A new method for estimating the rotation angle of ISAR image

The estimation of rotation angle is the precondition for ISAR imaging. In this passage, a new method based on the analysis of the echo signals is proposed. The signals in different range bin are approximated as the multi-component third-order polynomial signals, and the proportion of third-order phase coefficient to first-order phase coefficient is constant just equal to the square of the rotation rate. Then the parameters of the third-order polynomial signal are estimated by the maximum likelihood method. The results of real data show the validity of the method proposed.