Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

What are LaserScan intensities?

2d_laser_scanner

asked 2015-07-19 21:30:51 -0500

nodge
65 ●5 ●7 ●11

updated 2015-07-20 03:59:07 -0500

mgruhler

12390 ●32 ●193 ●173 https://github.com/mgruhler

Hi, the LaserScan ROS message is

Header header
float32 angle_min        # start angle of the scan [rad] 
float32 angle_max        # end angle of the scan [rad]
float32 angle_increment  # angular distance between measurements [rad]
float32 time_increment   # time between measurements [seconds] 
float32 scan_time        # time between scans [seconds]
float32 range_min        # minimum range value [m] 
float32 range_max        # maximum range value [m]
float32[] ranges         # range data [m] (Note: values < range_min or > range_max should be discarded)
float32[] intensities    # intensity data [device-specific units]

What are the intensities?

Thanks!

John

edit retag flag offensive close merge delete

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2015-07-20 02:20:54 -0500

mgruhler

12390 ●32 ●193 ●173 https://github.com/mgruhler

The intensities field should contain the measured intensity (i.e. brightness) of the reflected laser beams. This is, however, device specific and thus you cannot really make any assumptions about the values. In general, the higher the value, the brighter the reflected laser beam.

You can use the intensities to make some assumptions about the properties of the scanned material. E.g. it is used to detect reflectors and reflector tape, as there the intensity of the reflected beam is, in general, higher than from other material.

E.g. the Hokyuo Laser scanner provides full intensities, whereas the Sick S300 only provides information about whether it detects a Reflector Tape (0 if none, not 0 if a reflector tape detected).

edit flag offensive delete link

add a comment

Question Tools

Stats

Asked: 2015-07-19 21:30:51 -0500

Seen: 5,009 times

Last updated: Jul 20 '15

What are LaserScan intensities? edit

1 Answer

Question Tools

Stats

Related questions

What are LaserScan intensities?