Doppler compensation in forward-looking STAP radar

For air- and spaceborne MTI radar the clutter Doppler frequency depends on range for all array geometries other than linear sidelooking. This applies particularly to forward-looking arrays. The range dependence of the clutter Doppler causes specific problems in clutter rejection through STAP (space- time adaptive processing) techniques. One aspect is the lack of training da ta required for adapting the STAP filter. Another aspect is that the STAP f ilter becomes range dependent. A technique for compensating for the range d ependence is proposed. The efficiency of the method is verified by use of c lutter data measured with the multichannel radar AER II (airborne experimen tal radar).