Update configuring-collision-monitor-node.rst (#796)

* Update configuring-collision-monitor-node.rst

Changes to support issue 5585 from the nav2 repo.

Signed-off-by: Greg Anderson <107634795+greganderson-vermeer@users.noreply.github.com>

* Update configuration/packages/collision_monitor/configuring-collision-monitor-node.rst

Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>

---------

Signed-off-by: Greg Anderson <107634795+greganderson-vermeer@users.noreply.github.com>
Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>
Co-authored-by: Steve Macenski <stevenmacenski@gmail.com>

Author: greganderson-vermeer

configuration/packages/collision_monitor/configuring-collision-monitor-node.rst

@@ -573,6 +573,17 @@ Observation sources parameters
   Description:
     Maximum height the PointCloud projection to 2D space ended with. Applicable for ``pointcloud`` type.
 
+:``<source name>``.use_global_height:
+
+  ============== =============================
+  Type           Default
+  -------------- -----------------------------
+  bool           false
+  ============== =============================
+
+  Description:
+    Set true for pointcloud sources containing a "height" field relative to a real world ground contour. The "height" field will be used for the min and max height checks instead of the "z" field and will not be transformed as it is assumed that height is already global frame referenced. Applicable for ``pointcloud`` type.
+
 :``<source name>``.min_range:
 
   ============== =============================