Re: [mapserver-users] Point query from Mapserver raster

[Scott]

If you're using postgres/postgis it's easy using the raster version of 
st_intersection. It returns lat/lon/value or more precisely 
geometry/value. See more here:


https://postgis.net/docs/RT_ST_Intersection.html

Then it's just WFS.


On 10/29/21 4:09 PM, Carl Godkin wrote:

Hi,
Now that I have my WMS and WCS servers working well (thanks, list!!), I 
have one more thing I would like to figure out how to do.


I want to do point queries on [Lat,Lon] points for their elevation from 
the terrain layer I have.


I have done some searching and come across various ideas such as Raster 
Query (https://mapserver.org/input/raster.html#raster-query 
) and a query 
template  
(https://gis.stackexchange.com/questions/167239/mapserver-raster-picking-elevation-data 
) 
but haven't found enough information for either to implement it.


I came up with a solution that works fine, but might be considered as 
going "All Around the Barn"   What works is to add an ASCII output 
format to my map file that serves terrain like this:


OUTPUTFORMAT
NAME XYZ
DRIVER "GDAL/XYZ"
MIMETYPE "text/plain"
IMAGEMODE FLOAT32
EXTENSION "txt"
END

and then use GetCoverage on a small rectangle whose lower-left corner
is the point whose elevation I want:

http://localhost:8080/wcs?SERVICE=WCS&VERSION=2.0.1&REQUEST=GetCoverage&coverageid=SRTM_3_arc-second_grid&format=XYZ&subset=Lat(42.948,42.958)&subset=Lon(-122.086,-122.076) 



and then take the first line of the returned output file.

What would Mapserver best practice be for a problem like this?

Thanks very much,

carl









___
MapServer-users mailing list
MapServer-users@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/mapserver-users


___
MapServer-users mailing list
MapServer-users@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/mapserver-users

[mapserver-users] Point query from Mapserver raster

[Carl Godkin]

Hi,
Now that I have my WMS and WCS servers working well (thanks, list!!), I
have one more thing I would like to figure out how to do.

I want to do point queries on [Lat,Lon] points for their elevation from the
terrain layer I have.

I have done some searching and come across various ideas such as Raster
Query (https://mapserver.org/input/raster.html#raster-query) and a query
template  (
https://gis.stackexchange.com/questions/167239/mapserver-raster-picking-elevation-data)
but haven't found enough information for either to implement it.

I came up with a solution that works fine, but might be considered as going
"All Around the Barn"   What works is to add an ASCII output format to my
map file that serves terrain like this:

OUTPUTFORMAT
  NAME XYZ
  DRIVER "GDAL/XYZ"
  MIMETYPE "text/plain"
  IMAGEMODE FLOAT32
  EXTENSION "txt"
END

and then use GetCoverage on a small rectangle whose lower-left corner
is the point whose elevation I want:

http://localhost:8080/wcs?SERVICE=WCS&VERSION=2.0.1&REQUEST=GetCoverage&coverageid=SRTM_3_arc-second_grid&format=XYZ&subset=Lat(42.948,42.958)&subset=Lon(-122.086,-122.076)

and then take the first line of the returned output file.

What would Mapserver best practice be for a problem like this?

Thanks very much,

carl
___
MapServer-users mailing list
MapServer-users@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/mapserver-users