ArcGIS Online has migrated map tiling scheme of their map services to Google Maps and Microsoft Bing Maps well known tiling scheme. All ESRI Map resources can now overlayed and mashed-up with Google Map layers and Bing Map layers, because they use the same coordinate system, map DPI and tile size. Also cached levels of detail match with the Google/Microsoft “Industry Standard”.
For example their new topographic Map looks great and has a lot of details (at least in some parts of the US):
Some Map details from ArcGIS Online
Server URL: http://services.arcgisonline.com
Coordinate system: Web Mercator Auxiliary Sphere (WKID 102100)
Units of measure: Decimal degrees
| Global Extent: | Maximum Longitude: Approx. 180 | |
| Maximum Latitude: Approx. 85 | ||
| Minimum Longitude: Approx. -180 | ||
| Minimum Latitude: Approx. -85 | ||
Map DPI: 96
Tile Size of Map Cache: 256 pixels by 256 pixels
Levels of Detail: The number of cached levels of detail varies among map services. The scale levels are calculated, based upon the tile size (256 by 256) and the WGS 1984 Web Mercator coordinate system, such that when tiles are laid out starting at 180W and proceeding eastward, the final tile aligns perfectly (no overlap) with the first tile at the international date line.
These are the standard map scale and cell sizes:
| Layer level | Map scale | Cell size |
|---|---|---|
| L00 | 1:591,657,528 | 1 pixel = 1.40624 Decimal degrees (Meters at equator:156,543.033928) |
| L01 | 1:295,828,764 | 1 pixel = 0.70312 Decimal degrees (Meters at equator: 78,271.516964) |
| L02 | 1:147,914,382 | 1 pixel = 0.35156 Decimal Degrees (Meters at equator: 39,135.758482) |
| L03 | 1:73,957,191 | 1 pixel = 0.17578 Decimal Degrees (Meters at equator: 19,567.879241) |
| L04 | 1:36,978,595 | 1 pixel = 0.08789 Decimal Degrees (Meters at equator: 9,783.939620) |
| L05 | 1:18,489,298 | 1 pixel = 0.04395 Decimal Degrees (Meters at equator: 4,891.969810) |
| L06 | 1:9,244,649 | 1 pixel = 0.02197 Decimal Degrees (Meters at equator: 2,445.984905) |
| L07 | 1:4,622,324 | 1 pixel = 0.01099 Decimal Degrees (Meters at equator: 1,222.992453) |
| L08 | 1:2,311,162 | 1 pixel = 0.00549 Decimal Degrees (Meters at equator: 611.496226) |
| L09 | 1:1,155,581 | 1 pixel = 0.00275 Decimal Degrees (Meters at equator: 305.748113) |
| L10 | 1:577,791 | 1 pixel = 0.00137 Decimal Degrees (Meters at equator: 152.874057) |
| L11 | 1:288,895 | 1 pixel = 0.00069 Decimal Degrees (Meters at equator: 76.437028) |
| L12 | 1:144,448 | 1 pixel = 0.00034 Decimal Degrees (Meters at equator: 38.218514) |
| L13 | 1:72,224 | 1 pixel = 0.00017 Decimal Degrees (Meters at equator: 19.109257) |
| L14 | 1:36,112 | 1 pixel = 0.00009 Decimal Degrees (Meters at equator: 9.554629) |
| L15 | 1:18,056 | 1 pixel = 0.00004 Decimal Degrees (Meters at equator: 4.777314) |
| L16 | 1:9,028 | 1 pixel = 0.00002 Decimal Degrees (Meters at equator: 2.388657) |
| L17 | 1:4,514 | 1 pixel = 0.00001 Decimal Degrees (Meters at equator: 1.194329) |
| L18 | 1:2,257 | 1 pixel = 0.000005 Decimal Degrees (Meters at equator: 0.597164) |
| L19 | 1:1,128 | 0.000003 Decimal Degrees (Meters at equator: 0.298582) |
