基于高精度星敏感器的船载雷达海上精度鉴定

航天测量船海上航行时主要通过精度校飞进行雷达精度鉴定,针对其周期长、耗费大和组织协调困难的缺点,提出了一种采用高精度星敏感器与雷达捷联跟踪测量空间目标进行海上精度鉴定的方法。雷达在跟踪空间目标的同时,星敏感器实时拍摄天线指向附近星图。首先,星敏感器利用雷达输出的编码器角度计算视轴的初始指向,通过快速星图识别和目标定位获取天线地心坐标系精确指向;然后,经坐标变换到地平系,根据蒙气差模型修正地平系俯仰角,再经过船摇修正转换到甲板坐标系;最后,进行轴系误差及脱靶量修正,实现雷达指向精度鉴定。试验结果表明:利用该方法测量的船载雷达相对于星敏感器方位、俯仰随机残差优于50″,满足雷达精度鉴定要求,证明该方法的可行性。

Maritime precision appraisal for ship-borne radar based on high-precision star sensor

At the time of marine navigation for the astronautic measurement ship,it was mainly subject to radar precision appraisal through accuracy calibration flight;thus it has long period,large costs,hard organization and coordination,and other defects.By taking advantages of high-precision star sensor and radar strap-down to track and measure the space target,a kind of marine precision appraisal method was proposed.At the time of tracking space target by radar,the star sensor shoots the star map nearby the antenna pointing.Firstly,the star sensor calculated the initial pointing of the bore-sight by the angle of the encoder output by radar;through fast star map identification and target localization,the precision pointing of the geocentric coordinates system for the antenna was obtained;Then,it was transformed to the horizontal coordinate system from the coordinate;according to atmospheric refraction model,the pitch angle of the horizontal coordinate system was corrected;and it was transformed to the deck coordinate system through ship swing correction;Finally,the pointing precision evaluation of radar was realized through axial system error and miss distance correction.The experimental result shows that comparing with the star sensor,the azimuth and pitch angle random rest error of the ship-borne radar measured by using the method is superior to 50 ",which meets the requirement of radar precision evaluation and shows the method is feasible.