Update docs

docs/UsingInRos.md

@@ -2,8 +2,8 @@
 
 If you want to use norlab_icp_mapper in [ROS](http://www.ros.org/) or [ROS 2](https://docs.ros.org/en/jazzy/index.html), you can will need to install few more dependencies:
 
-+ [libpointmatcher_ros](https://github.com/norlab-ulaval/libpointmatcher_ros) allows the conversion of pointclouds from ROS message formats to a libpointmatcher-compatible format.
-+ [norlab_icp_mapper_ros](https://github.com/norlab-ulaval/norlab_icp_mapper_ros) is a bridge between the mapper and ROS and provides a mapping node that is already functional and that can be customized using YAML configuration files to suite your needs.
+- [libpointmatcher_ros](https://github.com/norlab-ulaval/libpointmatcher_ros) allows the conversion of pointclouds from ROS message formats to a libpointmatcher-compatible format.
+- [norlab_icp_mapper_ros](https://github.com/norlab-ulaval/norlab_icp_mapper_ros) is a bridge between the mapper and ROS and provides a mapping node that is already functional and that can be customized using YAML configuration files to suite your needs.
 
 ## Tutorial
 
@@ -15,72 +15,74 @@ Assuming you completed the [Example: building a map from lidar scans](RunningExa
 Download the demonstration data using:
 
 === "ROS"
-    TODO
+TODO
 
 === "ROS 2"
-    ```shell
+`shell
     cd ~/
     wget -O demo.zip "http://norlab.s3.valeria.science/demo.zip?AWSAccessKeyId=XMBLP3A0338XN5LASKV2&Expires=2290342833&Signature=NXn1f%2BeJ7NptrzUkNzHtEvdicjc%3D"
     unzip demo.zip
     rm demo.zip
-    ```
+    `
 
 ### Fetching libpointmatcher_ros
 
 === "ROS"
-    ```shell
+`shell
     cd ~/
     mkdir -p catkin_ws/src && cd catkin_ws/src/
     git clone -b melodic https://github.com/norlab-ulaval/libpointmatcher_ros.git
-    ```
+    `
 
 === "ROS 2"
-    ```shell
+`shell
     cd ~/
     mkdir -p ros2_ws/src && cd ros2_ws/src/
     git clone https://github.com/norlab-ulaval/libpointmatcher_ros.git
-    ```
+    `
 
 ### Fetching norlab_icp_mapper_ros
+
 === "ROS"
-    ```shell
+`shell
     cd ~/catkin_ws/src/
     git clone -b melodic https://github.com/norlab-ulaval/norlab_icp_mapper_ros.git
-    ```
+    `
 
 === "ROS 2"
-    ```shell
+`shell
     cd ~/ros2_ws/src/
     git clone https://github.com/norlab-ulaval/norlab_icp_mapper_ros.git
-    ```
+    `
 
 ### Fetching mapper_config_template
+
 === "ROS"
-    ```shell
+`shell
     cd ~/catkin_ws/src/
     git clone -b melodic https://github.com/norlab-ulaval/mapper_config_template.git
-    ```
+    `
 
 === "ROS 2"
-    ```shell
+`shell
     cd ~/ros2_ws/src/
     git clone https://github.com/norlab-ulaval/mapper_config_template.git
-    ```
+    `
 
 ### Compiling ros workspace
 
 === "ROS"
-    ```shell
+`shell
     cd ~/catkin_ws/
     catkin_make
-    ```
+    `
 
 === "ROS 2"
-    ```shell
+`shell
     cd ~/ros2_ws/
     colcon build --symlink-install
     source ~/ros2_ws/install/setup.bash
-    ```
+    `
 
 ### Mapping basics
 
@@ -97,10 +99,10 @@ ensure good localization at all times.
 
 The mapper configuration template `params/config.yaml` contains four important sections :
 
-* ICP parameters used by libpointmatcher to do the registration of new point clouds in the map.
-* Input filters which are applied to the new point clouds before being processed.
-* Post-processing filters which are applied to the map after adding the new point cloud.
-* Mapper parameters that configure the mapper's update condition and MapperModules.
+- ICP parameters used by libpointmatcher to do the registration of new point clouds in the map.
+- Input filters which are applied to the new point clouds before being processed.
+- Post-processing filters which are applied to the map after adding the new point cloud.
+- Mapper parameters that configure the mapper's update condition and MapperModules.
 
 See [How to configure the Mapper](MapperConfiguration.md) guide for more details.
 
