Web-Based Online Post-Processing GNSS Service InaCORS BIG for Mapping Control Point Positioning for Channel or Road Design

One of the stages in the topographical mapping work is the measurement of the horizontal control framework, which is currently almost all done using GNSS satellite technology. The online post-processing services provided by the Indonesian Geospatial Information Agency (BIG) are called xpos-InaCORS. Using this service, measurements are possible using only 1 GNSS receiver can be used for measurement and obtained of the mapping control framework. This research was conducted to determine the accuracy of the online post-processing method by xpos-InaCORS BIG when used as a control point for the mapping of the route of the channel or road which tends to be elongated with a 3rd order (SNI 19-6724-2002). The coordinates of the results of the online processing calculation are compared with the results of the static differential method, which is calculated using commercial software (Leica Infinity). The results showed that at this location, observations for 15 minutes on each benchmark were able to produce an accuracy of 1 centimeter, and to comply with the qualifications of order 3rd SNI, observations must be a minimum duration of 75 minutes. The cost of observation on the online post-processing method requires 60% of the static differential. Observation at 75 minutes resulted in an average accuracy of northing (N) = 15mm and easting (E) = 8mm.