RTK Parser ROS2 Package

Overview

RTK Parser is a ROS2 package designed to parse and analyze RTCM messages for RTK (Real-Time Kinematic) positioning systems. It provides comprehensive analysis of RTCM data, baseline distance calculations, signal quality monitoring, and satellite tracking capabilities.

Features

• Parse various RTCM message types (1001-1230)
• Calculate baseline distance between base station and rover
• Monitor satellite signal quality and count
• Provide diagnostic information
• Support multiple GNSS constellations (GPS, GLONASS, Galileo, BeiDou)
• Real-time position tracking for both base station and rover

Supported RTCM Messages

Message Type	Description
1001-1004	GPS RTK Observables
1005-1006	Station Coordinates
1007	Antenna Descriptor
1009-1012	GLONASS RTK Observables
1033	Receiver and Antenna Description
1074-1077	GPS MSM4-7
1084-1087	GLONASS MSM4-7
1094-1097	Galileo MSM4-7
1124-1127	BeiDou MSM4-7
1230	GLONASS Code-Phase Biases

Installation

Prerequisites

• ROS2 (Tested on Humble)
• Python 3.8+
• pip
• rtk_interfaces - Custom message definitions for RTK data

Dependencies

sudo apt-get update
sudo apt-get install -y \
    python3-pip \
    python3-numpy \
    ros-humble-diagnostic-msgs \
    ros-humble-mavros-msgs \
    ros-humble-nmea-msgs

pip3 install pyrtcm geographiclib

Building from Source

# Create a workspace (if you don't have one)
mkdir -p ~/ros2_ws/src
cd ~/ros2_ws/src

# First, clone and build rtk_interfaces
git clone https://github.com/yourusername/rtk_interfaces.git

# Then clone this repository
git clone https://github.com/yourusername/rtk_parser.git

# Install dependencies
cd ~/ros2_ws
rosdep install --from-paths src --ignore-src -r -y

# Build the packages (order matters)
colcon build --packages-select rtk_interfaces
colcon build --packages-select rtk_parser

# Source the workspace
source ~/ros2_ws/install/setup.bash

Usage

Launch the Node

ros2 launch rtk_parser rtk_parser.launch.py

With debug output enabled:

ros2 launch rtk_parser rtk_parser.launch.py debug:=true

Published Topics

Topic Name	Message Type	Description
/rtcm_parser/base_position	sensor_msgs/NavSatFix	Base station position
/rtcm_parser/rover_position	sensor_msgs/NavSatFix	Rover position
/rtcm_parser/baseline_status	rtk_parser/BaselineStatus	Baseline information
/rtcm_parser/gnss_status	rtk_parser/GNSSStatus	GNSS system status
/rtcm_parser/satellite_info	rtk_parser/Satellite	Individual satellite information
/rtcm_parser/rtk_diagnostics	diagnostic_msgs/DiagnosticArray	System diagnostics

Subscribed Topics

Topic Name	Message Type	Description
/rtcm	mavros_msgs/RTCM	RTCM messages from base station
/nmea	nmea_msgs/Sentence	NMEA messages from rover

Monitor Topics

# Monitor baseline status
ros2 topic echo /baseline_status

# Monitor GNSS status
ros2 topic echo /gnss_status

# Monitor diagnostics
ros2 topic echo /rtk_diagnostics

Custom Messages

This package uses custom message types defined in the rtk_interfaces package. Please ensure you have this package installed.

BaselineStatus

std_msgs/Header header
float64 distance_3d
float64 distance_2d
float64 height_difference
sensor_msgs/NavSatFix base_position
sensor_msgs/NavSatFix rover_position
uint8 satellite_count
float32 average_snr
string rtk_status

GNSSStatus

std_msgs/Header header
uint8 satellite_count
float32[] snr_values
uint16[] rtcm_msg_ids
string[] satellite_systems
string coordinate_system

Satellite

std_msgs/Header header
string satellite_id
float32 carrier_phase
float32 pseudorange
float32 doppler
float32 snr
uint8 lock_time_indicator
bool half_cycle_valid

Configuration

The node can be configured through ROS2 parameters or launch file arguments. See the launch file for available options.

Troubleshooting

Common issues and solutions:

1. No RTCM messages received

   • Check your RTCM source connection
   • Verify the /rtcm topic is being published
   • Check message rates and baud rates

2. No baseline calculation

   • Ensure both base position and rover position are being received
   • Check NMEA message format and parsing