用GPS监测城市地面沉降的可行性研究

FEASIBILITY STUDY OF URBAN LAND SUBSIDENCE MONITORING BY GPS SURVEYING

研究了用GPS观测取代常规水准测量方法监测城市地面沉降变化的可行性。在宁波市进行了两期GPS测量和水准测量 ,观测中并采取一定的措施以获得高精度的高程分量。顾及到对流层延迟的影响 ,采用Saas tamoinen模型改正对流层延迟的干分量部分 ,用分段线性方法来估计对流层的湿分量变化。用Bernese软件对数据进行处理 ,获得了毫米级的高程精度。实际算例证明 ,用GPS测量代替水准测量来监测城市地面沉降变化是可行的。

In order to study the feasibility of monitoring the change of urban land subsidence by GPS surveying instead of leveling, two periods of GPS observation and leveling were completed respectively in Ningbo city. Some technical measures were taken during GPS observation in order to ensure to obtain the high precise height component. Considering the affect of tropospheric delay,the Saastamoinen model was adopted in the data processing of the dry component of the tropospheric delay. The wet component change of the tropospheric delay was estimated by use of the piece wise linear method. When Bernese software was used to process the data, the mm level accuracy of height measuring was achieved. It is verified by the practical example in this paper that monitoring the change of urban land subsidence by GPS surveying instead of leveling is feasible. It will help to advance the efficiency of subsidence monitoring.