smoothing lidar data

LPlateAndy

Hi,

Couldn't find anything that quite fitted my requirement in the documentation or forums...

I'm wondering if there is a way to remove some of the "noise" from LiDAR data within Global Mapper.

We have some .las files which we're turning into a DSM. The default settings give a 5cm interval grid DSM but the noise makes for a fairly unviewable model (the shading tends to go overboard).

I've run again at lower resolutions (25cm is probably optimum for retaining the data quality) but there is still some "noise".

I wondered if there is a way to specify a tolerance when generating a model so that smooth faces are created for open ground and building roofs - i can do something similar in my GIS but it's not as efficient in general as Global Mapper.

An example of what i'm thinking of can be found on the ESRI site (we don't actually use ESRI but it seemed a good example) here:

http://blogs.esri.com/Dev/blogs/geoprocessing/archive/2009/09/02/Lidar-Solutions-In-ArcGIS_5F00_part7_3A00_-Minimizing-noise-from-lidar-for-contouring-and-slope-analysis.aspx

Any help would be greatly appreciated.

Thanks

Andy

global_mapper

Andy,

Thanks for the link to the great article. That gives me some ideas for new features.

Currently the thinning methods discussed in the article are not available in Global Mapper. When you load the Lidar data in Global Mapper there is a 'Preview Mode' option that will just load every 10th point, which may help depending on how the point samples are organized.

Other than that, you can try gridding the data and specifying a larger grid sample spacing. This may smooth things out a bit for you.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

LPlateAndy

Hi Mike,

Thanks for the response, resampling does smooth but i'd like to keep the detail where it matters and lose the "noise" on the flat surfaces.

Pleased the article was of use and i look forward to seeing what comes out of it!

Cheers

Andy

LPlateAndy

Hi Mike,

Just wondering whether you have ever had time to consider this again - you seemed to agree it was a good piece of functionality at the time.

We're interested as CAD users often can't cope with the non optimised data due to the sheer volume of data...

Thanks

Andy

BTW, V12 is great - congratulations as always on the product

global_mapper

Andy,

We haven't had time to look at this again yet, but it's still on the todo list.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

jlindeman

Any chance this issue has been revisited?