README

ROS NTRIP Client

Description

ROS node that will communicate with an NTRP caster to receive RTCM connections and publish them on a ROS topic. Also works with virtual NTRIP servers by subscribing to NMEA messages and sending them to the NTRIP server

Important Branches

There are two important branches that you may want to checkout:

ros – Contains ROS1 implementation for this node.
ros2 – Contains ROS2 implementation for this node.

Build Instructions

Building from source

Install ROS2 and create a workspace: Installing and Configuring Your ROS2 Environment
Move the entire ntrip_client folder to the your_workspace/src directory.
Install rosdeps for this package: rosdep install --from-paths ~/your_workspace/src --ignore-src -r -y
Build your workspace:
```
cd ~/your_workspace
colcon build
source ~/your_workspace/install/setup.bash
```
The source command may need to be run in each terminal prior to launching a ROS node.

Connect to a NTRIP caster or server

This is useful if you have access to an NTRIP caster or server that you want to connect to over the internet.

ros2 launch ntrip_client ntrip_client_launch.py

Optional launch parameters:

host: Hostname or IP address of the NTRIP server to connect to.
port: Port to connect to on the server. Default: 2101
mountpoint: Mountpoint to connect to on the NTRIP server.
ntrip_version: Value to use for the Ntrip-Version header in the initial HTTP request to the caster.
authenticate: Whether to authenticate with the server, or send an unauthenticated request. If set to true, username, and password must be supplied.
username: Username to use when authenticating with the NTRIP server. Only used if authenticate is true
password: Password to use when authenticating with the NTRIP server. Only used if authenticate is true
ssl: Whether to connect with SSL. cert, key, and ca_cert options will only take effect if this is true
cert: If the NTRIP caster is configured to use cert based authentication, you can use this option to specify the client certificate
key: If the NTRIP caster is configured to use cert based authentication, you can use this option to specify the private key
ca_cert: If the NTRIP caster uses self signed certs, or you need to use a different CA chain, this option can be used to specify a CA file
rtcm_message_packege: Changes the type of ROS RTCM message published by this node. Defaults to mavros_msgs, but also supports rtcm_msgs

Connect to a NTRIP “device”

This is useful if you do not have an internet connection, but do have an NTRIP “device” that you want to receive connections from, such as the MicroStrain 3DM-RTK.

ros2 launch ntrip_client ntrip_serial_device_launch.py

Optional launch parameters:

port: Serial port that the device is connected on.
baudrate: Baudrate to connect to the serial port at. Default 115200
rtcm_message_packege: Changes the type of ROS RTCM message published by this node. Defaults to mavros_msgs, but also supports rtcm_msgs

Topics

This node currently only has three topics of interest:

/rtcm: This node will publish the RTCM corrections received from the server to this topic as RTCM messages. These messages can be consumed by nodes such as the microstrain_inertial_driver
- NOTE: The type of message can be switched between mavros_msgs/RTCM and rtcm_msgs/Message using the rtcm_message_package parameter
/nmea: This node will subscribe on this topic and receive NMEA sentence messages which it will forward to the NTRIP server. This is always needed when using a virtual NTRIP server or an NTRIP device
/fix: This serves the same exact purpose as /nmea, but facilitates receiving global position that is not in NMEA format

License

ntrip_client is released under the MIT License - see the LICENSE file in the source distribution.