短距双站在远距基准点上观测目标的定位精度

Observation Target Positioning Accuracy on Distance Base Point Using Short-Range Two Stations

在基于时差-方位测量的短距双基站的数百公里之外,选定一个地图基准位置,并以此地图基准位置作为计算分析远距目标位置的几何坐标起始点。先由双站间的时差方程和几何关系解得目标相对于双站的测距式,然后,利用双站测距式以及双站与远距地图基准点之间的几何关系解得目标相对于地图基准点的径向距离和方位。虽然测向误差很大,但误差分析表明只要双站与地图基准点之间的距离足够远,就能在双站距离小于10km的情况下,使目标与地图基准点之间的测距误差满足小于5%R的精度要求。

Over hundreds kilometers deviated from the short-range two stations which are based on time difference and azimuth measuring, taking a map reference as start point of coordinate setting to analyze the position of distance target. Firstly the ranging formula from two stations to target is solved by the time difference equation and geometric relationship of two stations. Then, the radial distance and target position relative to the map reference can be determined by using the geometric relationship between two stations and map reference point. Although the measurement error is big, error analysis shows that the ranging error between target and map reference can satisfy accuracy requirement less than 5%R while the baseline length between two stations is less than ten kilometers, as long as the distance between two stations and map reference are adequate famess.