How to know point's intensity value
SENSR does not offer each point's intensity value. But here's useful application to know about the point clouds - Rviz.
Type
sudo apt-get install ros-melodic-rvizto download RvizType
rvizto turn on the application

- Click add button to see the pointcloud
- Choose your topic name in
By topicmenu

- Change the Fixed frame. You can check Status in your topic
- You can change the various parameters to see points easier(blue box)

- Click the Select button(blue box) and drag the area of which you want to see the intensity value of the point cloud.