A study of some FMCW radar algorithms for target location at low frequencies

摘要

FMCW (frequency-modulated continuous wave) radar is a simple and inexpensive technique for target location. The resolution is given by the available bandwidth and the directivity of the antenna. Resolution is not a problem at high frequencies, while at low frequencies (the HF and VHF band), and especially for mobile platforms, the required size of the antenna becomes impractical. In order to obtain the bearing of the targets, without relying on directivity, one may use a simple two-dimensional trilateration method that involves several platforms. Since this approach covers an area, rather than a sector, the range is reduced to some tens of kilometers. The VHF band and a bandwidth below 10 MHz is a good choice if the priority is to reduce radio interference. Fast targets, corresponding to a significant Doppler shift, have not been considered. The problem of ghost targets has been studied for both monostatic and multistatic radar. When there is a confluence of echoes, more bandwidth is required to maintain the accuracy of a few meters that is normally obtained in the simulation.