Field geology compass for iOS & Android

Measure the outcrop. Keep the whole record.

GeoCompass reads strike, dip, plunge and trend from your phone's sensors, then saves each measurement with coordinates, altitude, address and weather in one tap. Add photos, videos and notes on the spot, and export it all back at the desk.

Free to download · iPhone, iPad and Android · 10 languages

Plane

Strike · Azimuth · Dip · Dip direction

Line

Plunge · Trend

Coordinates

WGS84 · UTM · MGRS

How it works

Hold the phone against the structure. Read the numbers.

Diagram of a phone lying on a plane surface, showing strike, dip and dip direction — Plane

Lay the phone flat on the bedding, joint or fault surface to read strike, dip and dip direction.

01
Calibrate

Wave the phone in a figure eight to calibrate the magnetometer before you start.
02
Align

Choose Plane, Line or Coordinates, then place the device as shown above.
03
Lock & save

Lock freezes the reading so you can check it. Save stores it in the current project.
04
Document

Right after saving, take photos or videos and add notes, all attached to that measurement.

Features

Made for real fieldwork.

Every value you need sits on one screen, in large tabular numbers you can read in bright sun.

Plane & line attitude

Strike, azimuth, dip and dip direction for planes; plunge and trend for lines. A bubble level turns green when the device is level.

One-tap field record

Each save keeps the attitude with coordinates, altitude, horizontal accuracy, address, survey time and current weather.

Three coordinate systems

Show WGS84, UTM and MGRS side by side, or only the ones your survey uses.

Annotated photos

Stamp date, time, GPS and weather onto each photo in the colors you pick.

Separate projects

Create a project for each survey area or field trip, and keep its measurements apart from the rest.

Export everything

Export a project's measurements along with its photos and videos, ready for GIS or a stereonet.

Screens

One clear readout for every kind of measurement.

Plane mode reading strike N42°W, azimuth 318°, dip 36°NE and dip direction 48°, with WGS84 coordinates below — Plane

Get strike, azimuth, dip and dip direction for plane structures.

Line mode reading plunge 25° and trend 133°, with WGS84 coordinates and altitude below — Line

Get plunge and trend for line structures.

Coordinates mode showing WGS84 latitude and longitude, altitude 12 m, the street address and current weather of 13°C with few clouds — Coordinates Only

Support WGS84, UTM & MGRS coordinate systems.

Data Saved sheet for a line measurement of 33°/339°, with buttons to take photos, take videos or add notes — Saved

Attach photos, videos or notes right away.

Field record

Every measurement, fully documented.

See the day's work on the map, drawn as different symbols. The list keeps each measurement with its place, time, photos, videos and notes.

Tap a symbol on the map to preview the measurement and its photo
Sort by time or type in the list
Write notes inline, without leaving the list

Map view with saved measurements drawn as strike-and-dip and trend symbols; a preview card shows N64°E/48°NW with an outcrop photo

Measurement list with a plane, a line and a coordinates record, each with a photo thumbnail, photo and video counts and a notes field

AI assistant

Ask AI about the ground.

Pick a preset question and GeoCompass writes the prompt with your position filled in, then opens it in ChatGPT, Claude or Perplexity. Or copy it into any AI tool you like.

What geologic structures may exist here?
Are there active faults near this area?
What is the geologic age and lithology?
Which geohazards could occur here?

AI Assistant screen showing the target position's latitude and longitude above a numbered list of preset geology questions

10 languages

English · 繁體中文 · 简体中文 · 日本語 · Deutsch · Español · Français · Italiano · Português · Русский

Take GeoCompass to your next outcrop.

Free download on iPhone, iPad and Android.