[GIS] MapProxy with WMTS source and reprojection

coordinate systemmapproxywmts

I am trying to consume Lantmateriet's WMTS source with EPSG:3006 and convert that to iOS TileOverlay compatible (GoogleMaps compatible) tile server. I cannot get it working. Can someone check this out and say what I am doing wrong.

mapproxy.yaml:

services:
  tms:
    use_grid_names: false
    origin: 'nw'
layers:
  - name: sweden
    title: sweden
    sources: [cache_sweden]
    tile_sources: [cache_sweden]

caches:
  cache_sweden:
    sources: [cache_sweden_original]
    grids: [GLOBAL_MERCATOR]
    meta_size: [4, 4]
    cache:
      type: mbtiles
  cache_sweden_original:
    sources: [source_sweden]
    grids: [grid_sweden]
    disable_storage: true
sources:
  source_sweden:
    type: tile
    grid: grid_sweden   
    url: 'https://api.lantmateriet.se/open/topowebb-ccby/v1/wmts/token/mytoken/?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=topowebb&STYLE=default&TILEMATRIXSET=3006&TILEMATRIX=%(z)s&TILEROW=%(y)s&TILECOL=%(x)s&FORMAT=image/png'
grids:
  grid_sweden:
    srs: 'EPSG:3006'
    bbox: [-1200000.000000, 4305696.000000, 2994304.000000, 8500000.000000]
    origin: nw

This is what it looks now:

Capabilities of the WMTS source I am trying to use can be seen:
GetCapabilities.xml

Best Answer

The problem was with the res-parameter. I had to calculate the scales based on the GetCapabilities. Here is a good guide how to do it properly https://lists.osgeo.org/pipermail/mapproxy/2013-August/001674.html

The final grid definition was

grid_sweden_3006:
   srs: 'EPSG:3006'
   bbox: [-1200000, 4305696, 2994304, 8500000]
   origin: nw
   res: [
     #  res            level     scale @90.7 DPI
     4096.0000000000, #  0    14628571.42857143
     2048.0000000000, #  1     7314285.71428571
     1024.0000000000, #  2     3657142.85714286
      512.0000000000, #  3     1828571.42857143
      256.0000000000, #  4      914285.71428571
      128.0000000000, #  5      457142.85714286
       64.0000000000, #  6      228571.42857143
       32.0000000000, #  7      114285.71428571
       16.0000000000, #  8       57142.85714286
        8.0000000000, #  9       28571.42857143
   ]                  # the end

Related Solutions

[GIS] proper succession of coordinates while specifying TopLeftCorner in TileMatrix in WMTS

It seems that all WMTS service that were suspicious in my question, were right; I was wrong.

World of CRS definitions is not so simple.

Actual axis order to be used while constructing TopLeftCorner, results from CRS definition.

It has been explained e.g. at http://www.geotoolkit.org/modules/referencing/faq.html#axisOrder.

For CRS like EPSG:3857, EPSG:32633, axis order is "natural", i.e. horizontal one first, then vertical one.

For CRS like geodetic EPSG:4326, and projected EPSG:2180, EPSG:3006, axis order is "reversed", i.e. vertical one first, then horizontal one.

Despite this fact, coordinates in BoundingBox and WGS84BoundingBox are always listed in "natural" succession.

Actual order of axes can be detected by examining appropriate part of WKT representation of given CRS containing AXIS tags, e.g.:

EPSG:3857: AXIS["X",EAST],AXIS["Y",NORTH]
EPSG:32633: AXIS["Easting",EAST],AXIS["Northing",NORTH]

EAST first, then NORTH - no swapping required

EPSG:2180: AXIS["x",NORTH],AXIS["y",EAST]
EPSG:3006: AXIS["x",NORTH],AXIS["y",EAST]

NORTH first, then EAST - swapping is required

For geodetic CRS, swapping from lat, lon order to lon (horizontal), lat (vertical) is always required.

Or maybe there are other geodetic CRS that use lon, lat order? There are no AXIS tags in WKT for EPSG:4326.

[GIS] Using Leaflet and Web Map Tile Service (WMTS)

I think the issue you had was because Lantmäteriet is using SWEREF 99/EPSG:3006 projection and Leaflet is using EPSG:3857. My solution was to use proj4leaflet to transform between those projections, like this:

import L from 'leaflet';
import { CRS } from 'proj4leaflet';

const apiKey = process.env.LANTMATERIET_TOKEN;

// This is the important task, where we set the map projection to EPSG:3006
const crs = new L.Proj.CRS('EPSG:3006',
  '+proj=utm +zone=33 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs',
  {
    resolutions: [
      4096, 2048, 1024, 512, 256, 128, 64, 32, 16, 8
    ],
    origin: [-1200000.000000, 8500000.000000 ],
    bounds:  L.bounds( [-1200000.000000, 8500000.000000], [4305696.000000, 2994304.000000])
  });

const map = new L.Map('map', {
  crs: crs,
  continuousWorld: true,
});

new L.TileLayer(`https://api.lantmateriet.se/open/topowebb-ccby/v1/wmts/token/${apiKey}/?service=wmts&request=GetTile&version=1.0.0&layer=topowebb&style=default&tilematrixset=3006&tilematrix={z}&tilerow={y}&tilecol={x}&format=image%2Fpng`, {
  maxZoom: 9,
  minZoom: 0,
  continuousWorld: true,
  attribution: '&copy; <a href="https://www.lantmateriet.se/en/">Lantmäteriet</a> Topografisk Webbkarta Visning, CCB',
}).addTo(map);

You can see my full example at https://github.com/kontrollanten/lantmateriet-leaflet

Best Answer

Related Solutions

[GIS] proper succession of coordinates while specifying TopLeftCorner in TileMatrix in WMTS

[GIS] Using Leaflet and Web Map Tile Service (WMTS)

Related Question