Precise single epoch GPS positioning for deformation monitoring

Real-time kinematic GPS systems (RTK-GPS) are used nowadays for many different applications. In the case of deformation monitoring the position determination has to be performed separately for each epoch and the capability of these systems is currently being analysed in many research projects. On the other hand, a single epoch GPS processing algorithm combining the ambiguity function method (AFM) with robust least squares estimation has been introduced recently and can be applied for position determination in deformation monitoring. In this paper the two approaches are compared and results of field tests on large construction sites in Hong Kong are presented. Finally improvements of both methods leading to a combination of the two algorithms are discussed.