後處裡精密單點定位服務CSRS-PPP與RTX-PP靜態成果比較

A Comparative Study on CSRS-PPPP and RTX-PP in Static Mode

「精密單點定位」是直接對觀測量予以改正，由而計算待定點位坐標的作業方法，是全球導航衛星系統中的「絕對定位」方式，僅需於單站觀測即可進行。由於是「絕對定位」，直接所得點位坐標即以計算時所使用之衛星軌道基準為基準。隨同近年科技之進展，「精密單點定位」技術在實務上已經達到應用的階段，尤其是可以使用「精密星曆」之後處理方式。本文以兩個「精密單點定位」後處理的網際服務為標的，探討在使用相同基準時，相同觀測量計算成果之差異。這兩個網際服務分別為加拿大CSRS-PPP、Trimble RTX-PP，前者為政府所提供之開放服務，後者為商業公司提供之免費服務。本研究所進行之計算，為使用於固定站所蒐集之觀測量，取樣間隔30秒之靜態解，比對之基準為ITRF 2014在數據觀測時刻，亦即2022年9月(2022.7)。

'Precise Point Positioning (PPP)'' is an operation method that directly corrects the observations for deriving the coordinates of the point to be positioned. It is the ''absolute positioning'' method in the Global Navigation Satellite System, and it only needs to be observed at a single station. Because it is ''absolute positioning'', the directly obtained point coordinates are in the same datum of which the satelli te orbi t used. Wi th the development of science and technology in recent years, PPP technology has reached the stage of appl icat ion in pract ice, especial ly post -processing methods wi th ''precise ephemeris''. This paper compares the coordinates obtained from two PPP post-processing Internet services, with the same observation. These two Internet services are Canadian CSRS-PPP and Trimble RTX-PP. The former is an open service provided by the government, and the latter is a free service provided by a commercial company. The calculations performed by this study are static solutions using observations collected at a Continuously Operating Reference Station with a sampling interval of 30 seconds. The datum in which the comparison was made, is the epoch of ITRF 2014 at which the observations were made. That is, September 2022 (2022.7).