A Passive Multi-Static Radar Imaging System for Intruding Object Detection

Abstract

A Passive Multi-Static Radar Imaging System (PMSRIS) has been implemented for border surveillance, employing commercial Wi-Fi radios at 5GHz band. The radar array includes two transmitters and four receivers employing commercial Wi-Fi Radios. The radios were set at 5 GHz band at channel 42, and the frequency was selected between 5170 MHz and 5250 MHz. A sampling rate of 1 ms with a bandwidth of 40 MHz was considered in the receivers.  The scanning detected targets were a human and a car. Firstly, some measurements were taken with no target in the area, then the changes in the signals were measured after a person and a car entered the area. An image reconstruction method has been developed based on the Synthetic Aperture Interferometric Radiometer (SAIR), obtains brightness temperature (BT) images by measuring the object’s natural radiation in the microwave band. The proposed method employs a compact Variable Fiber Delay Line (VFDL) as the passive coding technique to encode the signal received by the antenna array. The BT image is reconstructed by decoding the coded signal and using the Fourier transform method. This method is capable of quickly detecting and imaging targets entering the area near land borders. The novelty of this project research includes implementing a new setup for the hardware of system and a new method for SAR image formation method to achieve higher-resolution images. The new MSRIS could be utilized for intruding target detection and border surveillance.