Standards of open GIS, like openstreetmap, cloudmade?_问答_开发者

I am not familiar with the GIS (or map), but recently I have to do some work related to this field. I know some map providers: OpenStreetMap, CloudMadeMap, OpenCycleMap, OpenAerialMap开发者_如何学Go ...

My questions is: Do those map providers have the same standards? I mean the tile size, zoom levels, scales for each zoom level and so on.

Is there any standard for open GIS? If yes, where can I find them or some one could give me some references or links?

Yes, all the services you mention, along with many others in the open-source GIS mapping world, share the same defacto "z/x/y.png tile standard". The tile numbering, zoom levels, scales and so on are all the same across the these providers.

The "standard" isn't official, but the OCG are formalizing the details under the acronym "TMS", unfortunately in an incompatible way with what is in practice (different origin for the tile numbering. Gah!)

The OpenStreetMap wiki has the best description of the numbering scheme. You can display such tiles in OpenLayers using the XYZ or OSM layers. Note that the projection for all these layers is "Spherical Mercator", aka EPSG:900913 or EPSG:3857.

I run the OpenCycleMap servers, and was the Technical Lead for CloudMade when we chose this scheme. Both were chosen to be identical to OpenStreetMap, which in turn was based on the scheme Google were using at the time.

I am also very new to GIS programming, but it seems GIS is heavily standardized. From the storage layer (WKT, WKB), to the server layer (WMS, WFS, SLD..). Try lookinh those up on wikipedia (I think I can't post this many links with my reputation?).

We started developing using the following open source stack: PostGIS, GeoServer, OpenLayers and so far we are happy with our decision, everything fits together beautifully,

You might be interested in the Open Geospatial Consortium Web Map Service (WMS) standard. It is a standard protocol for serving georeferenced map images over the Internet.

Consumers of web map services can "mash up" lots of different layers from different providers to create their own applications.

There are no exact standards regarding tile sizes, zoom levels and such because these are highly customizable.

There are technical standards regarding file, db and web service formats. Some file formats of ESRI (i.e. Shapefiles) are de-facto standards, for better and for worse. Others are open standards from the OGC, but don't expect to see all of these open formats in commercial products (i.e. even the ubiquitous KML format is not 100% supported in ESRI products).

There are two relevant OGC standards with regard to map tiling. The Web Map Tiling Service (WMTS) currently in candidate standard form and a proposed extension to WMS to add a cached/tiled version.

So the short answer is "no", there's no official standard yet.

The three major vendors have standardized on a defacto standard for tiling scheme's. A description of the scheme can be found here, among other places.

From what I know of the map providers you listed, they each have their own scheme... though I don't know for sure. You will likely have to check each individual provider for their tiling scheme. You will also need to make sure that their usage agreements let you use the tiles directly (as opposed to using any API they might provide).

This doesn't really speak to standards, but I thought it worth pointing out that the first three you mentioned, OpenStreetMap, CloudMadeMap, and OpenCycleMap, are all related projects.

OpenStreetMap is the project to collect the open mapping data, OpenCycleMap is an implementation that uses that data to a create a map tailored to Cyclists, and Cloudmade is a for-profit company founded by a number of the people who founded the OpenStreetMap project, and they also use its data.

When I wanted to add OpenStreetMap data to my website, I ended up using a (for now, free) tile serving service offered by Cloudmade. This saved me having to worry about generating tiles or serving them myself. I've had a good experience with it.