一、概况为了提高水平形变测量的精度,在川西地区先后对西昌中网和乾宁小网进行了边角同测试验。由于小网无复测资料,本文重点对西昌中网边角同测资料进行处理和分析。西昌三角网主要是一个以芦山为中心的多边形,全网共7个三角点,组成12条测距边。三角点中有5点为利用原测绘局1958年和1967年选埋的西昌二等三角网点,两点为我队1971年新选埋。边长中最长边达20.1千米,最短边为7.7千米,平均为14.6千米。在1975年和 First, the general situation In order to improve the accuracy of horizontal deformation measurement, in the western region of Xichang has a network and dry Ning small net with the same test with the corner. Due to the small network no retest data, this paper focuses on Xichang network edge with the same measurement data processing and analysis. Xichang Triangle is mainly a Lushan-centered polygons, the whole network a total of seven triangles, composed of 12 ranging edge. There are 5 points in the triangle for using the Xichang second-degree triangular points selected by the former Surveying and Mapping Bureau in 1958 and 1967, and two points were newly elected by our team in 1971. The longest side of the edge of 20.1 km, the shortest edge of 7.7 km, an average of 14.6 km. In 1975 and