3

for someone skilled, I'm sure this will be piece of cake. I'm starting implementing WMTS into own application and even that I already use WMS for years, I have some troubles with understanding WMTS.

WMTS service: http://gis.lmi.is/arcgis/rest/services/kort_isn93/kort_isn93/MapServer (Island freely available maps) WMTS configuration: http://gis.lmi.is/arcgis/rest/services/kort_isn93/kort_isn93/MapServer/WMTS/1.0.0/WMTSCapabilities.xml

My confusions:

1. more confusion then problem

<ows:BoundingBox crs="urn:ogc:def:crs:EPSG::3057">
  <ows:LowerCorner>-22417.9302 166013.8265</ows:LowerCorner>
  <ows:UpperCorner>1048334.75710001 852747.7883</ows:UpperCorner>
</ows:BoundingBox>
<ows:WGS84BoundingBox crs="urn:ogc:def:crs:OGC:2:84">
  <ows:LowerCorner>-31.399192003034788 61.60136743056403</ows:LowerCorner>
  <ows:UpperCorner>-6.002491614773447 68.16183386054668</ows:UpperCorner>
</ows:WGS84BoundingBox>

Coordinates for lowerCorner converted from 3057 > 4326 do not match .. -28.8782279906;61.6383760341. Weird?

2. bigger problem

Every tileMatrix has defined TopLeftCorner

<TopLeftCorner>-3.45415E7 3.85236E7</TopLeftCorner>

But converted again to EPSG:4326 I get 30.6506275545;-69.2326947 . They look like just reversed, but no change in coordinates cause correct result.

For conversion I used nice web page: http://cs2cs.mygeodata.eu/ , same result anyway directly in own application.

Any hint, link to web page, whatever, is very welcome. Mainly second problem is very "problematic" as it do not allow to me compute correct bbox for map TileMatrix.

  • I converted the lower corner to 4326 using Postgis and got -28.878 61.638 which looks reasonable based on spatialreference.org/ref/epsg/3057 and where Iceland is in the world, somewhat west of London and distinctly north of the equator. As for your 2nd question, the bounds look totally wrong. Did you mean to use 3857 aka Web Mercator rather than 3057, which is just Iceland? – John Powell Jan 17 '16 at 16:33
  • The bounding box of data does not need to match the extents of the gridset as you can read from the WMTS standard. The TopLeftCorner of gridset of this service does not convert nicely into EPSG:4326 but it may be just because the top left corner is outside the really usable area for EPSG:3057. It may still work as WMTS - have you tried that service with QGIS? – user30184 Jan 17 '16 at 19:13
  • I have same result as you John as I wrote in the end of first part. Sorry, my question was not correct - I just expected, that bounds in 3057 will match to WGS84, but as you may see, they don't. And @user30184 , yes I tried and it display nothing, just empty map. But because button "Arcgis.com Map" in first mentioned page display map correctly, I expect it works. I absolutely understand and agree with what you wrote. Problem for me is that conversion end with 30.6506275545;-69.2326947 , but I expect values close to -30... and +69.., so here is where I really appreciate your help. – Menion Asamm Jan 17 '16 at 20:28

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