Synthetic aperture radar (SAR) is becoming increasingly important in many military ground surveillance and targeting roles because of its ability to operate in all weather, day and night, and to detect, classify and geolocate objects at long stand-off ranges. Bistatic SAR, where the transmitter and receiver are on separate platforms, is seen as a potential means of countering vulnerability. This paper provides an overview of QinetiQ's on-going research into the processing techniques for bistatic SAR, the fundamental problems it introduces, and ways to overcome them.