Measuring traveled distance using doppler radar sensors

The purpose of this master´s thesis is to explore the possibility of using Doppler radar modules in acquiring the position of an antenna head. The antenna is a part of the HUMUS man-carried mine detection system developed at the FOI, Swedish Defence Research Agency. The thesis consists of two parts. First there is a thorough presentation of the theory on Doppler radar, spectral estimation and position estimation. The second part is a presentation of the results from evaluating the method on measured data from a test setup. The procedure of estimating the traveled distance, starting from the sampled data, consists of several steps. First the data needs to be filtered to remove any DC-offset and high frequency noise. Second, the power spectrum density of the signal is estimated, using any of the methods presented in the theory part. The third step is to find the Doppler shift frequency from the spectral estimation. Finally the traveled distance (and thus the position) is estimated by integrating the Doppler frequency with respect to time. When testing and evaluating the methods the radar modules was mounted on a test rig and moved a certain distance. The acquired data was then processed in the manner explained above. The result was compared by means of the variance of the estimated distance. On average, the "best" methods produce a result differing approximately 5 % from the real traveled distance.