The robot must be erected for operation on a stable pillar or tripod and it must be levelled and orientated. A special mounting device is used to set-up the robot on a 5/8″ adaption and to level it. The north orientation is corrected within the software. A DIN-socket is attached to the top of the robot to mount GNSS antennas.
Currently, the power supply of the robot manufacturer can only be operated indoors. Therefore a cable length of 15m is used. Referring to the robot manufacturer, the power supply must give 24 V/40 A as well as 48 V/20 A to provide proper operation.
There are a variety of adequate sites to operate the robot. Different aspects should be considered for the selection:
- set-up height (enable easy handling, mounting of antenna)
- visibility between operator and robot (certain procedures and movements require operator interaction; video control)
- weight and stress through robot and antenna
- satellite visibility/satellite obstruction (performance, reducing diffraction)
- power supply and data communication (robot, but also GNSS data of antenna and second PDGPS station)
- lightning protection
The calibration procedure assumes same satellite visibility on the robot and the second PDGPS station. The visibility on the robot is checked, however, visibility should be ensured on both sites. Partial obstruction or restrictions on a clear horizon are then not relevant for the calibration. The satellite visibility can affect the duration of a calibration.
The antenna calibration generally uses an elevation mask of 18 deg for observations to avoid multipath signals from low elevations. Obstructions due to buildings and others should be significantly below the elevation mask to reduce any effects coming from diffraction. Diffraction cannot be accounted for the adjustment model, because it may contain discontinuities. Due to the tilting capabilities of the robot, the complete antenna hemisphere is calibrated up to the horizon. To constrain the PCV determination at the horizon even observations up to -5 deg elevation rsp. 5 deg below the antenna horizon are used.
Experiences with Robot Setups
The robot has been operated on different sites. The following pictures show some robot setups
- pillar at Geo++ (0.30m x 0.30m x 0.80m)
- setup on round pillar (ife, University of Hannover)
- portable mount at an exhibition (ife, University of Hannover)
- fix tripod mount (Senate Office of Urban Development Berlin)