Precision Processing and Accuracy Evaluation of BeiDou-3 System Data in Beijing

In response to the current situation where Beijing's benchmark maintenance relies solely on GPS data, we conduct in-depth research on the positioning accuracy of different dual frequency and orbit combinations of the BeiDou system.Gamit software is used to calculate the benchmark station data for seven consecutive days, and we compared the positioning performance characteristics of the BeiDou and GPS systems with different frequency and orbit combinations.The positioning accuracy of the BeiDou system is evaluated from three aspects: standardized root mean square error, baseline repetition rate, and coordinate difference.The results show that in the Beijing area, the positioning accuracy of different frequency combinations of the BeiDou-3 satellite system is higher than that of the BeiDou-2 system.The B1C/B2a frequency positioning accuracy of BeiDou-3 is higher than that of B1I/B3I frequency points, and the orbit combination of MEO+IGSO has the highest positioning accuracy among all combinations.This discovery not only provides new technological options for our city's benchmark maintenance work, but also provides more scientific and accurate surveying and mapping benchmark support for geographic spatial analysis and natural resource management.