不同控制條件對GPS輔助大比例尺空中三角測量精度之影響

Influence of Control Patterns on the Accuracy of the GPS Supported Aerial Triangulation

王宏仁(Hung-Jen Wang) ； 王蜀嘉(Shue-Chia Wang)

《航測及遙測學刊》 3卷2期 (1998/06) Pp. 1-15

https://doi.org/10.6574/JPRS.1998.3(2).1

摘要

以GPS動態測量，於航空攝影時測定攝影站坐標，供作空中三角測量平差計算時的控制點之用，可以替代傳統在地面上佈設大量控制點之工作，以降低航測空中三角測量的成本。國外有關這方面的研究與測試報告已不少。但在國內因缺少這方面設備，一直無法實際測試。受限於經費，成功大學測量系在自行拼湊低價購置之不同廠牌單元組合後，歷經多次試飛，已完成初步之試驗結果，並對不同的控制條件對精度的影響作出研究。經過在地面上佈設檢核點檢核的結果，證實在適當的控制條件下以及適當的賦予投影中心權，確實可以達到臺灣地區大比例尺（攝影比例尺大至1/5000）的精度需求。由實際實驗中，吾人亦發現一些在高精度之應用時應注意的問題，本文在簡單介紹過GPS輔助空中三角測量的理論及系統組合後，將對影響GPS輔助空中三角測量的一些重要因素加以探討，以供後人參考。

關鍵字

空中三角 ； 經驗精度 ； 衛星定位測量

並列摘要

The principle of GPS surpported aerial triangulation is to use GPS to determine the coordinates of the camera exposure centers and then using them as controls. The amount of ground control points required for the aerotriangulation adjustment can thus be reduced. In the past few years, considerable researches and developments of GPS supported aerial triangulation have taken place in some countries. But in Taiwan, there is still no any practical experience in this field. This paper presents the first test of applying PGS supported aerial triangulation in Taiwan. The main goals of the test are to study the actual available accuracy on check points under different control patterns, and to try to find out a proper operational method in Taiwan. Due to limitations on budget, we could not purchase any existing system from well known companies. Instead, we assembled the whole system from existing photo- navigation equipments with minimum new purchasing of some necessary equipments. Based on ground check points, it is found out, that under proper control and proper weighting of the PGS determined camera projection centers, the GPS supported aerial triangulation can full fill the accuracy requirement of large scale photogrammetry (1/5000). During the experiment, we have also found out some problems which need to be taken care of in high precision applications. These problems will also be analyzed in this paper.