[Qgis-user] LiDAR Data in QGIS

Mon Dec 11 05:42:51 PST 2017

I'm dealing with a different issue here in Tennessee - We have the original 
files except they are locked in zlas (ESRI Proprietary Format) BUT - I can get 
it out of zlas so I can have fun with the LAS files. 

Good news is - LAS was a thing in 2003 (https://www.asprs.org/committee-general/laser-las-file-format-exchange-activities.html) so you might be able to 
get those OR at least a CSV file. 

You might have to go back to the vendor. They probably have them but might 
take some work to pry the files out of them. 2003 might be a life time ago for 
many. 

Good luck though! and take a look at GRASS and PDAL. I feed the LIDAR data 
into GRASS and pull the returns out or reprocess it. I'm not that great at 
doing it but learning. 

Randy

-- 
Randal Hale
North River Geographic Systems. Inc 
rjhale at northrivergeographic.com
(423) 653-3611 

On Monday, December 11, 2017 8:33:49 AM EST Tyler Veinot wrote:
> Randy;
> I figured as much; the DEM/DSM/DTM's were delivered to us from the province
> in that Esri Binary Grid Format, so we do not have the original LiDAR
> LAS/LAZ files on hand. It would also seem that we didn't keep the LAS/LAZ
> files from the original 2003 LiDAR survey of the city either.
> I sent an email to the province to see if they have and are willing to
> share the original data but got no reply as of yet.
> Tyler
> 
> On Mon, Dec 11, 2017 at 9:10 AM, Randal Hale <
> 
> rjhale at northrivergeographic.com> wrote:
> > I've only been watching this thread when I remember - so My apologies.
> > 
> > If I go back to the original thread - if these are in ADF I believe that's
> > ESRI's GRID Format. Which means they are what they are and you can't do
> > much
> > with them. They have only the last return (or if I remember correctly
> > returns
> > classed 2,8, etc).
> > 
> > If you have zlas, las, or laz - I would suggest GRASS for processing:
> > https://
> > grasswiki.osgeo.org/wiki/LIDAR
> > 
> > If you don't have any of the las/laz formats - you might want to do some
> > research and see if they were delivered with the LIDAR dataset you have or
> > if
> > they weren't request them. They may be sitting somewhere on a
> > shelf/forgotten
> > folder on a server. You can do a lot more with the original LIDAR files
> > like
> > pull tree heights or possibly rebuild the surface (be it dsm/dtm/dem etc).
> > 
> > Randy
> > 
> > --
> > Randal Hale
> > North River Geographic Systems. Inc
> > rjhale at northrivergeographic.com
> > (423) 653-3611
> > 
> > On Monday, December 11, 2017 7:27:00 AM EST Tyler Veinot wrote:
> > > All;
> > > But if I convert the DEM or DSM to geotiff I still wont get back the hit
> > > order or the classification values will I? I will just have the data I
> > 
> > have
> > 
> > > as processed in a different format. What I really need is the original
> > > LiDAR datasets if I am understanding this correctly.
> > > As for DTM, DSM, and DEM, The province my municipality is in has decided
> > > that; DTM is a surface model which includes surface features + ground
> > 
> > hits
> > 
> > > + breaklines. A DEM is ground hits, and a DSM as is the surface +
> > 
> > features
> > 
> > > without added breaklines. I have found definitions online to support
> > > both
> > > view points on the matter; just an FYI my text books agree with you on
> > 
> > the
> > 
> > > matter. I blame AutoCAD/CADD users for the discrepancies because, in my
> > > experience according to the EIT's and other CADD users, a DTM is all of
> > 
> > the
> > 
> > > above and a DSM and DEM doesn't exist lol.
> > > Thanks for the help on this;
> > > Tyler
> > > 
> > > 
> > > On Mon, Dec 11, 2017 at 6:31 AM, Richard McDonnell <
> > 
> > richard.mcdonnell at opw.ie
> > 
> > > > wrote:
> > > > 
> > > > Morning Tyler.
> > > > Nick is quite right. The files you have (ADF) are either DTM's or
> > 
> > DSM's.
> > 
> > > > They are processed datasets.
> > > > To fix the GRASS, SAGA issue, you can use GDAL to convert them to
> > 
> > GeoTiff,
> > 
> > > > using the gdal_translate, which can be found in the Processing toolbox
> > 
> > and
> > 
> > > > will do it for a few using batch (Note Point one below).
> > > > The other option would be to use the Script below to convert ADF to
> > > > GeoTiff.
> > > > 
> > > > *@echo off
> > > > SET startpath=%1
> > > > FOR /R %startpath% %%f IN (w001001.adf) do (call :translate "%%f")
> > > > pause
> > > > GOTO :eof
> > > > 
> > > > :translate
> > > > :
> > > >   SET var=%~dp1
> > > >   ECHO Translating %var%hdr.adf to %var:~0,-1%.tif
> > > >   gdal_translate -co "NUM_THREADS=ALL_CPUS" -co "TILED=YES" -co
> > > >   "COMPRESS=LZW" %var%hdr.adf %var:~0,-1%.tif*>
> > > > 
> > > > The tool/script works in the following way.
> > > > 
> > > >    1. *ADF Image names are the containing folder name*
> > > >    2. You must run this Batch in the Root folder for your ADFs (one
> > 
> > level
> > 
> > > >    up from the ADF files)
> > > >    3. Paste/save the batch in the root folder
> > > >    4. Open an instance of OSGeo4W Shell or its Linux counterpart
> > 
> > navigate
> > 
> > > >    to the root folder and run the script by typing *adf2tiff.bat*
> > > >    5. It will start to write the Tiff files into the root folder.
> > > > 
> > > > Hope this helps, or goes some way to helping.
> > > > Regards
> > > > 
> > > > Richard.
> > > > --
> > > > *Richard McDonnell*
> > > > *GIS Specialist PgD GIS AssocSCSI*
> > > > 
> > > > <http://www.opw.ie/>
> > > > 
> > > > 
> > > > Email Disclaimer: http://www.opw.ie/en/disclaimer/
> > > > 
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