Chapter 6 Deploying Wireless Networks for FortiOS 5.0 : Support for location-based services : Viewing device location data on the FortiGate unit
  
Viewing device location data on the FortiGate unit
You can use the FortiGate CLI to list located devices. This is mainly useful to confirm that the location data feature is working, You can also reset device location data.
To list located devices
diag wireless-controller wlac -c sta-locate
To reset device location data
diag wireless-controller wlac -c sta-locate-reset