RTK and NTRIP corrections¶
The MS2-net achieves centimetre-level accuracy through RTK (Real-Time Kinematic): the ZED-F9P module combines its own measurements with RTCM 3.x differential corrections coming from a base or from a network of permanent reference stations.
Corrections can arrive over Ethernet or WiFi (NTRIP client), or be generated by the receiver itself when it works as a base.
Rover mode (NTRIP client)¶
In rover mode, the MS2-net receives corrections from an NTRIP caster and applies them to obtain an RTK fix.
- Enter the NTRIP caster credentials (host, port, mountpoint, user, password) in the configuration.
- Place the antenna with a clear view of the sky.
- The receiver acquires satellites and, in good conditions, reaches RTK fixed (centimetre-level accuracy).
| RTK status | Meaning |
|---|---|
| No fix / 3D | Standard GNSS position (metres). |
| RTK float | Corrections applied, ambiguities not yet resolved (decimetres). |
| RTK fixed | Ambiguities resolved: centimetre-level accuracy. |
Base mode¶
In base mode, the MS2-net stays fixed on a point and generates RTCM corrections to be distributed to rovers. The base can operate in two ways:
| Base mode | Description |
|---|---|
| Survey-in | The base determines its own position by averaging measurements for a set time/accuracy, then starts transmitting. |
| Fixed coordinates | The known position of the base is entered directly (more accurate and immediate if the coordinates are known). |
Distributing corrections (NTRIP server) --------------------------------------------
The corrections generated by the base can be:
- sent to an NTRIP caster (NTRIP server) so that other rovers can download them over the Internet;
- distributed over the LAN using the Ethernet port (see
ethernet), useful for permanently installed bases.
Assisted survey-in¶
The MS2 firmware supports an assisted mode in which the base performs the survey-in while it is being fed corrections, combining the rover and base roles during the initial phase, to converge more quickly on reliable coordinates. (detailed parameters depend on the configuration)