I have a simple SL map that is using the Web Mercator SR. The base map is coming from ESRI and operational locally hosted dynamic layer showing parcels. The parcels (and service) have been projected into Web Mercator to match ESRI, Google, Bing, etc. When measuring lengths and areas using the MeasureAction, incorrect lengths and areas are reported.
The reported values are the same that I get when using the Measure tool in ArcMap with the same parcel service and source feature classes. In ArcMap there is the option to measure using the Geodesic, which returns the correct lengths, but not areas. And there is no property on the MeasureAction to distinguish between a Planar or Geodesic measurement.
To get an accurate measuring tool in SL, the method I am now working on is to have two Maps in the SL app; a MainMap with all of the operational and base layers, and a MeasureMap which has no layers, uses a UTM SR, is transparent and is initially collapsed. When the user uses the measure tool on the map, via the MaeasureAction, the MeasureMap will become Visible (although the user still can't see it because it is transparent and has no layers) an zoom to the extent of the MainMap. The MeasureAction Map property is set to use the MeasureMap, thus hopefully measuring lengths and areas with UTM instead of WebMercator.
Does anyone know of an easier way to get accurate length/area measurements and also have the MebMercator SR.
Thanks much for any ideas.
