Description:
The minimum number of satellites for a reliable position is 5 and HDOP (deviation) should be 1.5 or lower.
To improve your GNSS acquisition, retention and accuracy, please try the following.
Steps:
On the physical tracker:
- Make sure the antenna (label side of the tracker in case of an internal antenna) is:
Facing up perpendicular to the sky.
It is not tilted more than 45 degrees in any axis, with the top surface perpendicular to the sky.
Installed as close to the windshield as possible.
Without any metallic objects or wiring in between.
- You could acquire an external GNSS antenna to improve GNSS fix acquisition. Check compatibility here:
- If problems persist, try doing a deep reset:
disconnect from power supply
disconnect from internal battery (you can do this physically or via Advanced Configurator "Battery off" button).
reconnect internal battery
reconnect power supply
On the configuration:
- Make sure all three GNSS systems are enabled: GPS, GLONASS and GALILEO. This will increase satellite availability and thus fix and accuracy.
Filtering unreliable coordinates:
Without GPS fix:
If record header looks like the one below (all GNSS derived values are maxed out / error), it means the record was generated and sent without first acquiring a GNSS fix.
Coordinates will be:
214.7483648 | 214.7483648 |
While this does not usually happen, because the device will not send a record unless a valid GNSS fix has been previously acquired after first power on / reset, if Send data without GPS fix is checked, the device will nonetheless send the record with the faulty header.
To avoid receiving such records, simply uncheck the box:
With gps fix:
- Enable Navigation filtering
Stationary (discards coordinates that do not meet accuracy criteria when vehicle is not moving).
Active (discards coordinates that do not meet accuracy criteria when vehicle is moving).
(example below is the default, more information HERE)
