Limit the range scan on the TurtleBot3

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Hello, I am a beginner in ROS and I am doing a project with the Burger version of Turtlebot3. Turtlebot3’s LDS default is set to 360 but I want to modify to 24. I know how to make this in the gazebo simulation. You can modify sample of LDS at: turtlebot3/turtlebot3_description/urdf/turtlebot3_burger.gazebo.xacro.

<scan>   
    <horizontal>
      <samples>360</samples>            # The number of sample. Modify it to 24
      <resolution>1</resolution>
      <min_angle>0.0</min_angle>
      <max_angle>6.28319</max_angle>
    </horizontal>
</scan>

The doubt is that I don't know how do to the same in the real version.