The altimeter shows height above sea level from two sources.
Access: Position tab → altimeter tile.
- GPS — altitude from satellite signal (slower to react, depends on signal quality)
- Barometer — atmospheric pressure from the phone sensor (faster reaction, requires a barometer)
Barometric data may be calibrated against GPS altitude on first read.
Uses
- Rough altitude check in a mountain harbour
- Watching pressure trend (approaching weather change)