Griffin Air - Ground Mode explained
Understand and Set Up Ground Mode Parameters
Written by Daan de Waard
Updated at November 2nd, 2026
Table of Contents
What is Ground Mode?
Ground Mode is Griffin Air's normal operating state when the device determines that it is not in flight. While in Ground Mode, the device operates normally and can collect GPS positions, upload data over the cellular network, and perform other configured tracking functions. When the device determines that it may be in flight, it exits Ground Mode and stops cellular communication and normal positional logging. This allows the Griffin Air to automatically change its behaviour during a flight without requiring the user to enable or disable a flight mode manually.
How does the device exit Ground Mode?
The Griffin Air uses its accelerometer and barometer to detect conditions that may indicate a flight. When the configured sensor conditions are triggered, the device attempts a GPS fix to check its speed. If GPS cannot obtain a reliable fix, or the speed is at or above the configured threshold of 100 km/h (default; configurable), the device can exit Ground Mode. If GPS confirms a speed below this threshold, a temporary GPS override can suppress the flight condition.
How does the device re-enter Ground Mode?
Once the device has exited Ground Mode, it continues monitoring movement and checking GPS speed at scheduled intervals. When movement stops, the device can return to Ground Mode after approximately 30–60 minutes, depending on the timing of its Ground Service checks and any remaining active conditions.
During this period, a valid GPS fix below 100 km/h can activate a five-minute GPS override, temporarily allowing communication without fully restoring Ground Mode. This means that receiving data from the device does not necessarily indicate that it has re-entered Ground Mode.
What happens when the device is out of Ground Mode?
Exiting Ground Mode does not mean that the Griffin Air becomes completely inactive.
The primary purpose is to prevent normal tracking and cellular communication while the device is considered to be in flight. Certain passive or sensor-based functions can continue operating. GPS reception and BLE scanning are passive activities because the device is receiving signals rather than transmitting them.
Sensor data is only timestamped and logged when the appropriate parameters have been configured, such as 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.
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.
