Setup guide for RTK support

This configuration guide explains RTK support options for any outdoor drone show.

RTK support for locally connected RTK base stations and external RTK correction sources is handled in Skybrush Server by the rtk extension. The following guide shows some of the most important configuration options of the rtk extension.

Autodetecting locally connected RTK base stations

If you use a local RTK base station that is connected to the computer running Skybrush Server with a USB cable, that appears in your system as an UART/serial port with a baud rate of lets say 57600, then you should have this line in your .jsonc configuration file in the EXTENSIONS property of the main JSON object to autodetect your RTK base station:

    "rtk": {
      "add_serial_ports": [57600]
    },

You can add more possible baud rates into the list, if needed. Also consider using the exclude_serial_ports or exclude_non_rtk_base properties to filter the list of possible RTK devices appearing in the RTK dialog of Skybrush Live even more.

Configuring external NTRIP sources

You also have the option to configure external NTRIP sources providing correction data instead of your local RTK base station. For this, you need to use the presets property, such as in the example below:

    "rtk": {
      "add_serial_ports": [57600],
      "presets": [
        "hires-msm-test": {
            "title": "High resolution RTK MSM test",
            "source": "ntrip://rtk2go.com/AgPartner_1"
            "filter": {
                "reject": ["rtcm3/1007", "rtcm3/1019"]
            }
        }
      ]
    },

title: The given title will appear in Skybrush Live in the list of RTK sources.
source: The source string parameter points to the given NTRIP source. This should be a standard connection string, containing the type of source (starting with ntrip://, tcp://, serial:// etc.), the url, IP address and optional port, and optional login information. Contact your NTRIP data provider for the accurate connection string you have to use for a given source.
filter: The filter property can be used to reject certain RTCM message types not needed from a given RTK source, if they just flood the communication channel but do not transmit relevant information needed for the drones. Note that RTCM streams can occupy high bandwidth, the more required filters you apply, the less connectivity problems you will have.

Predefining the position of your RTK base station

You also have the option to provide a fixed ECEF coordinate to your RTK extension to skip auto survey at powerup and use a fixed, previously accurately measured coordinate instead. For this, use the fixed property, such as in the example below:

    "rtk": {
      "add_serial_ports": [57600],
      "fixed": {
        "position": [4120404.12, 1418769.34, 4641911.56],
        "accuracy": 0.8
      }
    }

Do not forget that the coordinates should be Earth-Centered, Earth-Fixed (ECEF), not WGS84 (latitude, longitude, altitude)!

Additional options

There are several other options for configuring your RTK base, such as filtering GNSS types, configuring auto-survey behaviour, or enabling Skybrush Live to show the RTK base station location on the map. For a full list of properties see the auto-generated documentation of the rtk extension.