Abstract:We first present a mathematical model of medium-long baseline kinematic positioning based on BDS triple frequency observations. Several baselines from CORS in Tianjin, Wuhan and Guangdong are adopted to evaluate and analyze the TTFF and the accuracy of BDS medium-long baseline kinematic positioning. In terms of the present BDS constellation, the TTFF shows strong correlation with the latitude and observation period. The TTFF in the north of China is about 2 h, while it is about 1.5 h to less than 1 h in the middle and south of China. With the right fixed ambiguity, the east and north accuracies of the baseline are 2.5 and 2.1 cm respectively, while the vertical accuracy is 61 cm.