[mapserver-users] [External] Re: serving sparse DTED with WCS

[Burkhardt, Glenn B UTAS]

This works perfectly for me.  Missing 1x1 deg tiles from a bounding box are correctly reported as missing, and if there is missing data within a tile, it also is reported as missing.  Thanks!

Suggestion for improvement:  when the data file supplied to Mapserver is Geotiff, and a " NoData Value" is supplied, automatically use it as a null value for the layer.

-----Original Message-----
From: Even Rouault [mailto:even.rouault at spatialys.com] 
Sent: Thursday, April 5, 2018 10:02
To: mapserver-users at lists.osgeo.org
Cc: Burkhardt, Glenn B UTAS <Glenn.Burkhardt at utas.utc.com>
Subject: [External] Re: [mapserver-users] serving sparse DTED with WCS

On mercredi 4 avril 2018 19:51:56 CEST Burkhardt, Glenn B        UTAS wrote:
> DTED data is notoriously sparse.  If one combines all the files in a 
> DTED dataset into a single Geotiff file using something like " 
> gdalwarp -co TILED=YES */*.dt2 dted2.tif"
> 
> But GDAL will build a bounding box that's square with the world, and 
> there might not be data for every 1x1 deg section of the bounding box.
> 
> When this happens, Mapserver fills in the missing data with zeros. 
> Additionally, there might be data missing from within a 1x1 deg DTED 
> file, and it is marked with a  NODATA flag of -32767.
> 
> Is there some way for Mapserver to communicate to a client where data 
> is missing?  I can't find anything in the coverage information 
> provided to a WCS 1.0.0 client.

Glenn,

You can define in the LAYER.METADATA section things like for WCS 1.0 and WCS
1.1

"wcs_rangeset_nullvalue" "-32767"

Actually I see this wasn't documented. I've just added it in http://mapserver.org/ogc/wcs_server.html

For WCS 2, use "wcs_nilvalues"

Even

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