Jitter compensation of ZiYuan-3 satellite imagery based on object point coincidence

Abstract

ABSTRACTSatellite jitter is a very important factor that affects the sensor orientation of ZiYuan-3 imagery based on a rational function model (RFM). The conventional affine transformation model is unable to compensate such periodic jitters. The sensor orientation accuracy is thereby worse than expected. To eliminate the influence of jitters and improve the orientation accuracy, a feasible jitter compensation method for ZiYuan-3 imagery based on object point coincidence is presented in this study. In this method, no actual ground control points (AGCPs) are required to estimate the jitter compensation parameters. First, numerous virtual object points are projected onto the image by using the RFM. Then, the residual errors between the image-space coordinates of the projected and corresponding points are used to detect the satellite jitters. Finally, two sinusoidal functions are used to model and compensate the jitters. Experimental results of the three ZiYuan-3 satellite images show that before the jitter compensation, the residual errors of the independent check points obviously show a sinusoidal pattern. These periodic errors cannot be effectively compensated by the affine transformation model even if the number of AGCPs is increased from 4 to 16. After the jitters are compensated with the estimated sinusoidal coefficients, the influence of jitters can be eliminated. The sensor orientation accuracies of the three images reach 0.852 pixels, 0.798 pixels, and 0.921 pixels, which are respectively 49.7%, 55.1%, 65.7% better than those achieved before the jitter compensation.