三线阵立体测绘相机高精度时间同步设计方法

High precision time synchronization design of three-line array stereometry camera

为保证图像定位精度,三线阵立体测绘相机需要具有高精度的时间同步功能,研究了一种时间同步设计方法。以GPS硬件秒脉冲信号做为时间基准,结合总线广播的整秒时刻信息以及相机内部计时器数据来记录成像时刻。详细描述了时间信息产生链路上各部分的设计,通过这种硬件和软件相结合的办法,解决了时间基准和时间精度的问题,实现了三线阵立体测绘相机与整星的高精度时间同步,为图像后期地面处理提供了有力的保障。经过实验验证,三线阵立体测绘相机的时间同步精度为优于15μs,满足图像测绘精度的要求。

According to the requirement of high precision time synchronization in three-line array stereometry camera,a design method of time synchronization is introduced based on the analysis of working principle of the time system in this paper.The GPS hardware second pulse signal is regarded as time reference,then the second time information corresponding to the second pulse broadcast by bus and internal counter data set in the signal processor of the camera are also used to record the imaging time.Each part on the path of time system is described in detail.With the combination of hardware and software,the difficult problem that ensure time reference and time accuracy is solved.Therefore,high precision time synchronization between three-line array stereometry camera and the satellite is realized.The experiment results show that the time synchronization precision of three-line array stereometry camera system is better than 15μs,which meets the requirement of remote sensing image stereometry precision.