Global Positioning System (GPS) has become widely known among the general public through its application in car navigation systems.
It has been used in the surveying industries even before it became a widespread application in car navigation systems.
What is GPS Surveying?
Locations (latitude, longitude, and altitude) are computed using radio waves transmitted from satellites. Through GPS, it is possible to determine locations to a high degree of accuracy. Today, this technology is widely used in basic and public surveying in Japan, with the objective of maintaining and managing the national territory.
- Precision geodetic network high-altitude area control point surveying
- Geoid surveying
- Control point surveying operations accompanying national land surveys
- Revision of control point in areas with inconsistent results
Precision geodetic network high-altitude area control point surveying
Precision geodetic network high-altitude area control point surveying is a basic control point survey aimed at detecting crustal movements, and surveying is carried out by the Geospatial Information Authority of Japan. Using electronic control points as the known points, all points are surveyed using GPS surveillance for more than six hours, using more than four units of GPS surveying equipment. The degree of precision required is obtained by seeking the relative location of the control points three-dimensionally at a precision of 0.1 ppm (1 mm for 10 km).
We have succeeded in enhancing work efficiency and reducing costs through network-based RTK-GPS surveying (VRS format).
- Third/Forth grade control point surveying
- Establishment of a central pile and a land width pile in road surveying
- Operations to establish road control points
- GCP acquisition operations
Network-Based RTK-GPS Surveying (VRS Format)
VRS format is a format that seeks position coordinates using mobile phones, and is not as simple as a portable GPS.
Through mobile phones, the approximate location information is transmitted from mobile stations to location information service providers (distributor businesses). Distributor businesses create hypothetical control points at approximate locations based on the observed quantity of electronic control points around the mobile stations. They then compute the corrected information and phase data for these points, and send them back to the mobile stations. Thus, RTK-GPS surveying is carried out based on the corrected information and phase data that is sent back, and position coordinates are sought through this complicated process.
Network-based RTK-GPS (VRS format) can obtain position coordinates of the location observed with a high degree of accuracy known as errors of centimeters. However, for areas that are not reachable by mobile phone signals and radio waves, and in areas where GPS observation cannot be carried out under sky visibility conditions, the technology is used jointly with "TS radio waves measurement."