C_RTK 9Ps User guide(for PX4)
Real Time Motion (RTK) increases the accuracy of GNSS/GPS systems to the centimeter level. C-RTK 9Ps makes PX4 suitable for precision measurement fields such as precision measurement.
set up C-RTK 9Ps（Base）
- Use a tripod to mount the base station's antenna to the top, and connect the antenna to the base station
- Connect the base station and telemetry to the computer with a usb cable.
- Run the Missionplanner/Qgroundcontrol program.
set up C-RTK 9Ps（Rover）
- Use a tripod to elevate the antenna on the base station side, and use a feeder to connect the antenna and the base station side.
- Use a USB cable to connect the base station and data transmission to the computer
- QGroundControl starts the RTK setup process (called "Entering Survey").
- Entering a survey is the initiation procedure to obtain an accurate location estimate of the base station. This process usually takes some time (ends after reaching the minimum time and precision specified in the RTK settings). You can track your progress by clicking the GPS status icon
When the C-RTK 9Ps device is connected (in addition to the normal GPS status icon), the GPS status icon will be displayed in the top icon bar. When setting up RTK, the icon is red, and once the RTK GPS is in the survey complete state, the icon will turn white.
You can click the icon to view the current status and RTK accuracy.
After the survey is complete: the gps icon turns white and QGroundControl starts to transmit position data to the aircraft:
The aircraft GPS is switched to RTK mode. The new mode is shown in the normal GPS status icon (3D RTK GPS fix):
Optional PX4 configuration
The following settings may need to be changed (using QGroundControl).
C-RTK 9Ps GPS settings
C-RTK 9P GPS settings are specified in QGroundControl General Settings (SettingsView 》 General Settings)
These settings define the minimum duration (should be set to 40s or less) and minimum accuracy (recommended setting of 2.5) to complete the C-RTK GPS setup process.
MAVLink2 protocol must be used because it can use lower bandwidth channels more efficiently. This should be enabled by default in recent builds.
To make sure MAVLink2 is used:
- MAV_PROTO_VER set to2
You may also need to adjust some parameters, as the default parameters are adjusted to an accuracy of meters, not centimeters. For example, you can reduce EKF2_GPS_V_NOISE and EKF2_GPS_P_NOISE to 0.2.