Web Mercator Completely Fails to Measure

06-11-2015 01:20 PM
Status: Open
New Contributor III
 We use the same in-house cadastral  feed  projected into web mercator auxillary sphere to populate our intranet map and for desktop background to aid in location and estimation. We understand that measures will be a little off, maybe  up to 10%. However, it is 200% wrong and quite misleading in ArcMap desktop, which is not the case in our intranet ArcGIS for Server map. A township measures approximately 36 sq.mi in the web-based browser map but in desktop that same township  measures approximately 72 sq.mi. No one's buiding a fence but still the error is astounding!! Let's get it fixed. Below is part of the response I received from ESRI.

From ESRI Tech support

Hello Conrad,

As we discussed I have logged BUG-000088279 [Geodesic Areas cannot be calculated in the Measure Tool in ArcMap, if the Data Frame is set to a Projected Coordinate System. This is a significant problem particularly using Web Mercator.]

I do have another suggestion regarding this issue also.  If you post this on the Ideas forum, where other users can vote on the issue, it will raise the profile of the problem.  The Ideas forum link is:
When using the measure tool you just need to change the measurment type from Planer to Geodesic.

We use the same projection.  

When you open the measurement tool from the drop down Choose Measurment Type select Geodesic as the measurment type.