From GPS Coordinates to Screen Pixels: The Full AR Projection Math

The article walks through projecting an aircraft’s GPS position onto an Android AR camera view by chaining multiple coordinate transforms.

It converts geodetic coordinates into ENU, then into device and camera frames, and finally into screen pixels via perspective projection.

Correct axis conventions and sign handling are emphasized as the key to avoiding subtle but serious overlay errors.

This is especially useful for developers building ADS-B or GPS-based AR overlays on Android.

A small math or orientation mistake can make an overlay look plausible while landing in the wrong place on screen.