[pdal] Merging buffered tiles

[Eric Robeck]

Andrew,

Sure, no problem. I sent you and Howard copies of the files in a separate
email. They are as follows:

1.  "clean_tile_18.las": the original file I created using PDAL to tile and
convert from LAZ 1.4 to LAS 1.2)
2.    "mcc_tile_18.las": the tile created by MCC-LIDAR after ground
classification
3.    "lasground_tile_18.laz": the tile created by LASTools lasground.exe
from the LAS file, but recompressed by lasground

I also think I identified the problem. I thought the input 'mcc' tiles were
in Missouri East State Plane coordinates, because I had projected some MCC
inputs before, so I told PDAL to convert them from EPSG 26915 (Missouri
East State Plane) to EPSG 32615 (UTM 15N):

      "inputs":"merge_tiles",
      "type":"filters.reprojection",
      "tag":"reproject_tiles",
      "in_srs":"EPSG:26915",
      "out_srs":"EPSG:32615"

Apparently PDAL was smarter than me, because it recognized the inherent
coordinate system and did NOT reproject the data. When I took out the
reprojection stage and ran the pipeline again, it finished without errors.
PDAL protected me from my own mistake, so maybe that was its way of
detecting the discrepancy.

I hope that helps.

Regards,
Eric

On Thu, May 3, 2018 at 2:54 PM Eric Robeck <erobeck at gmail.com> wrote:

> Sure, no problem. I've attached copies of my smallest tile here. They are
> as follows:
>
>    - "clean_tile_18.las": the original file I created using PDAL to tile
>    and convert from LAZ 1.4 to LAS 1.2)
>    - "mcc_tile_18.las": the tile created by MCC-LIDAR after ground
>    classification
>    - "lasground_tile_18.laz": the tile created by LASTools lasground.exe
>    from the LAS file, but recompressed by lasground
>
> I also think I identified the problem. I thought the input 'mcc' tiles
> were in Missouri East State Plane coordinates, because I had projected some
> MCC inputs before, so I told PDAL to convert them from EPSG 26915 (Missouri
> East State Plane) to EPSG 32615 (UTM 15N):
>
>       "inputs":"merge_tiles",
>       "type":"filters.reprojection",
>       "tag":"reproject_tiles",
>       "in_srs":"EPSG:26915",
>       "out_srs":"EPSG:32615"
>
> Apparently PDAL was smarter than me, because it recognized the inherent
> coordinate system and did NOT reproject the data. When I took out the
> reprojection stage and ran the pipeline again, it finished without errors.
> PDAL protected me from my own mistake, so maybe that was its way of
> detecting the discrepancy.
>
> I hope that helps.
>
> Regards,
> Eric
>
>
> On Thu, May 3, 2018 at 1:33 PM Andrew Bell <andrew.bell.ia at gmail.com>
> wrote:
>
>> Any chance you could share a couple of your input files?
>>
>> On Thu, May 3, 2018 at 2:26 PM, Andrew Bell <andrew.bell.ia at gmail.com>
>> wrote:
>>
>>> I'm confused by the error you get.  I'll run a test to see if I can
>>> figure out what might be going on.
>>>
>>> On Thu, May 3, 2018 at 12:02 PM, Howard Butler <howard at hobu.co> wrote:
>>>
>>>>
>>>> > On May 3, 2018, at 10:49 AM, Eric Robeck <erobeck at gmail.com> wrote:
>>>> >
>>>> > Howard,
>>>> >
>>>> > Yes, the parentheses crept in early while I tried to keep track of
>>>> the various parameter combinations used for my bare earth simulations, but
>>>> they caused headaches later on...
>>>> >
>>>> > As an update, I ran a slightly modified version of the same pipeline
>>>> (sample tile geometries, different source files) and got no errors. This
>>>> time the input files were in LAZ format and they were not reprojected.
>>>> Another factor could be that the first set were generated by the old(ish)
>>>> MCC-LIDAR application, and the latter by Isenburg's lasground.exe.
>>>>
>>>> That fact pattern would seem to confirm my hunch. This srs stuff is
>>>> definitely a topic we could improve.
>>>>
>>>> Howard
>>>> _______________________________________________
>>>> pdal mailing list
>>>> pdal at lists.osgeo.org
>>>> https://lists.osgeo.org/mailman/listinfo/pdal
>>>
>>>
>>>
>>>
>>> --
>>> Andrew Bell
>>> andrew.bell.ia at gmail.com
>>>
>>
>>
>>
>> --
>> Andrew Bell
>> andrew.bell.ia at gmail.com
>>
>
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