gnss_scripts

Original Authors: CAO Shaozu (shaozu.cao AT gmail.com)

modifier: zzwu29

The gnss_comm package contains basic definitions and utility functions for GNSS raw measurement processing.

1. Prerequisites

1.1 C++11 Compiler

This package requires some features of C++11.

1.2 ROS

This package is developed under ROS Kinetic environment.

1.3 Eigen

Our code uses Eigen 3.3.3 for matrix manipulation. After downloading and unzipping the Eigen source code package, you may install it with the following commands:

cd eigen-3.3.3/
mkdir build
cd build
cmake ..
sudo make install

1.4 Glog

We use google's glog library for message output. If you are using Ubuntu, install it by:

sudo apt-get install libgoogle-glog-dev

If you are on other OS or just want to build it from source, please follow these instructions to install it.

2. Build gnss_comm library

Clone the repository to your catkin workspace (for example ~/catkin_ws/):

cd ~/catkin_ws/src/
git clone https://github.com/HKUST-Aerial-Robotics/gnss_comm.git

Then build the package with:

cd ~/catkin_ws/
catkin_make
source ~/catkin_ws/devel/setup.bash

If you encounter any problem during the building of gnss_comm, try with docker in the next section.

3. Docker Support

To simplify the building process, we add docker in our code. Docker is like a sandbox so it can isolate our code from your local environment. To run with docker, first make sure ros and docker are installed on your machine. Then add your account to docker group by sudo usermod -aG docker $USER. Relaunch the terminal or logout and re-login if you get Permission denied error, type:

cd ~/catkin_ws/src/gnss_comm/docker
make build

The docker image gnss_comm:latest should be successfully built after a while. Then you can check all available docker images in your local machine by docker image ls command.

4. Dataset Details

The dataset is released in the form of rosbag and currently there are two rosbags available:

name	duration	size	link
sports_field	25min	20.5GB	OneDrive
complex_environment	32min	26.1GB	OneDrive
urban_driving	41min	33.4GB	OneDrive

The data items within the rosbag are listed below:

topic	type	frequency	description
/cam0/image_raw	sensor_msgs/Image	20Hz	right camera
/cam1/image_raw	sensor_msgs/Image	20Hz	left camera
/imu0	sensor_msgs/Imu	200Hz	IMU
/external_trigger	gvins/LocalSensorExternalTrigger	-	publish when VI-Sensor is trigger. definition
/ublox_driver/receiver_lla	sensor_msgs/NavSatFix	10Hz	Receiver's GNSS solution (brief).
/ublox_driver/receiver_pvt	gnss_comm/GnssPVTSolnMsg	10Hz	Receiver's GNSS solution (verbose). definition
/ublox_driver/range_meas	gnss_comm/GnssMeasMsg	10Hz	GNSS raw measurement. definition
/ublox_driver/ephem	gnss_comm/GnssEphemMsg	-	The broadcast ephemeris of GPS, Galileo and BeiDou. definition
/ublox_driver/glo_ephem	gnss_comm/GnssGloEphemMsg	-	The broadcast ephemeris of GLONASS. definition
/ublox_driver/iono_params	gnss_comm/StampedFloat64Array	-	The broadcast ionospheric parameters. definition
/ublox_driver/time_pulse_info	gnss_comm/GnssTimePulseInfoMsg	1Hz	The time information of next PPS signal. definition.

5. Toolkit

The toolkit provided in this package requires gnss_comm library.

5.1. Convert GNSS raw measurement to RINEX File

cd ~/catkin_ws/
catkin_make
source devel/setup.bash
rosrun gvins_dataset_toolkit bag2rinex INPUT_BAG_FILEPATH OUTPUT_RINEX_FILEPATH

The observation RINEX file should be generated after a while. The corresponding GNSS ephemeris RINEX file can be found in GVINS-Dataset/data/ephemeris_rinex/.

5.2 Save RTK solution to csv file

cd ~/catkin_ws/
catkin_make
source devel/setup.bash
rosrun gvins_dataset_toolkit bag2rtk_solution INPUT_BAG_FILEPATH OUTPUT_RINEX_FILEPATH

Each record in the generated csv file is in the form of:

gnss_ts_ns, ecef_px, ecef_py, ecef_pz, enu_vx, enu_vy, enu_vz, fix_type, valid_fix, diff_soln, carr_soln

, with each item described in the following:

name	description
gnss_ts_ns	GNSS time of the navigation epoch (expressed as Unix timestamp in ns)
ecef_p*	The x, y, z component of the position in ECEF frame
enu_v*	The x, y, z component of the velocity in ENU frame
fix_type	GNSS fix type (0=no fix, 1=dead reckoning only, 2=2D-fix, 3=3D-fix, 4=GNSS+dead reckoning combined, 5=time only fix)
valid_fix	if fix valid (1=valid fix)
diff_soln	if differential correction were applied (1=applied)
carr_soln	carrier phase range solution status (0=no carrier phase, 1=float, 2=fix)

6. Acknowledgements

Many of the definitions and utility functions in this package are adapted from RTKLIB.

Project gnss_comm

Project GVINS-Dataset

7. License

The source code is released under GPLv3 license.