GPS接收儀天線多路徑效應之研究

Abstract

本論文旨在研討GPS觀測量多路徑效應及其對定位之影響，擬用GPS訊號與衛星－天線幾何關係為理論基礎，發展GPS接收儀天線多路徑效應偵測演算法，以建立有效的偵測多路徑效應之指標，確切掌握多路徑效應發生之時機與數量。進而將上述之多路徑效應偵測演算法引用於GPS相對定位測量，分析多路徑效應變化對GPS靜態測量之影響。 實驗設計包括兩部分，即長基線及短基線。硬體採用雙頻GPS接收儀及接收天線，軟體採用多路徑偵測程式及基線解算程式。 本論文的目標是評估天線多路徑效應偵測法之有效性及適用性，並確定接收儀天線多路徑效應對GPS定位結果之影響，祈能改善GPS測量外業步驟。

The subject of this research is to study the multipath effect of GPS antenna on positioning. An algorithm based on GPS signal structure of dual-freqency and geometry of satellite-reflector-receiver to detect multipath of GPS antenna is presented. This algorithm is derived to be the index of multipath occurred and to be applied to assist editing cycle slips of carrier phase measurements. The developed algorithm is also adopted to analyze the multipath effect of GPS antenna on GPS static surveying. The designed experiments are consist of two parts: short baselines and long baselines. The hardware used in the project is dual-frequency GPS receivers and antenna. As for the software, the developed multipath detecting program and existing baseline computation programs are adopted. Thus, the main goals of this research are to evaluate the effect and feasibility of the developed algorithm, to study the multipath effect on GPS positioning, and to modify the specification of GPS survey.