DGPS

The Differential GPS present here is based on the Ublox chip M8P. There are two types of Ublox M8P:

• NEO-M8P-0: acting as the rover (mobile)
• NEO-M8P-2: acting as the rover (mobile) or as the ground station

The NEO-M8P-2 acting ground station should know its position. This can be done by locating the ground antenna to a know position and initializing the ublox to this position, or programming the ublox to send its estimate converging position after a given time and giver precision

The as a ground station acquire observation data from its fixed position and output these data to the NEO-M8P rover (mobile).

can be initialized with a know position, or programed to converge within a given time and precision.

This way the ground station transmits also its position. The DGPS use three messages typed from RTCM3 standard protocol: - RTCM3.2 1005 : Ground station position - RTCM3.2 1077 : GPS observation data - RTCM3.2 1087 : Beidou observation data

as well as its position. The ground station The NEO-M8P acting as a rover (mobile) computes the position of the ground station acquire observation data from its mobile position and These data are transmitted as new messages within the paparazzi telemetry. The