Research and realization of high-precision GPS datum, considering plate movement, stability and system errors

It is essential to set a rational datum for the GPS adjustment of national or city-level subsidence monitoring. Based on the characteristics of the datum of urban GPS land subsidence network, and the shortage of traditional datum for the urban GPS land subsidence monitoring, this paper puts forward an enhanced quasi-stable datum model by considering the plate movement, stability of the base benchmarks and some other systematic effects. Owing to the consideration of the height effects from stability of base benchmarks and the plate movement and the unified GPS baseline frame and the quasi-stable datum for each epoch monitoring, this model can give reasonable deformation results by correcting the errors from instability of base benchmarks and inconsistent baseline frames of different monitoring epochs. Lastly six Xian GPS land subsidence monitoring datasets are tested and the rationality and feasibility of newly deduced model are verified.