Analysis of inner-pulse Doppler effect for the echoes of inverse synthetic aperture LADAR

Inverse synthetic aperture LED AR is an active imaging system, which can achieve high resolution real time imaging for moving targets. For the traditional inverse synthetic aperture radar, the inner-pulse Doppler frequency will reduce the quality of image obviously only when the target has high speed. However, due to the ultra-high frequency and ultra-wide bandwidth of the laser signal, the influence of inner-pulse Doppler cannot be ignored even for the low speed moving targets in the ISAL. This paper analyzes the inner-pulse Doppler effect of the ISAL echoes and presents an echo model for the ISAL. Via the conventional motion compensation method, in which the accurate estimation of reference point´s track is obtained after range realigning and phase focusing, the inner-pulse Doppler effect can be removed and then the image of target can be achieved. Finally, some simulation results are given in the paper.