基于高频角位移数据的卫星平台颤振检测与影像几何质量补偿

Satellite Platform Jitter Detection and Image Geometric Quality Compensation Based on High-frequency Angular Displacement Data

随着对地观测卫星成像分辨率和在轨机动性能的提升,卫星平台姿态的高频颤振对成像几何质量的影响更加显著。鉴于传统的基于分时成像数据的颤振检测和补偿方法具有密集匹配计算量大,误差干扰程度高和无法分解各旋角方向的颤振量等缺点。该文以国产遥感系列光学卫星搭载的高频角位移设备为例,研究基于角位移高频测姿数据的直接颤振检测方法和影像几何质量补偿方法。其中包括角位移数据的加窗FIR滤波预处理,在俯仰、翻滚和偏航方向随时间变化的颤振曲线分布规律分析,以及基于角位移数据的影像直接定位补偿。将高频颤振补偿应用于卫星平台的姿态复原和基于严格成像几何模型的几何纠正解算。采用北京地区遥感系列光学卫星数据的实验结果表明,该文方法能够显著地改善高频颤振检测的精度和可靠性,有效地提高颤振补偿后卫星影像的内部几何质量,其中长度变形精度提高了0.5个像素左右。

With the improvement of imaging resolution and on-orbit mobility of earth observation satellites, the imaging geometric quality is more apparently influenced by the attitude＇s high-frequency jittering of satellite platform. The traditional time-division imaging data based jitter detection and compensation methods have many drawbacks, which include large amount of calculation and high degree of error interference in dense matching, and it is unable to decompose the jitter quantity in each rotation angle direction. This paper takes the high-frequency angular displacement equipment which is carried by China＇s remote sensing optical satellite for example, studies on the direct jitter detection method and the image geometric quality compensation method based on high-frequency attitude measurement angular displacement data, which include the windowed FIR filter pre-processing of angular displacement data, the phase distribution analysis on time-dependent jitter curve in pitch, roll and yaw directions, as well as image direct positioning compensation based on angular displacement data. The high-frequency jitter compensation is applied to attitude recovery and geometric rectification based on strict imaging geometric model.The experimental results of China＇ remote sensing satellite images in Beijing area illustrate that the methods proposed in this paper can significantly improve the accuracy and reliability of the high- frequency jitter detection, and can effectively improve the internal geometric quality of satellite image after jitter compensation. For example, the length deformation accuracy can be improved by 0.5 pixel.