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Converting UTM maps to MGRS map format#

Overview#

If you want to use MGRS (Military Grid Reference System) format in Autoware, you need to convert UTM (Universal Transverse Mercator) map to MGRS format. In order to do that, we will use UTM to MGRS pointcloud converter ROS 2 package provided by Leo Drive.

Installation#

Dependencies#

To install dependencies:

sudo apt install ros-humble-pcl-conversions \
       geographiclib-tools

Building#

    cd <PATH-TO-YOUR-ROS-2-WORKSPACE>/src
    git clone https://github.com/leo-drive/pc_utm_to_mgrs_converter.git
    cd ..
    colcon build --symlink-install --cmake-args -DCMAKE_BUILD_TYPE=Release

Usage#

After the installation of converter tool, we need to define northing, easting and ellipsoid height of local UTM map origin in pc_utm_to_mgrs_converter.param.yaml. For example, you can use latitude, longitude and altitude values in the navsatfix message from your GNSS/INS sensor.

Sample ROS 2 topic echo from navsatfix message 
header:
stamp:
sec: 1694612439
nanosec: 400000000
frame_id: GNSS_INS/gnss_ins_link
status:
status: 0
service: 1
latitude: 41.0216110801253
longitude: 28.887096461148346
altitude: 74.28264078891529
position_covariance:
- 0.0014575386885553598
- 0.0
- 0.0
- 0.0
- 0.004014162812381983
- 0.0
- 0.0
- 0.0
- 0.0039727711118757725
position_covariance_type: 2

After that, you need to convert latitude and longitude values to northing and easting values. You can use any converter on the internet for converting latitude longitude values to UTM. (i.e., UTMconverter)

Now, we are ready to update pc_utm_to_mgrs_converter.param.yaml, example for our navsatfix message:

/**:
  ros__parameters:
      # Northing of local origin
-     Northing: 4520550.0
+     Northing: 4542871.33

      # Easting of local origin
-     Easting: 698891.0
+     Easting: 658659.84

      # Elipsoid Height of local origin
-     ElipsoidHeight: 47.62
+     ElipsoidHeight: 74.28

Lastly, we will update input and pointcloud the map path in pc_utm_to_mgrs_converter.launch.xml:

...
- <arg name="input_file_path" default="/home/melike/projects/autoware_data/gebze_pospac_map/pointcloud_map.pcd"/>
+ <arg name="input_file_path" default="<PATH-TO-YOUR-INPUT-PCD-MAP>"/>
- <arg name="output_file_path" default="/home/melike/projects/autoware_data/gebze_pospac_map/pointcloud_map_mgrs_orto.pcd"/>
+ <arg name="output_file_path" default="<PATH-TO-YOUR-OUTPUT-PCD-MAP>"/>
...

After the setting of the package, we will launch pc_utm_to_mgrs_converter:

ros2 launch pc_utm_to_mgrs_converter pc_utm_to_mgrs_converter.launch.xml

The conversion process will be started, you should see Saved <YOUR-MAP-POINTS-SIZE> data points saved to <YOUR-OUTPUT-MAP-PATH> message on your terminal. MGRS format pointcloud map should be saved on your output map directory.