Rotation Estimation for ISAR Targets With a Space–Time Analysis Technique

A new method for estimating the rotational motion of a noncooperative target is presented by exploiting the 2-D space-variant characteristic of inverse synthetic aperture radar imaging. With a space-time analysis technique, the position variation of every extracted scattering center in both the range and cross-range directions can be utilized for rotation estimation. This method differs substantially from conventional methods that exploit high-order terms of the Doppler frequency, i.e., only the position variation in the cross-range direction. An iterative processing scheme is proposed to extract as many scattering centers as possible from the phase history of returned echoes. Experimental results with some measured airplane data demonstrate the effectiveness of the proposed method.