论文部分内容阅读
用激光进行深空探测科学数据回传,上行信标光衰减严重,不能提供足够高的跟踪速率,因此常采用自然天体图像作为信标。对该信标的捕获和跟踪是深空光通信链路成功建立和保持的关键。在航天器上存储一幅目标天体图像做参考,利用该图像和探测图像的相关性对该信标进行捕获,理论分析和仿真结果都表明,可以精确地确定光通信天线的初始对准方向,使跟瞄系统进入跟踪模式。基于离散傅里叶变换和极大似然方法对信标的平移进行计算,需要解一个非线性方程组,线性近似计算结果表明平移量总误差在0.5个像素以内,X方向的平移误差为3.3%,Y方向的平移误差为2.7%,可以满足深空通信的要求,因而是一种可行的方案。
Using laser to return the scientific data of deep space exploration, the uplink beacon light attenuates severely and can not provide a sufficiently high tracking rate, so the natural celestial body image is often used as a beacon. The capture and tracking of the beacon is the key to the successful establishment and maintenance of a deep space optical communication link. A target celestial body image is stored on the spacecraft for reference. The correlation between the image and the sounding image is used to capture the beacon. The theoretical analysis and simulation results show that the initial alignment direction of the optical communication antenna can be precisely determined, Make follow-up system into tracking mode. To calculate the translation of the beacon based on the discrete Fourier transform and the maximum likelihood method, a nonlinear system of equations needs to be solved. The linear approximation results show that the total translation error is within 0.5 pixel and the translation error in the X direction is 3.3% , And the translational error in the Y direction is 2.7%, which can meet the requirements of deep space communications. Therefore, it is a feasible solution.