get user defined point information from XY input

[Toon Petermans]

Hello,

 

In the past I used the tool lascontrol to get the Z value of an input XY position. However if you want to have more information like classification, point source id, RGB,…  lascontrol don’t provide this information. It is only intended for z information.

Another possibility is to use lasclip , but this works only with polygons and  not with a point shape or with a “a nearest point” option. However, there is a possibility (also with las2txt) to get information with the extra option -inside_circle center_x center_y radius, but 1) it does not guarantee that you will obtain information for a certain radius and 2) I’m only interested for the closest laz point and 3) I want to get information for many xy inputs in one time.

So, question is, if there is another possibility in lastools to get easily point information from one or more given input XY positions.

In fact what I really would like is the capability that lascontrol could output with an option  –oparse  (as in las2txt) where user can add additional las attributes that will be stored in the output file.

 

Best regards,

 

Toon

 

 

Met vriendelijke groeten,

 

Toon Petermans

R&D Developer

Geodiensten - dienst IT

 

INFORMATIE VLAANDEREN

T 09 2761617

Toon.pe...@agiv.be

Koningin Maria Hendrikaplein 70, 9000 Gent

www.vlaanderen.be | www.agiv.be

 

Stel je vraag aan de overheid!

Bel gratis 1700 of surf naar www.vlaanderen.be

 

//////////////////////////////////////////////////////////////////////////////////

 

---

Informatie Vlaanderen e-mail disclaimer: http://www.vlaanderen.be/informatievlaanderen

[Martin Isenburg]

Hello Toon,

sounds like you really want a new tool such as "lasprobe" that gives you the closest point(s) in respect to a certain x/y or x/y/z position given a certain search radius. I had more than once considered such a tool. What "lascontrol" gives you is a height that is interpolated from the triangle that covered the x / y coordinates of the x / y coordinates of a given (ground control) point.

Can you describe what you would like the new "lasprobe" tool to do in a bit more detail? I cannot promise how soon I can deliver this tool but it had already been on my TODO list ...

Regards from Istanbul,

Martin @rapidlasso

--
Download LAStools at
http://lastools.org
http://rapidlasso.com
Be social with LAStools at
http://facebook.com/LAStools
http://twitter.com/LAStools
http://linkedin.com/groups/LAStools-4408378
Manage your settings at
http://groups.google.com/group/lastools/subscribe

[Toon Petermans]

Hi Martin,

 

That is already great that your todolist is my wishlist (-:

 

I’m currently working on a tool to extract profiles over rivers from different source of merged LiDAR data (bathymetry and airborne LiDAR) for plotting purposes and then automatically extract river embankments. lascontrol is an ideal tool for this because you can input the xy positions of the profile, and the tool gives back the interpolated positions. However, I would like that the resulting points also get the “closest” classification, so I can give each point a classification colour, so I can distinguish bathymetry and airborne ground points.

 

The tool lasprobe would be very interesting to input xy coordinate(s) and give back all desired information from the nearest point. It could be an advanced option that Z is an interpolated value instead of the nearest value. I would also love that it will read many points at once from a txt or csv  file like lascontrol already does and then works with the ‘oparse’ option where you can specify the desired LAS Point data records and output to txt or csv format or maybe shp.

Another possibility is that lasclip could work with point shapes or polylines (of a profile) and give back the nearest points.

 

Thanks for spending time for this!

 

Cheers,

Toon