GNSS Processing Data Result with Sequential Adjustment Method to Estimate the Monitoring Control Point Coordinate at Sermo Dam

Monitoring a structure building like a dam needs to detect any movement. The movement can be measured by adding control point to measure it. Geodynamic movement, expansion of area monitoring, and detection of ground cracks require by adding the new of control points. The addition of control points in a measurement requires specific data processing strategy. Therefore, it used the sequential adjustment method. This research aims to identify 3D coordinate values and the difference precision of the control points from the sequential adjustment method. The first step of sequential adjustment used five control points with one point considered fixed. The second step was added with five control points. The difference of coordinate precision analysis using sequential adjustment method indicates that there are increased precision in five control points which are processed in the first step. The addition of the coordinate precision ranges from 0,193 to 5,450 cm. Based on the comparative of two variants sample test shows that the precision of coordinates resulted for the first step is significant different from the second step. The results of the comparison between two variants test indicate that the precision of the result in first step does significantly different to the second step.