When working at high latitudes, the elevation of L-band satellites decreases. Dedicated L-band antennae such as the VERIPOS 90984 and V86 can generally track the L-band satellites down to around 10° Elevation (Approximately 70° latitude depending on exact location). Combined antennas (GNSS+L-band) generally stop tracking L-band satellites at a slightly higher elevation.
For receiving VERIPOS corrections at high latitudes, alternative delivery methods should be considered. Some alternative means of receiving VERIPOS corrections are:
The VERIPOS Verichart software can be used to enter the worksite location and check the elevation(s) to the relevant L-band satellites. This will help identify if there are likely to be issues receiving corrections by means of conventional L-band antennae:
At high latitudes GNSS reception can be affected because there will be fewer satellites directly above the worksite. If using GPS satellites only this could lead to a low satellite count or poor satellite geometry, both of which could potentially lead to a loss of DGNSS position.
To combat these issues, the use of GLONASS satellites in addition to GPS should be considered*. This will significantly increase the number of available satellites at any one time and also improve the geometry.
*The VERIPOS equipment/software must have the correct permissions and access codes before GPS + GLONASS solutions can be used.
GPS Satellite Sky Plot at 70°N
GPS + GLONASS Satellite Sky Plot at 70°N