Abstract: Based on the GNSS continuous observation data of CMONOC in 2011 and 2012, troposphere delay error and initial coordinate error in the GPS high precision processing are analyzed. Campaign observations with different time intervals were simulated by resampling to test the precision. The results indicate thatin order to get high precision time series ,troposphere delay must be calculated. The precisions of results with different troposphere parameters are equal,such as 2,7,13,the right number should be picked according to the calculation needs. Time series with high precision could be obtained when the initial coordinate error is within 10m, however,when the initial coordinate error is 30 m or 50 m,we can not obtain the available time series. When the time interval of campaign observation is larger than 1 year,velocity field with reliable precision can be obtained,while the time interval shorter than 1 year, the precision of the result is lower.

Key words: GPS data processing, Horizontal velocity field, Troposphere error