Using Xopoz in Airplane Mode

Can I still use GPS tracking when airplane mode is enabled?

Short Answer

Yes. Xopoz continues to acquire and record your GPS position in airplane mode. GPS works because your device's GPS receiver is a passive radio that listens to satellites — it does not transmit anything. Airplane mode only disables the transmitters (cellular, Wi-Fi, Bluetooth), so the GPS fix itself is unaffected.

What you lose in airplane mode is networking: new map tiles cannot be downloaded, and your position will not be synchronised with your team until connectivity is restored.

How GPS Works While Airborne or Offline

A common misconception is that GPS requires an internet connection. It does not. The Global Positioning System is a one-way broadcast: 24+ satellites in medium Earth orbit continuously transmit precisely-timed radio signals on the L1 frequency (1575.42 MHz). Your phone's GPS chip listens to these signals and calculates its position locally by triangulating the time-of-flight from at least four satellites. No data ever leaves the device for the position fix itself.

Because the GPS receiver is receive-only, it has no transmitter to disable. Airplane mode targets transmitters to comply with aviation regulations — cellular radio, Wi-Fi, and Bluetooth — but leaves the passive GPS receiver fully functional. On most modern Android devices (Android 7.0+), GPS remains active even when airplane mode is enabled, and on devices where it is disabled by default, you can re-enable GPS manually while keeping airplane mode on.

Why Xopoz is Well-Suited for Airplane Mode

Xopoz was designed from day one to work without Google services. Most location apps depend on Google Play Services (the FusedLocationProviderClient), which requires network calls to Google servers and may fail entirely when offline. Xopoz instead uses the native Android LocationManager API, talking directly to the GPS hardware. This means:

No Google dependency: GPS fixes work on de-Googled phones, custom ROMs, and on any device in airplane mode
No network prerequisite: Position acquisition happens entirely on-device
No cloud round-trip: Your coordinates are never sent to a third party to be "resolved"

What Works in Airplane Mode

Fully Functional

GPS position acquisition from satellites (direct Android LocationManager API)
Local position history recording — all positions are encrypted on-device and written to local storage regardless of network state
Track recording — GPX tracks continue to accumulate points in the local database
Movement detection — the hardware Significant Motion sensor and the 50 m distance / 1.9 km/h speed thresholds all operate on-device
Map display of cached tiles — any tile previously downloaded by osmdroid remains available from the local tile cache
Navigation to stored POIs — Points of Interest are stored in a local Room database and can be targeted, displayed, and edited without any connectivity
Compass and bearing — the device magnetometer and gyroscope do not need a network
Last-known team member positions — the most recently-synchronised positions remain visible on the map from local cache
Battery-optimised tracking modes — MODE_ACTIVE and MODE_POWER_SAVE transitions continue to work (power save falls back to network-only, which is unavailable in airplane mode, so GPS stays the primary source)

What Stops Working

Requires Network Connectivity

Downloading new map tiles — tiles outside the cached area will appear as empty grey squares until you return to an area of pre-cached coverage
Team position synchronisation — your encrypted GPS positions will not reach the server, and you will not receive fresh positions from other team members
Messaging — outgoing and incoming encrypted messages (SOS alerts, geofence notifications, team chat) are paused
Team list refresh — new members joining the team won't appear until reconnection
Geofence alerts from other members — your own geofence crossings are still detected locally, but delivery of notifications is deferred

Technical Note: Assisted GPS (A-GPS)

When your device has recently had a data connection, it downloads A-GPS almanac data — a prediction of satellite positions — which allows the GPS chip to get a "warm fix" within seconds. In prolonged airplane mode this data expires (typically after 1–4 hours), so the very first fix after a long offline period may take 30–60 seconds as the GPS chip performs a "cold start" and downloads the almanac directly from the satellites. This is a GPS-hardware behaviour common to all navigation apps, not a Xopoz limitation.

Preparing Xopoz for an Offline Trip

Because Xopoz keeps working in airplane mode, you can plan ahead to maximise its usefulness during a flight, a hike in the wilderness, or any situation where connectivity is intermittent or forbidden.

1. Pre-cache the map area

Before going offline, open Xopoz with an active connection and pan across the region you'll visit at every zoom level you might need. The osmdroid rendering engine stores each downloaded raster tile in a local SQLite cache, keyed by zoom level, X, and Y coordinate. Once a tile is in the cache, it can be displayed indefinitely without a network call.

Tip: Zoom out fully and pan across the wide area first, then zoom in on critical spots (start, destination, waypoints) to capture detail-level tiles. Raster tiles only — Xopoz does not use vector tiles.

2. Configure a custom or local tile server (advanced)

For extended offline deployments (expeditions, air-gapped environments, military use) Xopoz supports user-defined raster tile servers. You can point Xopoz at a local tile server running on your laptop, a field-deployed Raspberry Pi, or a private enterprise server. The Settings Module lets you define the base URL, zoom range, tile format and live-test the server connection.

3. Enable local position storage

Make sure Local Save Permission is enabled in the Privacy settings. Xopoz uses a dual-permission model: positions can be saved locally, pushed to the team, or both. With local save enabled, every GPS fix is encrypted with your device key and written to the position history file, regardless of network state.

4. Save your POIs before departure

POIs (Points of Interest) live in a local Room database. Any POI you create or receive from your team before going offline will remain available for navigation. The map cross-hair can target these POIs, and Xopoz will compute distance and bearing to them using only the on-device GPS fix — no routing server needed.

What Happens When Connectivity Returns

Xopoz is designed around a queue-and-flush model: anything that couldn't be sent while offline is retained locally and transmitted automatically when the network comes back.

Position sync: Positions recorded offline are batched and pushed to the server on the next successful API call. The server receives only the encrypted ciphertext — coordinates are never exposed.
Geofence events: Boundary-crossing events that occurred offline are stored in a persistent queue with no time limit, and delivered to the intended recipients once the network returns.
Team roster: If the team list refresh failed during the outage, the previously-cached roster is preserved. Xopoz never wipes local team data on a failed API call.
Messaging queue: Outbound encrypted messages (including SOS alerts composed offline) wait in the local Tp queue and are dispatched by the FlushWorker on reconnection.

⚠ Important Limitations to Keep in Mind

Emergency SOS alerts cannot leave the device while in airplane mode. The SOS message is composed, encrypted, and queued locally, but delivery depends on a working network transport. In a genuine emergency, you must re-enable cellular or Wi-Fi for the alert to reach your team. Plan accordingly for trips into remote areas — a satellite messenger (Garmin inReach, SPOT, etc.) is the appropriate tool when cellular coverage is uncertain and lives are at stake.

Similarly, your team will see your last-known position (the one from just before you switched to airplane mode) and will not be aware that you are continuing to move until you reconnect.

Summary

Capability	Airplane Mode	Notes
GPS fix acquisition	Works	Direct LocationManager, no network required
Position history recording	Works	Encrypted and written to local storage
Track recording (GPX)	Works	Points accumulate in local Room database
Cached map tiles	Works	osmdroid raster cache serves previously-downloaded tiles
New map tiles	Blocked	Requires HTTP to tile server — pre-cache before going offline
POI navigation	Works	POIs stored in local Room database
Compass & bearing	Works	Hardware magnetometer and gyroscope
Team position sync	Blocked	Positions queue locally and flush on reconnection
Team member positions	Cached only	Last-known positions shown; no fresh updates until reconnection
Emergency SOS delivery	Blocked	Composed and queued locally, sent on reconnection
Geofence detection	Works locally	Events queued with no time limit until delivery possible
Incoming messages	Blocked	Arrive on next successful fetch