Why keep a geofence register?
Geofences pile up. A depot here, a customer site there, a speed zone someone drew years ago. Nobody remembers who gets the alert, whether it was ever tested, or why the camp gate never triggers. One register with the shape, the rules and the test result of every zone fixes that.
Is the zone big enough for your tracker?
A tracker reports a position every few seconds while it moves. At 60 km/h and one position every 30 seconds, two positions are 500 m apart. A circle of 150 m radius can sit between them, and the vehicle crosses it without one position inside. No entry, no exit, no alert.
Typical value: 10 m of position error in open sky. Replace it with what you measure from your own device on site.
| Setting | Value |
|---|---|
| Position error allowance | 10 mtypical |
| Review every | 180 daysexample |
| Earth radius for distances | 6,371,008.8 m |
Rules, recipients and where they run
A zone without a rule is only a drawing. Each rule row says which event matters, when, for which vehicles, who gets the alert and how. Record also where the rule runs. Some devices can check a zone on board and act with no network, others leave it to the platform. That changes how fast the alert arrives and what happens in a dead zone.
Drive a vehicle through the zone at a normal speed and record whether the alert arrived, arrived late or did not arrive. A late alert usually points to the reporting interval or the network delay.
Limits
The size check is a quick test. For a polygon it uses half the narrowest width as the radius, not a full polygon calculation. The register does not draw zones and does not send anything to a device or a platform. The coordinates in the example rows are made up.