Abstract
This study aims to convert crustal motion velocity and its uncertainties from the topocentric coordinate system to the geocentric coordinate system. The formula for conversion of motion velocity is based on the formula for conversion coordinate. The formula for estimating the uncertainties of motion velocity is built based on the law of error propagation. The test is performed by comparing the combined velocity and the corresponding uncertainties before and after conversion. In the experiment, the motion velocity and corresponding uncertainty of 29 monitoring points were converted from the topocentric coordinate system to the geocentric coordinate system. The test results show that the formula and conversion results are completely accurate. This conversion crustal motion velocity method will facilitate the study of the effect of the crustal motion on the coordinate transformation parameters without having to reprocess the monitoring network.