三线阵立体测绘相机时间系统优化与实时检测

为了提高三线阵立体测绘相机的时间同步精度,对相机时间系统工作原理进行了分析,建立了三线阵立体测绘相机的相机时间同步误差模型,并根据该模型采取缩短行同步计数器查询周期等多项措施对相机时间系统进行优化.针对相机时间同步误差在摄影过程中会随相机控制器工作时序变化这一现象,提出了一种实时检测相机时间同步精度的方法,用于实时检测并全程记录摄影过程中相机时间同步误差的动态变化,解决了常规仪器由于存储深度不足而无法长期检测这一难题.利用该方法检测了优化后的三线阵立体测绘相机时间系统的时间同步精度,结果表明,摄影过程中三线阵立体测绘相机的时间同步误差≤74.8μs,相机时间同步误差绝对值≤11.2 μs的概率不低于0.95,满足技术指标要求.

Optimization and real-time measurement of time system in three-line stereo mapping camera

To improve the time synchronization precision of a three-line stereo mapping camera,a time synchronization error model for the three-line stereo mapping camera was set up based on the analysis of working principle of the time system in the camera.Then,several methods such as reduction of row synchronization counter polling period were adopted to optimize the time system.As the time synchronization errors may change with the working time sequence of the camera controller,a real-time time synchronization precision measuring method for the three-line stereo mapping camera was put forward to measure and record the dynamic changes of time synchronization errors in real-time during photographing process globally.With the method,the difficult problem that custom instruments could not be used for long time measurement of time synchronization errors because of their finite memory depths was solved.This method was used to measure time synchronization precision of the time system for the optimized three-line stereo mapping camera.Experimental results indicate that time synchronization errors of the camera are no more than 74.8 μs during photographing process and the probability of absolute value of time synchronization errors no more than 11.2 μs is more than 0.95,which meets the demand of qualification.