Spherical/Web Mercator (EPSG:3857) is the projected coordinate system commonly used for web mapping and in services such as Google Maps and OpenStreetMap (OSM). It supports map tile services that have worldwide coverage, or that need to interact with third party tile services without needing you to reproject or scale.
To support interoperability of LDS tile services with other mapping services such as OSM and Google Maps, Toitū Te Whenua has adopted the well-known tile scale set for this coordinate reference system.
This tile set has global coverage, including New Zealand and its offshore islands.
Specification
This specification is based on Annex E of the Open Geospatial Consortium’s Web Map Tile Service Standard.
| Zoom Level | Scale, EPSG:3857 (GoogleMapsCompatible) |
|---|---|
| 0 | 559082264.02871776 |
| 1 | 279541132.01435888 |
| 2 | 139770566.00717941 |
| 3 | 69885283.00358972 |
| 4 | 34942641.50179486 |
| 5 | 17471320.75089743 |
| 6 | 8735660.3754487149 |
| 7 | 4367830.1877243565 |
| 8 | 2183915.0938621792 |
| 9 | 1091957.5469310889 |
| 10 | 545978.77346554468 |
| 11 | 272989.38673277228 |
| 12 | 136494.6933663862 |
| 13 | 68247.346683193085 |
| 14 | 34123.673341596543 |
| 15 | 17061.836670798271 |
| 16 | 8530.9183353991357 |
| 17 | 4265.4591676995678 |
| 18 | 2132.7295838497839 |
| 19 | 1066.364791924892 |
| 20 | 533.18239596244598 |
| 21 | 266.59119798122299 |
- WGS 84 / Web Mercator (EPSG:3857) is sometimes referred to as Google Web Mercator with a reference code of EPSG:900913.
- The map tile you see in the LDS website map preview window is defined using the WGS 84/ Web Mercator tile scale set.
- LDS supports zoom levels 19 to 21, which are not defined as part of the OGC specification. This is to allow zooming in to smaller scales.