat Terrain Fluctuations in Ranging the Leaky Sensor of FMCW Transceiver

In FMCW based leaky sensor application, a static filed being always returned as beats, develops a ranging profile, even in the absence of an intrusion. The constant presence of beats and their environment dependent gain fluctuations impose great challenge in detection of a potential threat. This paper proposes a methodology to detect the presence of an intruder by adaptively analyzing the probability distribution profile of each range bin, suppressing the ranging clutter and identifying the true intrusion zone. The algorithm adapts to a detection baseline to discriminate the human intruder from trees, grass and other environment variable as rain, wind etc. The developed scheme is realized on NI-transceiver card, VSG and leaky sensor cable. It is observed that the beat gain fluctuations are highly depended on chosen integration length, leaky sensor separation and received clutter power. The algorithm performance is evaluated through simulations and NI-equipment based field deployment. It is concluded that the proposed method effectively adapts to the leaky sensor’s environment and settles the intrusion detection profile among glitches and environment fluctuations. It is field tested over 100m range.