Mixed triangulation/trilateration technique for emitter location

The so-called `ghost¿¿ problem which complicates emitter location by triangulation can be circumvented by a mixed triangulation/trilateration technique. The ambiguities in either the spatial or time/frequency domain can be removed by the combined measurement of time difference of arrival (DTOA) and direction of arrival (DOA). The paper describes the concept of a mixed triangulation/trilateration emitter location system which is being implemented at the Siemens company as an experimental set-up. The location performance in terms of location probability, signal/noise power ratio at the correlator output and measurement error is presented.