[pdal] Filtering atmospheric noise

[Andreas Yankopolus]

They’re mostly marked at 1 (unclassified) but I’ve seen a few that are 11 (road surface)!

> On Mar 9, 2022, at 17:05, Kirk Waters - NOAA Federal <kirk.waters at noaa.gov> wrote:
> 
> Is there any chance the points are marked as withheld? I've seen quite a bit of data where bad points are marked as withheld but not marked as noise.
> 
> Kirk Waters, PhD 
> NOAA Office for Coastal Management
> Applied Sciences Program      
> ‪Phone: 843-284-6962‬ (New as of 2022) 
> coast.noaa.gov/digitalcoast <http://coast.noaa.gov/digitalcoast>
> 
> 
> 
> 
> On Wed, Mar 9, 2022 at 4:45 PM Andreas Yankopolus <andreas at yank.to <mailto:andreas at yank.to>> wrote:
> All—
> 
> I’m using USGS 3DEP point-clouds to generate surface-height rasters around Longmont, CO. The point-cloud files have spurious returns over many of the lakes/reservoirs in the area that are tagged other than 7 or 18. They’re streaks about 0.3 m long located 200+ m above the lake. In most cases the streak has 3–8 points, but I’ve found one with 34 points.
> 
> The outlier filter with statistical or radius methods doesn’t remove these longer streaks. Any recommendations on removing dense groups of points well separated from the main mass?
> 
> I’m having success with:
> 
> {
> "type": "filters.outlier",
> "method": "radius",
> "radius": 16.0,
> "min_k": 64
> }
> 
> This seems to do the trick of removing isolated groups while leaving the main body of points alone, but I’m thinking these some other dimension that could be calculated and added to points then used to remove outlier groups later.
> 
> Cheers,
> 
> Andreas
> _______________________________________________
> pdal mailing list
> pdal at lists.osgeo.org <mailto:pdal at lists.osgeo.org>
> https://lists.osgeo.org/mailman/listinfo/pdal <https://lists.osgeo.org/mailman/listinfo/pdal>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/pdal/attachments/20220309/fdba9e08/attachment.html>