Experimental MTI with spaceborne geometries

Airborne or spaceborne surveillance radars provide powerful tools for addressing a variety of ground surveillance activities from terrain height mapping to moving target detection. This range of different activities may in principle all be performed by a single radar system designed to operate in a variety of different modes. Whilst the concept of operating in different modes on a common radar is straightforward the implementation and optimisation of the overall design is not. The research presented here deals with the addition of a GMTI (ground moving target indication) mode onto a SAR ground imaging radar. The two conflicting design requirements can be dealt with using multiple along-track beams: a horizontal interferometric configuration. This allows the GMTI mode to operate in a manner that will allow acceptable moving target detection performance to be recovered from a sideways-looking SAR system. The interferometric multi-beam configuration enables space-time adaptive processing (STAP) solutions to be applied in order to differentiate between unwanted static clutter and slowly moving targets of interest