[GRASS-dev] v.in.lidar: store return or class as category

[Newcomb, Doug]

As an example, the new North Carolina data set ( 2014 +) , the LiDAR
classes above 12 are being used for roads, (13) and bridges (14) .  I have
attached a two page flyer on the current NC project as a pdf.  If it
doesn't come through on the email list, let me know and I will email it
directly to you

Doug

On Tue, Sep 29, 2015 at 5:07 AM, Moritz Lennert <
mlennert at club.worldonline.be> wrote:

> On 28/09/15 22:02, Vaclav Petras wrote:
>
>>
>> On Sat, Sep 26, 2015 at 8:40 PM, Vaclav Petras <wenzeslaus at gmail.com
>> <mailto:wenzeslaus at gmail.com>> wrote:
>>
>>     Dear all,
>>
>>     in r66343 I've added the option to store return or class as
>>     category. This is much faster than storing them as attributes. Also,
>>     the further processing will be faster supposing that the subsequent
>>     workflow can use categories in the same way as attributes.
>>
>>     Return and class can be stored at the same time, each in its own
>>     layer, otherwise they would get mixed. There is no protection
>>     against specifying same layer for all, perhaps there should be.
>>
>>
>> Another thing which needs further consideration is category number when
>> class number is 0 (ASPRS: Created, never classified). Is 0 allowed for
>> category? Library documentation says no [1] but then it says yes for OGR
>> layers (and I suppose PostGIS as well). So how hard is the requirement?
>>
>
> I would plead for you to respect the library documentation, i.e. no 0 cats.
>
> If 0 should be changed in case of ASPRS/lidar class 0, then to what?
>>
>
> In the current specifications anything over 12 is "Reserved for ASPRS
> Definition". I don't know what this entails, but maybe we can use one of
> these values.
>
> On the other hand, 0 means "we've never tried to classify", while 1 means
> "we tried to classify, but were not able to". I'm not sure if the
> difference between these two is really important and so maybe we could just
> regroup all 0's and 1's into class 1 ?
>
> Moritz
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-- 
Doug Newcomb
USFWS
Raleigh, NC
919-856-4520 ext. 14 doug_newcomb at fws.gov
---------------------------------------------------------------------------------------------------------
The opinions I express are my own and are not representative of the
official policy of the U.S.Fish and Wildlife Service or Dept. of the
Interior.   Life is too short for undocumented, proprietary data formats.
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