Abstract：Using continuous GNSS data from the crustal movement observation network of China, we analyze the accuracy and reliability of campaign GNSS stations, and the impact of time span, observation period and observation days for the site velocity. Our results show that: time span has significant impact on the velocity precision of campaign sites. When the time span is about 16 years and the observation period is 2 years for one campaign, the standard deviation of the differences between the campaign and continuous sites is about 0.1 mm/a for the horizontal component, and 0.3 mm/a for the vertical component. Further, the impact of observation days on the differences is less than 0.15 mm/a for the horizontal component and 0.45 mm/a for the vertical component. Besides, with the given time span and observation days, shortening the observation period could improve the accuracy of the campaign GNSS sites.
