Geoid Altimeter -Elevation,DEM

Geoid Altimeter is an elevation tracking tool built for field professionals. It applies high-precision geoid models to your smartphone's GPS ellipsoidal height to display a practical "orthometric height" (elevation above mean sea level).

Try all features completely free for the first 30 days. Experience the convenience directly on your smartphone.

[ Key Features ]
- Orthometric Height (H = h − N): Converts the raw GPS ellipsoidal height using national or global geoid models.
- High-Resolution Elevation (DEM): Reads terrain elevation for your current location or any pinned point — no need to physically stand there.
- Pin & Address Search: Drop a pin or search an address to check the elevation anywhere on the map.
- Favorites & CSV Export: Save sites with custom names and export all values (h, N, H, DEM) as CSV.
- Model Comparison: View your local model alongside the global EGM96 reference.
- One-Tap Copy, Screenshot Share, Transparent Satellite/OSM Overlay, and Compass.

[ Supported High-Precision Regions ]

Geoid models (orthometric height correction):
Japan (Geoid 2024 / GSI), United States (GEOID18 / NOAA-NGS), Canada (CGG2013a / NRCan), New Zealand (NZGeoid2016 / LINZ), Switzerland (CHGeo2004 / swisstopo).

High-resolution elevation (DEM):
Japan (GSI, 5 m laser mesh), United States (USGS 3DEP), Switzerland (swisstopo), France (IGN RGE ALTI, 1 m).

For every other country and region, the app provides seamless worldwide coverage using the global EGM96 geoid and global terrain-elevation data.

[ New in 1.4.0 ]
- Works beyond coverage: pre-load the national geoid model around you, and elevations stay on that model when the network goes.
- Always says which model answered — the national service live, a value saved nearby, or the global EGM96 standing in.
- Stand-still averaging: hold still and get a mean with its spread, instead of a single fix that scatters by metres.
- Antenna height: set the pole length or how high you hold the phone, and it is subtracted from every GNSS height.
- Height difference and grade (% and 1:n) between two saved points, a one-page PDF elevation record, and NGVD29 readings for US drawings levelled before NAVD88.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/