Abstract:In order to discuss the impact on the adjustment of gravity network structure, the latest four groups gravity data of the upgraded northern Tianshan gravity network are used to analyze the impact of the long open line in gravity network. The results show that the existence of long open line in the gravity network brings the maximum gravity change is up to 260 μGal. Meanwhile, when the open lines are converted into a closed loop, the maximum is 60 μGal. Therefore, accumulation of error on the open line causes unreliable gravity value on the station at the end of the open line. Consequently, the identification of anomalous gravity change will be seriously affected. In order to improve the reliability of adjustment result effectively, proper data processing method is adopted to convert the open lines into a closed loop, when some long lines exist in gravity network owing to the observation work, helping to identify anomaly information.