Direct Cartesian localization in passive MIMO radar networks

This paper considers target localization in passive multiple-input multiple-output (MIMO) radar sensor networks comprised of multiple non-cooperative transmitters and multiple multichannel receivers. The maximum likelihood estimator is derived for direct estimation of target position and velocity in Cartesian space using all measurement data. Localization performance is shown to vary significantly as a function of both target-path SNR and direct-path SNR. In addition to angle information, this estimator is shown to make use of bistatic range, bistatic Doppler, time-difference-of-arrival, and frequency-difference-of-arrival information to varying degrees depending on the target-path and direct-path SNR regime.