Science and Technology on Inertial Laboratory, Key Laboratory of Fundamental Science for National Defense-Novel Inertial Instrument & Navigation System Technology, Beijing 100191, China.
Sensors (Basel). 2012;12(5):6712-26. doi: 10.3390/s120506712. Epub 2012 May 22.
The precision of star point location is significant to identify the star map and to acquire the aircraft attitude for star sensors. Under dynamic conditions, star images are not only corrupted by various noises, but also blurred due to the angular rate of the star sensor. According to different angular rates under dynamic conditions, a novel method is proposed in this article, which includes a denoising method based on adaptive wavelet threshold and a restoration method based on the large angular rate. The adaptive threshold is adopted for denoising the star image when the angular rate is in the dynamic range. Then, the mathematical model of motion blur is deduced so as to restore the blurred star map due to large angular rate. Simulation results validate the effectiveness of the proposed method, which is suitable for blurred star image processing and practical for attitude determination of satellites under dynamic conditions.
星点定位精度对于星图识别和星敏感器获取飞机姿态至关重要。在动态条件下,星像不仅受到各种噪声的干扰,而且由于星敏感器的角速率而变得模糊。根据动态条件下的不同角速率,本文提出了一种新的方法,包括基于自适应小波阈值的去噪方法和基于大角速率的恢复方法。当角速率处于动态范围内时,采用自适应阈值对星像进行去噪。然后,推导出运动模糊的数学模型,以恢复由于大角速率而模糊的星图。仿真结果验证了所提出方法的有效性,该方法适用于模糊星图像处理,并且对于动态条件下卫星的姿态确定具有实际意义。