Abstract:Correction models,data preprocessing,and solving approach of GPS precise positioning software LTW_BS are introduced.Two-year-data from Shanghai CORS network and data from Jiangsu CORS network composed of 70 stations are processed.Results show that LTW_BS is reliable and stable.With LTW_BS,millimeter level accuracy for a 100 km regional static network and 2 cm accuracy for a large scale network up to a thousand of kilometer are expected.