Moving Target Localization for Indoor Imaging using Dual Frequency CW Radars

In this paper, we propose a simple method, to determine the unambiguous range of a moving target, using dual frequency continuous wave (CW) radars. The carrier frequencies, and hence the wavelength, determine the maximum unambiguous range of the target. The technique is capable of determining range for an indoor moving target. It uses phase comparison of the Doppler signals to estimate the range, where as the target velocity is directly obtained from the Doppler shift. Simulation results are presented in the presence of noise to validate the technique. Experimental results are also provided showing the effectiveness of the proposed method for indoor range estimation. Specifically, we have performed two experiments, the first experiment is in an indoor laboratory setting with absorbers to mitigate multipath. In the second experiment, the target was behind a one foot thick concrete wall, in an indoor setting without absorbers. For both experiments, we were able to successfully detect the target and estimate its range