RF emitter location estimation in the presence of antenna array manifold mismatch

There is an increasing demand for RF emitter geolocation capability using airborne antenna arrays. However, when an antenna array is mounted on an aircraft, scattering from the aircraft structure significantly affects the array´s magnitude and phase response, which is known as the array manifold. Accurate knowledge of the array manifold is required for angle of arrival estimation. Thus, the derived emitter location estimates will have significant uncertainty unless the user performs a time consuming and costly in-situ calibration of the array. We consider the task of estimating emitter locations when the in-situ manifold is only approximately known. We show that, over a short flight, the errors induced by such `manifold mismatch´ are unbiased and that the true emitter location can be found accurately by considering many measurements at once.