Interferometric inverse synthetic aperture ladar target detection method.

Abstract

To improve the target detection performance of inverse synthetic aperture ladar (ISAL) under the situation that there is Doppler bandwidth ambiguity, we consider energy accumulation of echo signals along a range through matched illumination. However, since the target impulse responses change with the target aspect angle, the phase shifts along slow-time between range cells are different, and the output of matched illumination fluctuates along slow-time. To reduce the slow-time fluctuation of matched illumination under additive white Gaussian noise assumption, we have proposed an interferometric ISAL (InISAL) target detection method based on interferometry processing and principal component analysis (PCA) in this paper. After the interferometry processing, the interferometric phase shifts along slow-time of all range cells are approximately the same. Then PCA is introduced to reduce the impact of noise, interference, and cross-terms of interferometry processing. Thus, the slow-time fluctuation of matched illumination can be decreased, and the target detection performance is improved. The proposed method has been validated with both simulated data of InISAL and real data of millimeter-wave interferometric synthetic aperture radar.