Navigate when the signal dies. Dead reckon it.
DEADRECKON turns a photo of a paper topographic map into a working navigation tool — calibrate it to its grid, drop your GPS on it, and measure grid azimuth and distance to your objective. Built to keep working when the cell signal doesn't.
Map Workspace
Photograph your topo map, calibrate it to the grid, then plot your GPS position and shoot azimuths with the digital protractor.
Compass & Azimuth
Live magnetic compass plus grid⇄magnetic conversion, back azimuth, and mils — the declination math done for you.
Coordinates & Pace
Read your position as MGRS, UTM, and lat/long. Track pace count and leg distance as you move.
Field Reference
Quick-reference card distilled from TC 3-25.26 (Map Reading and Land Navigation): azimuths, terrain features, resection, intersection.
How a typical fix works
- 1Photograph & calibrate
Snap your topo map. Tap two grid-line intersections and type their grid coordinates. The app locks the photo to the real-world grid.
- 2Find yourself
Hit GPS. Your position drops onto the photo. No grid lines on your map? Resection from two known features instead.
- 3Shoot the azimuth
Tap your position, then your objective. Read the grid azimuth, the magnetic azimuth to set on your compass, and the distance.
Field note. A phone is a supplement to — not a replacement for — a real map, a real lensatic compass, and the skills to use them. Batteries die, magnetometers drift near metal and vehicles, and GPS lies in canyons. Always carry and know how to use the analog tools. Southern Utah backcountry is unforgiving.