Filtering out dust/fog/smoke using DUAL RETURNS

[Pallav1299]

Hi @Samahu @kairenw

1. We're using Ouster OS0-32 Rev-06 Lidar. We're using the latest ouster_ros driver in LEGACY mode. We recently realized that dust is being detected in the pointcloud. I know that we can get two pointcloud rostopics (points1, points2) by setting to DUAL RETURN mode in ROS driver, and leverage the second pointcloud topic to get pointcloud data without dust particles detection. But, how should I use the second pointcloud?
2. Shouldn't the pointcloud comprise of points with second return whenever there are dual returns? Please provide reference documentation for the same.
3. Could you please also tell, which resolutions support DUAL RETURN mode?

Platform:

• Ouster Sensor? OS-0
• Ouster Firmware Version? v2.5.2
• ROS version/distro? melodic
• Operating System? Linux
• Machine Architecture? arm64
• git commit hash (if not the latest).