Abstract:In order to solve the negative eff ects of GNSS diff erential signal interruption in river survey,the precision and rate of change of GNSS single point positioning are analyzed,the data collected during difference signal interruption is corrected by using the single point positioning post-processing technology,and the error is analyzed statistically. The results show that the error of single-point positioning data is acceptable after correction by postprocessing technology,and the data can meet the quality requirements,thus avoiding unnecessary rework caused by diff erential signal interruption aff ecting result quality. GNSS single point positioning post-processing technology can play a very good complementary role in river survey,which can also serve as a reference in river survey and off shore underwater topographic survey,especially in small scale underwater topographic survey.