Title :
Subspace transformation techniques applied to multi-channel SAR/MTI
Author_Institution :
FGAN-FFM, Wachtberg
Abstract :
Using SAR-systems with several along-track sub-apertures has proven to be a highly sensitive technique for detection and positioning of moving targets. The core of multi-channel SAR/MTI processing is an adaptive filter for clutter suppression. In the SAR environment the processing in the Doppler domain is favourable, since an infinite train of pulses is used. But some problems arise from the large number of degrees of freedom: at the edges of the clutter spectrum the clutter power may be too weak to perform a sufficient adaptation, so that moving target signals are suppressed as well. The objective of this paper is to propose a problem-matched architecture of the clutter adaptation using the technique of “coherent subspace transformation”. This offers stabilisation against rapid flight manoeuvres, coverage of uncertain frequency regions and avoiding the suppression of moving target signals. The proposed processing is illustrated by data gathered with the German “Airborne Experimental Radar” (AER) using four along-track subapertures
Keywords :
adaptive signal processing; airborne radar; geophysical signal processing; geophysical techniques; motion measurement; object detection; radar signal processing; remote sensing by radar; synthetic aperture radar; terrain mapping; Airborne Experimental Radar; SAR; adaptation; adaptive filter; along-track sub-apertures; along-track subaperture; clutter adaptation; clutter power; clutter suppression; coherent subspace transformation; geophysical measurement technique; infinite train of pulses; land surface; moving object detection; moving target; moving target signal; multi-channel SAR MTI; problem-matched architecture; radar detection; radar imaging; radar remote sensing; subspace transformation; synthetic aperture radar; vehicle motion; Adaptive arrays; Adaptive filters; Airborne radar; Apertures; Clutter; Frequency; Random variables; Scattering; Sensor arrays; Sensor phenomena and characterization;
Conference_Titel :
Geoscience and Remote Sensing Symposium, 1999. IGARSS '99 Proceedings. IEEE 1999 International
Conference_Location :
Hamburg
Print_ISBN :
0-7803-5207-6
DOI :
10.1109/IGARSS.1999.773393