Attitude Jitter Detection Based on Remotely Sensed Images and Dense Ground Controls: A Case Study for Chinese ZY-3 Satellite

摘要

Satellite platform vibration induced by the onboard dynamic components and exterior perturbation deteriorates platform stability and causes attitude jitter, resulting in image distortion and geometric accuracy degradation. This paper presents an attitude jitter detection method based on images and dense ground controls, which requires neither high-performance attitude measurement devices nor specific sensor configuration like parallax observation. Attitude variations will result in image space discrepancies at control points, from which the attitude jitter can be retrieved. The method was validated by a case study with ZY-3 satellite, which is the first civilian high-resolution stereo mapping satellite in China. The experimental results show that an almost constant jitter frequency of about 0.65 Hz was detected, which was consistent with the direct attitude observations. The photogrammetric method is theoretically capable of detecting attitude jitter up to half of the image line scanning rate according to Shannon's sampling theorem, which is far beyond the detectable range by direct attitude observations at a frequency usually not higher than 4 Hz. Currently, the attitude jitter of the roll angle and the pitch angle can be effectively detected and accurately estimated for the nadir camera. The pitch angle jitter is also well estimable for the forward and the backward cameras. With approximation, the roll angle jitter for the two off-nadir cameras can also be estimated, though with some deviation caused by the influence of the yaw angle jitter.