Combination of free network adjustment with Stransformation and Kalman filter with original data information adjustment for displacement analysis

Abstract

To evaluate the displacement of the coordinates of the GNSS network
points according to the measured data of the periods, the theory of free
network adjustment has been widely applied. However, changing the
stable points in the cycles if only considering the coordinate difference
after the adjustment in the normal way will not be accurate because the
result of the free network adjustment of the coordinates is determined
with different origin points. Therefore, it is necessary to convert the
coordinate system of the previous period to the coordinate system of the
following period, applying S -transformation to analyze the deformation.
In addition to the displacement of the points, it is necessary to define the
velocity and acceleration parameters of the displacement. In this paper, a
method of displacement analysis has been studied based on using GNSS
network measurement data in measurement cycles and applying the
theory of free network adjustment and S transformation, Kalman filtering
technique and rationalizing the geodetic network adjustment theory with
the error information of the original data to analyze and predict the
displacement on the experimental area of the Saigon River area. The
analysis concludes the shift based on the student distribution (t -
distribution). In the study, static and dynamic models were considered
and gave consistent calculation results. The theory has been proven to
develop the Kalman filter technique for deformation analysis and
prediction problems by applying GNSS technology. This result allows to
expand the scope of application of GNSS technology for monitoring and
analysis of landslides, subsidence and displacement of the Earth's crust on
a local scale as well as a territorial extent in Vietnam, and can e data from
GNSS CORS observation stations