1. Support GR-9029/GR-9028 Bluetooth LE GNSS receiver
2. App receive correction data from reference station and forward to receiver.
3. Receiver calculate the data and decide it's precision position, then send GGA to App
4.Finally App draw the position in map.

App is a utility tool for testing the receiver.
a.Relative position measurement
GR-9029 have a button in it.
User press the button ,then App will draw a pin in map.
When user press again , the App draw a new pin and show the distance between two pin (If "distance measurement" function is enable)
b. Absolute position measurement.
Receiver is placed on a known position. User can compare the known position with the coordinate show in map.
c.Benchmark with other receiver
App support "Log" function , it can record entire path .
User can compare the path with others and check the deviation