I'm trying to create an introductory GIS course that will involve an ideally simple web mapping component. I was underwhelmed that ArcGIS online doesn't support rasters, and surprised that MangoMap and GeoCommons don't appear to either at the moment. Is anyone familiar with a webmapping site with a fairly simple UI that allows the uploading of raster data in addition to vector?
You can publish rasters as Image Services using ArcGIS.
Note the key concepts for image services. Most importantly:
Here are some examples from ArcGIS Online showing image services in action.
Arcgis-online supports raster when they rendered to tiles: You will need arcgis-desktop 10.1 for this. See the help file how to do this: http://resources.arcgis.com/en/help/main/10.1/#/Hosted_tiled_map_services/01w10000003r000000/
Mapbox also offers a service that can host raster-tileservers. they offer a free tool called tilemill to generate these tiles. These tiles can be use in arcgis-online: http://mapbox.com/blog/arcgis-online-export – warrieka