Hi all,
I just received a LiDAR dataset consisting in five different folders. I am reporting the label of those folder in case there is a standard nomenclature: c_1, c_2, c_3 ,c_4 and c_5.
All the datasets cover the same area. Provided that c_1 represents the DTM (floating) and c_2 represents the DSM (floating), the issue I have is identifying the remaining three layers, and specifically:
- c_3 has a 'unsigned integer' pixel type and a classification range from 0 to 255, maybe they are co-surface point groups?
- c_4 has a 'unsigned integer' pixel type with just 4 groups under the value 'Area'
-c_5 is almost identical to c_1 (the DTM) with slightly different values.
Any help on the meaning of all these layers??
Thanks anyone in advance.
Alessandro
Hi,
you can find description for LiDAR file format below the link.
https://www.asprs.org/committee-general/laser-las-file-format-exchange-activities.html
best
Hello-
My recommendation would be to contact the vendor for an explanation. There are no standard folder naming conventions for LiDAR data. The standards referenced by the ASPRS website are in regards to the las files, not folder names. I also wouldn't assume that c1 and c2 are the DTM and DSM only because there's no standard for folder naming. Of course all of this could be resolved if there was metadata written, but I'm assuming this doesn't exist either.
Good luck
-al
I agree with Al, the best thing to do is to get metadata from the data vendor or agency/person responsible for organizing the folders. If that's not possible, you'll be left to explore it yourself. Determining which is the bare earth (DTM/DEM; nomenclature is different) vs. highest hit (DSM) shouldn't be too difficult. I would guess that c_3 is either a shaded relief or intensity grid (should be easy to check); c_4 might be a grid of classification codes, date codes, or some other metadata; c_5 may be an unclassified version of c_1, or be provided in a different projection/coordinate system. I think the first three folders will likely be the easiest to determine, while the others will likely require more information.
Dear Alessandro,
If the c_3 is a raster format, it can be the DTM or DSM as an image.
However, if the c_3 is also "a point cloud", it could be representing a normalization of the pulse intensity received from the targets.
Considering the c_4 folder, I would suggest you to investigate if it is a classification of the mapped area (such as 1-ground; 2-vegetation; 3-buildings; 4-unclassified).
Alan is right, the dataset provider must give you the metadata.
Good luck.
HCO
I think the five folders related to the five bands (the reflectance information from the LiDAR data ), it depend on the features and the pulse of laser beam.
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