@@ -112,20 +114,20 @@ Finally, the ROS launch file is located in `launch/mapper.launch` for ROS and `l
 ### Running the demo
 
 === "ROS"
-    ```shell
+`shell
     roscore
     rosparam set use_sim_time true
     roslaunch mapper_config_template mapper.launch
     rviz -d ~/demo/config.rviz
     rosbag play ~/demo/demo.bag --clock --keep-alive
-    ```
+    `
 
 === "ROS 2"
-    ```shell
+`shell
     ros2 launch mapper_config_template mapper.launch.py
     rviz2 -d ~/demo/config.rviz
     ros2 bag play ~/demo/demo --clock
-    ```
+    `
 
 ![Final map](images/ros_trajectory.png)
 
@@ -134,19 +136,20 @@ Finally, the ROS launch file is located in `launch/mapper.launch` for ROS and `l
 #### Lowering the map density
 
 Open the file `mapper.config` and change the following parameter:
+
 ```yaml
-   PointDistanceMapperModule:
-      minDistNewPoint: 0.1 -> 1.0
+PointDistanceMapperModule:
+  minDistNewPoint: 0.1 -> 1.0
 ```
 
 #### Changing the map update condition
 
 Open the file `mapper.config` and change the following parameters:
 
 ```yaml
-   updateCondition:
-    type: overlap -> distance
-    value: 0.5 -> 1.0
+updateCondition:
+  type: overlap -> distance
+  value: 0.5 -> 1.0
 ```
 
 #### Removing points reflected from the robot's chassis
@@ -170,13 +173,13 @@ Open the file `mapper.config` and add the following lines in the `input` section
 
 ```yaml
 - BoundingBoxDataPointsFilter:
-      xMin: -6
-      xMax: -1.5
-      yMin: -2.5
-      yMax: 2.5
-      zMin: -1
-      zMax: 1
-      removeInside: 1
+    xMin: -6
+    xMax: -1.5
+    yMin: -2.5
+    yMax: 2.5
+    zMin: -1
+    zMax: 1
+    removeInside: 1
 ```
 
 #### Removing dynamic points
@@ -194,29 +197,69 @@ Open the file `mapper.config` and add the following lines in the `post` section:
 ```
 
 Then change the following MapperModule in the `mapperModule` portion of the `mapper` section:
+
 ```yaml
-    DynamicPointsMapperModule:
-      thresholdDynamic: 0.65
-      alpha: 0.2
-      beta: 0.99
-      beamHalfAngle: 0.01
-      epsilonA: 0.01
-      epsilonD: 0.01
+DynamicPointsMapperModule:
+  thresholdDynamic: 0.65
+  alpha: 0.2
+  beta: 0.99
+  beamHalfAngle: 0.01
+  epsilonA: 0.01
+  epsilonD: 0.01
+```
+
+#### Deskewing the input point cloud
+
+Unlike the other mapping modueles, deskewing is part of the ROS 2 wrapper `norlab_icp_mapper_ros'.
+This is due to the fact that deskewing requires TF2 interpolations which must happen inside the ROS ecosystem.
+To enable deskewing, set the `deskew`parameter to`true`in the`mapper.launch.py` file.
+Moreover, you can adjust the deskewing behavior by changing these two parameters:
+
+- `expected_unique_deskewing_TF_number`: defines the number of unique TFs that are expected to be used for deskewing. This number is used to prealocated memory space in a hash map and while an incorrect value might cause slowdowns, it is not that important.
+- `deskewing_round_to_nanosecs`: defines the time resolution at which the deskewing TFs are rounded. This is used to reduce the number of TFs that are queried from the TF buffer. A value of 50000 means that the TFs are rounded to the nearest 50 microseconds.
+
+`````yaml
+
+````python
+    deskew = True
+
+```yaml
+- SurfaceNormalDataPointsFilter:
+    knn: 10
+
+- CutAtDescriptorThresholdDataPointsFilter:
+    descName: probabilityDynamic
+    useLargerThan: 1
+    threshold: 0.65
+`````
+
+Then change the following MapperModule in the `mapperModule` portion of the `mapper` section:
+
+```yaml
+DynamicPointsMapperModule:
+  thresholdDynamic: 0.65
+  alpha: 0.2
+  beta: 0.99
+  beamHalfAngle: 0.01
+  epsilonA: 0.01
+  epsilonD: 0.01
 ```
 
 #### Saving the map
+
 You can save the map by calling the `/save_map` service. Similarly, use the `/save_trajectory` service to save the trajectory.
 === "ROS"
-    ```shell
+`shell
     rosservice call /save_map "map_file_name:
         data: '$HOME/demo/demo.vtk'"
-    ```
+    `
 
 === "ROS 2"
-    ```shell
+`shell
     ros2 service call /save_map norlab_icp_mapper_ros/srv/SaveMap "{map_file_name: {data: '$HOME/demo/demo.vtk'}}"
-    ```
+    `
 
 ### Final Result
+
 You can visualize the final result in [ParaView](https://www.paraview.org/) or other point cloud viewer of your choice.
 ![Final map](images/ros_map.png)