[mapserver-users] WCS Tile index question

[Carl Godkin]

Thanks again; I had messed up the gdaltindex paths so (as the debug log
told me), mapserver couldn't find the .hgt files.

I just fixed that and I'm thrilled to report I've got a WCS serving terrain
now.

Thanks so much!!
carl

On Wed, Oct 20, 2021 at 3:55 PM Rahkonen Jukka (MML) <
jukka.rahkonen at maanmittauslaitos.fi> wrote:

> Hi,
>
>
>
> I was just about to suggest to use DEBUG. GDAL does not use “wcs_native_format”,
> it is used for setting what will be written into DescribeCoverage.
>
>
>
> -Jukka Rahkonen-
>
>
>
> *Lähettäjä:* Carl Godkin <cgodkin at gmail.com>
> *Lähetetty:* torstai 21. lokakuuta 2021 1.50
> *Vastaanottaja:* Rahkonen Jukka (MML) <jukka.rahkonen at maanmittauslaitos.fi
> >
> *Aihe:* Re: [mapserver-users] WCS Tile index question
>
>
>
> Sorry, right after I sent that last reply to the list, I thought of
> turning up the DEBUG value in the mapfile to 5 and now I see it's not
> finding my .hgt files for some reason.
>
>
>
> I will dig into this; maybe mapserver + GDAL don't actually needs
> wcs_native_format.
>
>
>
> More later to the list if I sort this out.  I really appreciate the help
> you and Jeff and others on the list have given me!
>
>
>
> carl
>
>
>
> On Tue, Oct 19, 2021 at 5:37 PM Rahkonen Jukka (MML) <
> jukka.rahkonen at maanmittauslaitos.fi> wrote:
>
> Hi,
>
>
>
> Here is more accurate documentation but only in the text
> https://www.mapserver.org/ogc/wcs_server.html
>
>
>
> “The convention is that once (wcs|ows)_extent and one of (wcs|ows)_size
> and (wcs|ows)_resolution is set in the layer metadata, all the coverage
> specific metadata will be retrieved from there. Otherwise the source image
> is queried via GDAL, if possible.”
>
>
>
> It seems that only wcs_extent is documented in the list of metadata
> elements but this is what they do:
>
>    - wcs_extent defines the bounding box or your coverage -> that will go
>    into DescribeCoverage
>    - wcs_size is the size of the coverage as pixels -> pixel size can be
>    computed by extent and size
>    - wcs_resolution tells the pixel size explicitly -> size of the
>    coverage in pixels can be computed
>
>
>
> We have in the LAYER-METADATA:
>
> "wcs_resolution" "0.5 0.5"
>
> "wcs_extent"          "19970 6597278 749676 7785300"
>
>
>
> That should be enough and Describe Coverage will have correct limits,
> origin, and offset vectors in RectifiedGrid.
>
>
>
> -Jukka Rahkonen-
>
>
>
>
>
> *Lähettäjä:* MapServer-users <mapserver-users-bounces at lists.osgeo.org> *Puolesta
> *Carl Godkin
> *Lähetetty:* keskiviikko 20. lokakuuta 2021 1.17
> *Vastaanottaja:* mapserver-users at lists.osgeo.org
> *Aihe:* [mapserver-users] WCS Tile index question
>
>
>
> Hi again,
>
>
>
> I am working with Mapserver trying to set up a WCS layer based on a large
> collection of SRTM .hgt files.
>
>
>
> Since I have many input files instead of a single file, I want to use a
> tile index.  I know how to make and use a tile index for WMS, but there's a
> twist for WCS that I don't understand.
>
>
>
> According to this section of the docs:
>
>
>  https://mapserver.org/optimization/tileindex.html?highlight=wcs_resolution#note-for-wcs-layers
>
> <https://mapserver.org/optimization/tileindex.html?highlight=wcs_resolution#note-for-wcs-layers>
>
>
>
> I need to set “wcs_extent”, “wcs_size”, and “wcs_resolution” but I don't
> see where they are defined or documented.
>
>
>
> Can you point me to documentation?  The WCS Use Cases page gives some
> hints so I think I understand wcs_extent (though it's "ows_extent" in some
> examples there so I guess these are interchangeable?)
>
>
>
> How are the others defined?
>
>
>
> Thank you for your help,
>
> carl
>
>
>
>
>
>
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