This page list GPS and compass devices compatible with Elphel cameras.

GPS

External

Garmin GPS18 is the model we sell by default with our GEO cameras.
Garmin GPS 20x is also supported.
USGlobalSat EM-406A SiRF III can be used with Arduino and GPS Shield. (some minor tweaking of the firmware is needed)

Compass is used for camera orientation, so only internal compass make sens.

We use an Ocean 5000 compass that is mounted inside the camera and connected to the internal USB port on the 10369 board.