Altitude

Altitude as provided by GPS is rather inaccurate.
Ultra GPS Logger has several options to compensate for that fact.
If an altitude correction method is in use, the main screen will show the uncorrected altitude first, followed by the corrected altitude.
Only the corrected altitude will be recorded in the GPX/KML track, and the track summary section records correction method and reference.

Altitude Offset

Altitude Offset

You can specify a local offset which is used to correct GPS altitude.

Get Current Altitude

Gets current altitude and uses it as new offset. Basically calibrates the altitude reading to 0.

Reset Altitude

Use raw reading without offset. Resets the altitude offset to 0.

Pressure Sensor / Barometer

If your device has a barometric pressure sensor it can be used to correct the GPS altitude.

Use pressure sensor

Use pressure readings to compensate altitude.

Pressure reference

Reference used for calculation. Defaults to STANDARD_ATMOSPHERE = 1013.25hPa/mb.

Get pressure

Gets pressure reference reading from local weather station.

Get pressure by altitude

Calculates pressure reference based on altitude reference; enter current altitude in meters.

Reset

Reset pressure reference to STANDARD_ATMOSPHERE = 1013.25hPa/mb.