Professional-grade tools for elevation measurement and data collection
Real-time altitude measurement using your device's GPS receiver. Get instant elevation data anywhere with a clear view of the sky. Works worldwide without requiring calibration or internet connection.
One-touch automatic calibration using USGS National Map elevation data. The app queries ground-truth elevation at your location and calibrates your device's barometer for improved accuracy. Calibrate once, measure all day.
Record elevation measurements with timestamps, coordinates, and sensor readings. Export complete datasets to CSV format for analysis in Excel, Google Sheets, R, Python, MATLAB, or GIS software. Perfect for research documentation and student projects.
Works in remote field locations without internet access. GPS-only mode provides elevation anywhere, and manual calibration lets you set a known elevation for improved barometric accuracy when offline.
Leverages authoritative USGS elevation data for ground-truth calibration. GPS typically provides ±10-20 meter accuracy; calibrated barometer can achieve ±1-3 meter accuracy depending on atmospheric conditions.
Clean, focused interface designed for fieldwork. No accounts, no login, no setup required. Launch the app and start measuring immediately. All controls and readings visible on one screen.
Built on authoritative data sources and proven sensor technologies
USGS National Map Elevation Point Query Service (EPQS) - authoritative ground elevation data covering the entire United States, Alaska, Hawaii, Puerto Rico, and U.S. territories.
GPS: ±10-20 meters typical
Calibrated Barometer: ±1-3 meters (conditions dependent)
Best Results: Clear sky, stable weather, recent calibration
Built-in GPS receiver for location and altitude, barometric pressure sensor for precise relative elevation changes, USGS ground elevation data for absolute calibration reference.
iOS 14.0 or later. Compatible with iPhone and iPad devices with GPS capability. Internet connection required only for USGS calibration (offline mode available).
Zero data collection. Location used only for real-time measurement. No tracking, no analytics, no third-party services. Your measurements stay on your device.
Works best outdoors with clear sky view for GPS. Barometer calibration takes 30-60 seconds. Most accurate in stable weather conditions. Can be used indoors after outdoor calibration.