Airborne antenna array calibration with signals of opportunity

An approach is presented for in-situ calibration of an airborne antenna array using a signal of opportunity. In-situ calibration requires determining location of the unknown signal, the array´s response in the direction of the signal, and the application of updates to the stored antenna response. An example is given in which the approach significantly reduces the mismatch between a true antenna array response and an assumed antenna array response.