Clear view of the sky
GPS and GNSS antennas receive low-power signals from satellites. For reliable operation, the antenna should have a wide, unobstructed view of the sky. Roofs, walls, metal structures, and dense construction materials can block or weaken satellite signals.
Window installations
In many installations, an antenna can work near or in a window if the window has a direct view of the sky and the antenna is placed close to the glass. Reliability depends heavily on the surrounding environment.
Dense urban environments
In city centers or areas with tall buildings, satellite visibility can be reduced and signals can reflect off structures. This can lead to weaker reception or intermittent lock even when an antenna appears to be placed correctly.
Underwater operation
GPS and GNSS signals do not propagate through water. If an antenna is submerged (for example on submersible vehicles), satellite reception will be lost until the antenna returns above water with a clear view of the sky.
Checking an installation with intermittent lock
- Record the antenna model, cable type and total length, connectors, surge protection and any amplifiers.
- Confirm a clear sky view and inspect the cable and connectors for damage.
- Compare reception with a short, known-good compatible antenna/cable setup. Improved reception points to the installed signal path for further investigation.
- After correcting the identified issue, observe satellite reception and lock over the period in which dropout previously occurred.
Key takeaways
- Best performance requires a clear sky view.
- Windows can work, but performance varies with surroundings.
- Tall buildings can reduce reliability.
- GPS/GNSS does not function underwater.
Article ID: KB-GPS-003
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