一种基于路径筛选的地形匹配算法

Terrain matching algorithm based on path screening

为了减少传统的匹配算法过大的计算量,提高地形匹配算法的实时性和工程实用性,通过对地形辅助导航系统的总体技术研究,提出了一种基于路径筛选的新型地形匹配算法,利用地形斜率,在飞机飞行过程中不断筛选可能路径,直到找到唯一的正确路径,从而实现精确定位。此算法的优点在于:充分考虑了无线电高度表、大气高度表、数字地图的误差,因此在存在较大误差的工程实际中仍能精确定位;由于在飞行过程中不断排除不可能路径,因此计算量大大减少。通过实验室仿真证明,此算法精确可靠,可以对惯导系统的定位误差做出有效校正。

In order to reduce computation burden and improve real-time and engineering practicability, a new algorithm of terrain matching based on path screening is proposed by means of the study on a terrain aided navigation system. The algorithm uses terrain gradient to screen the likelihood path during the flight of airplane, and then select the right path to realize the precise orientation. The advantage of the algorithm is that the high precision orientation can be realized even when there exists large errors, because the errors of the radio altimeter, barometric altimeter, digital map are totally considered. The amount of computation is reduced due to excluding the impossible path during flying. The simulation results show that the algorithm is accurate and reliable, which can make a valid calibration to the INS error.