Show the GPS Status.
GPS status includes: Not Installed, Disabled, No Fix/Invalid, Standalone
GPS Fix, Differential GPS Fix.
Not Installed: No GPS module inside.
Disabled: GPS function is not enabled (not click “Enable GPS” in item
“GPS Setting” yet).
No Fix/Invalid: GPS function is enabled, but do not get GPS signal (User
should put router outdoor to get stronger GPS signal).
Standalone GPS Fix: Standalone GPS techniques is a mature, universal
GPS positioning mode, only get position from satellite.
Differential GPS Fix: Differential GPS techniques are used to enhance the
quality of location data. It can be applied in real-time directly in the field
or when post processing data in the office.