多參考站GPS動態定位演算法之研究

Research on GPS Kinematic Positioning with Multiple Reference Stations

朱康文(Kang-Wen Chu) ； 吳究(Joz Wu) ； 謝吉修(Chi-Hsiu Hsieh)

《航測及遙測學刊》 13卷3期 (2008/09) Pp. 183-194

https://doi.org/10.6574/JPRS.2008.13(3).3

摘要

中長距離GPS定位存在與距離相關的各種誤差，如大氣折射，這些誤差使單時刻相位模稜解算成功率降低，進而影響定位精度。使用多參考站可以模式化參考站與使用者間與距離相關的各種誤差，期望可以增加使用者的移動距離或提升定位精度。本研究目的在利用已知坐標，找出參考站間的相對對流層天頂向延遲(Relative Tropospheric Zenith Delay, RTZD)，並提供移動站內插改正數，以得到更精確的定位結果。主要工作分爲三個階段：(1)使用虛擬RTZD 觀測方程式，計算參考站間的RTZD；(2)根據參考站數目，選擇適當的改正面函數；(3)動態定位。本研究方法僅需使用一至三時刻觀測量即可成功獲得定位整數解，可降低周波脫落或資料中斷影響。實驗結果指出，若能正確求得參考站間RTZD，並使用適當的內插模式，則可改善定位精度。

關鍵字

多參考站 ； GPS動態定位 ； 對流層天頂向延遲

並列摘要

The distance-dependent GPS errors, notably atmospheric refraction, reduce the success rate of epoch-by-epoch ambiguity resolution, and limit the GPS positioning accuracy, especially for mediumto long-range baselines. Using multiple reference stations to model (or interpolate) the distance-dependent biases between the reference station and a rover can extend the distance or improve the positioning accuracy. The objective of this research is to find out the relative tropospheric zenith delays (RTZD) between different reference stations by using known coordinates and to provide rovers with interpolated corrections for more precise positioning. The project consists of three major steps: (1) finding out the RTZDs between reference stations, (2) modeling the RTZDs; (3) kinematic positioning. In the first step, a pseudo observation equation of RTZD is added in order to reduce the impact of RTZD on ambiguity resolution. In the second step, different model is used according to the numbers of reference stations. These two steps are the emphases of this investigation. The proposed method needs only one to three epochs to resolve ambiguities, so the effects of cycle slip or data gap are not very serious. A multiple reference stations network located in north Taiwan is used in this research. There are six permanent GPS stations in this network. Test result indicates that if the RTZDs between different reference stations can be resolved successfully, and a proper interpolation model is used, it is possible to improve the positioning accuracy.

並列關鍵字

Multiple reference stations ； GPS kinematic positioning ； Tropospheric zenith delay