Configuring Ground Mode
Understand and Set Up Ground Mode Parameters
Written by Daan de Waard
Updated at May 19th, 2026
Table of Contents
Ground Mode
The Griffin Air features ‘Ground Mode’, which is an advanced detection mechanism for determining whether a device is in a flight or not. This can be useful for determining when the device should go into a dormant mode so that it doesn't waste power or transgress air safety rules by attempting communication during flight.
‘Ground Mode’ is equivalent to 'normal' operation. That is, operation of the device when it is on the ground and not in flight. Therefore, by default, the device is said to be in ‘Ground Mode'.
When the device is detected to be in flight, it is said to have EXITED ‘Ground Mode’. In this state, cellular uploads and GPS positional logging are suspended until the device determines that it is no longer in flight.
However, the device is not completely inactive while out of Ground Mode. It may still perform certain passive or sensor-based actions, depending on configuration. For example, the device may attempt GPS fixes to determine its speed. These GPS fixes are used to help determine whether the device should re-enter Ground Mode early as a fallback mechanism. They are not used for positional logging while the device is in flight.
The device may also perform BLE scans while out of Ground Mode, if parameterised to do so. GPS reception and BLE scanning are passive actions, as the device is only listening and is not transmitting.
Wi-Fi scanning is not currently performed while the device is out of Ground Mode. This is a current firmware/design limitation rather than a certification limitation. A future firmware release may allow Wi-Fi scanning while the device is in flight.
Sensor data is only timestamped and logged if the user has specifically parameterised the device to do so, such as by using the relevant analogue or digital inputs.
| Jostle based trip detection | |
| GPS Movement | Yes, if configured |
Distinction between Ground Mode and Flight Mode
Although the feature is called ‘Ground Mode', this is simply to distinguish its behaviour from the existing ‘Flight Mode’ feature on Digital Matter devices, which is much less complicated as it is either geofence-triggered or enabled via an async message. ‘Ground Mode' and ‘Flight Mode’ are independent features, but they both achieve the same goal: suppression of cellular communication when the device is deemed to be in-flight.
Configuration
The triggers for exiting Ground Mode are based on feedback from the accelerometer and the barometer. Therefore, the device uses a combination of jostle and ambient air pressure monitoring to evaluate them.
The accelerometer trigger makes use of the built-in jostle detection mechanism to determine whether the physical movement of the device is sufficient enough to deem the device to be in transit. The wakeup thresholds for this have been optimally defined and cannot be modified by the user.
The barometer trigger makes use of two mechanisms in combination: an absolute low threshold and a relative negative delta threshold. If the pressure decreases by a certain amount within a given time, or the pressure goes below a certain value, the condition for exiting Ground Mode will be true. These values have been optimally set and cannot be modified by the user.
Once one, or both, of these triggers becomes active, the device will first attempt a GPS fix to determine its speed. If the speed is below the default configured threshold of 100km/h, the device will not exit Ground Mode. If the device is unable to attain a GPS fix or the speed is above this threshold, it will exit Ground Mode.
The GPS fix is used as a temporary suppressor, whereby the device will not exit Ground Mode if it is able to get a fix and determines that the speed is below the configured threshold (meaning that the device is actually not in-flight).
If a device has exited Ground Mode (e.g. it is flying), it will attempt GPS fixes every 30 minutes to determine whether this speed condition is still valid. These GPS fixes are used for Ground Mode state evaluation only and do not result in positional logging while the device is in flight.
Note
Ground Mode detection is enabled by default and cannot be disabled unless explicitly unlocked by a Digital Matter employee.
Certain data relating to Ground Mode can be logged using the System Parameters. This includes:
- The state of Ground Mode as a Digital Input.
- The state of the Accelerometer trigger as a Digital Input.
- Whether the Barometer trigger has been activated and which actions to perform based on the activation and deactivation of this trigger.
- Optional periodic sampling of the ambient air pressure and logging it to an Analogue Input.
Note
While the Griffin Air has no configurational restrictions on the type of trip tracking mode that can be configured (Periodic, GPS Movement or Jostle), it is important to note that the device has been designed for use in Periodic Tracking mode. For other tracking modes, if a device is in a trip and it exits Ground Mode at any time, the current trip will be ended, and the device will sleep for at least 15 minutes or until both of the activation triggers are no longer active. This will be the case if the speed of the device is over the default GPS threshold or the device is unable to attain a GPS fix at any time during a trip. In these cases, trips might appear fragmented.
