Is there a way to set measure tool in an ArcGIS Online webmap to measure in a custom projection (i.e. UTM) instead of Web Mercator? I’m trying to get accurate distance and area measurements off of a standard webmap.
No. I don't think this is possible in the current version of ArcGIS Viewer. But this could be a good request for feature. You can submit this to ArcGIS Ideas and if it gets enough votes, you may expect to see it in a future release!
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