台灣地區GPS衛星追蹤站之天線相位中心與天線罩改正之研究

The Study of GPS Antenna Phase Center and Radome Effect for Tracking Station in Taiwan

本文分別利用相對及絕對相位中心改正模式求解台灣追蹤站點位坐標，並藉由約制國際追蹤站進行強制附合平差計算，來分析不同天線相位中心改正對定位精度的影響；另外，在誤植天線罩之情形下，對於GPS資料解算時所造成的影響。研究成果顯示在igs08與igs01兩種相位中心改正模式所計算的坐標成果中，在X分量其差值最大可達3.1 mm，在Y分量其差值最大可達4.0 mm，在Z分量中其差值最大可達7.5 mm；在橢球高差中，其差值最大可達3.3 mm；天線罩誤用計有鳳林、墾丁及陽明山等3個點位，解算成果顯示在X分量上，其影響量介於4.7-4.9 mm，在Y分量上，其影響量介於7.7-7.9 mm，在Z分量上，其影響量介於4.7-5.1 mm，在橢球高差中，其影響量介於10.3-10.4 mm之間，以上結果顯示，天線相位中心改正模式之不同，以及相同天線盤搭配不同天線罩，對於定位結果影響顯著。 This study computed the Taiwan tracking station coordinate from the relative and absolute antenna phase center calibration models by using IGS stations fixed constrained adjustment. The impact of using different antenna phase centers and the wrong radome types on the precision is analyzed. The result of this study shows igs08 model and igs01 model of antenna phase center affects the coordinates in X direction reaches 3.1 mm, in Y direction is 4.0 mm and in Z direction is 7. 5 mm. The ellipsoid height difference is 3.3 mm. There are three tracking stations used the wrong radome which are FLMN, YMSN and KDNM. The results of these three stations show the coordinates in X direction from 4.7 mm to 4.9 mm, in Y direction from 7.7 mm to 7.9 mm, in Z direction from 4.7 mm to 5.1 mm and ellipsoidal height from 10.3 mm to 10.4 mm. From this study, we can get the different antenna phase center model and different radome are important factors in high accuracy GPS survey.