The Human Body Detection Algorithm Based On Radar Echo Research

Non-contact detection to the human body has extremely important significance in the field of disaster relief,medical monitoring,modern warfare and terrorism. The breathing,heartbeat and walking will modulate the electromagnetic waves emitted by the radar and bring the Doppler effect. The purpose of detection and extraction of the characteristics of human motion can be achieved by processing the doppler information. But there are many issues to be resolved.For example:the signal to noise ratio is very low and harmonics need to be suppressed when detecting the breathing and heartbeat. The resolution is low when making time-frequency analysis on the human gait signal.Attentions are paid to the vital signs and the human gait signal. Researches are focused on improving the signal to noise ratio,inhibiting harmonics of vital signs and improving the resolution of time-frequency analysis and other aspects. The main contents are as follows:1. For the signal to noise ratio is very low when detecting the vital signs, the matching transform is proposed. This method can compensate echo phase information, achieve coherent accumulation and improve the signal to noise ratio. The shortcoming of the algorithm is given which explain the algorithm being ineffective;2. For the harmonics of vital signs are many, the algorithm based on high order cumulant about detecting vital signs is proposed. The algorithm can effectively suppress harmonics and improve the signal to noise ratio. The detection performances of the algorithm under different noise background are given;3. For the resolution is low when making time-frequency analysis on the human gait signal, the doppler spectrogram analysis of human gait via iterative adaptive approach is proposed. The algorithm can effectively improve the resolution when making time-frequency analysis. At the same time, the model-order select tool is used in the method,which can show the spectrum more clearly.