topic Re: measure distance in UTM in ArcGIS JavaScript Maps SDK Questions

measure distance in UTM

anjelinaponkerat — Sat, 16 Nov 2019 16:28:04 GMT

The measure tool can not measure length in the UTM system. The web_Mercator system represents lengths greater than the actual value. Is there a solution to solve problem?

Re: measure distance in UTM

Noah-Sager — Mon, 18 Nov 2019 18:10:19 GMT

Hi Anjelina, I'm not sure I understand what's not working. I think the Measurement widget works with all coordinate systems and projections. Do you have a simplified reproducible test case you could share?

Re: measure distance in UTM

anjelinaponkerat — Wed, 20 Nov 2019 19:07:13 GMT

The measurement tool calculates the distances in the web-mercator system and shows the distances more than the actual value. The measurement tool needs to have settings that allow you to select the UTM projection to calculate the length. Is there any solution?

Re: measure distance in UTM

Noah-Sager — Wed, 20 Nov 2019 19:25:53 GMT

There is no way to set a specific projection with the measurement widget.

However, you could modify the threshold on the measurement widget's view model to ensure the measurement is performed planimetricllay. From Measurement | ArcGIS API for JavaScript 4.13 :

For 2D MapViews, distances are computed geodetically for geographic coordinate systems and web mercator. For non-web mercator projected coordinate systems, computations will be performed planimetrically for distances up to the threshold distance defined by the geodesicDistanceThreshold property of the widget's ViewModel. Distances equivalent to and beyond the threshold will be computed geodetically. By default the threshold is set to 100km.

Another option would be to use the geometryEngine to calculate distances.

If you still need help, please share a simplified code example showing the issue you are facing.

Re: measure distance in UTM

NathanBruce1 — Wed, 03 Jun 2020 14:50:18 GMT

Hello

We are typically seeing the opposite, that Web Mercator lines are shorter than UTM NAD 83.

Do either of these older posts help? Or were you able to resolve what your were seeing.

How to change the projection in ArcGIS Online in one easy step

https://community.esri.com/message/844046-re-wgs-1984-web-mercator-auxiliary-sphere-measurement-issues?commentID=844046#…