舰船的混合SAR-ISAR成像研究

Study of Hybric SAR-ISAR Imaging of Ship

运动机载雷达对海面运动舰船目标成像时，由于相对运动的复杂性，直接成像难以达到理想效果。因此必须事先估计两者相对运动变化，对数据段有选择地成像。本文基于图像投影平面原理，分析了机载雷达和舰船目标各自的运动特点，提出了采用子图像多普勒展宽估计雷达与目标相对运动的变化过程，并以此为依据，合理选择观测数据段成像，从而降低了成像难度，提高了成像质量。

Radar imaging of ocean-going ships is a function of both SAR and ISAR imaging techniques. Both the radar and the target are moving so the range-Doppler image formation is not due to either a SAR or ISAR imaging mechanism acting alone, but to contributions from both. In this paper we analysis the motions of radar and the ship based on target image projection plane, and present a method to estimate the relative motion between the radar and the ship by Doppler extension of the sub-images. Images of good quality are required to be from radar data corresponding to the time intervals of smooth change of the Doppler extension. Simulation results are presented which verify this analysis.