https://community.esri.com/t5/implementing-arcgis-questions/polyline-length-diffrent-in-arcgis-desktop-vs/m-p/1692710#M802 <P>Hi, I am in the process transitioning over to Pro (3.6.2) from Desktop (10.8.2). So I am trying to train myself to use Pro after work.&nbsp; I have noticed a problem with polyline length.&nbsp; I have a polyline that reports a length that is almost a mile longer in Pro than it is in Desktop.&nbsp; The project in Desktop and Pro is in the CA State Plane Zone III feet projection.&nbsp; The polyline is also in the same coordinate system.&nbsp; I did not make any edits to the polyline.&nbsp;</P><P>I added the polyline to a new project in Pro, which is the centerline of a river, and brought in a bathymetric raster of the river, which is also in the same coordinate system.&nbsp; I plotted the profile of the line from the raster bathematic data. by right clicking on the raster data set and selecting the polyline for the profile.&nbsp; The profile plot in Desktop is 37,174 feet long, and the profile of the line in Pro is 42,190 feet long.&nbsp; That is over 5,000 foot difference, almost a mile longer in Pro!&nbsp; The raster dataset that I am using covers much more area than the polyline, so there should not be any clipping going on.&nbsp; Both profiles have an elevation point assigned every 10 feet along the polyline.</P><P>Using the same aerial photograph as a base map in both programs, which is also in the same coordinate system, zooming in, the polyline appears to start and stop at the same location in Desktop and Pro.</P><P>I have also tried measuring the polyline in Planer and Geodesic format in both programs and each program basically produced the same result, with a minor change between Planer and Geodesic that you would expect for such a short distance.</P><P>Does anybody have any idea what might be going on?</P> Thu, 26 Mar 2026 00:44:31 GMT Hydrad 2026-03-26T00:44:31Z https://community.esri.com/t5/implementing-arcgis-questions/polyline-length-diffrent-in-arcgis-desktop-vs/m-p/1692710#M802 <P>Hi, I am in the process transitioning over to Pro (3.6.2) from Desktop (10.8.2). So I am trying to train myself to use Pro after work.&nbsp; I have noticed a problem with polyline length.&nbsp; I have a polyline that reports a length that is almost a mile longer in Pro than it is in Desktop.&nbsp; The project in Desktop and Pro is in the CA State Plane Zone III feet projection.&nbsp; The polyline is also in the same coordinate system.&nbsp; I did not make any edits to the polyline.&nbsp;</P><P>I added the polyline to a new project in Pro, which is the centerline of a river, and brought in a bathymetric raster of the river, which is also in the same coordinate system.&nbsp; I plotted the profile of the line from the raster bathematic data. by right clicking on the raster data set and selecting the polyline for the profile.&nbsp; The profile plot in Desktop is 37,174 feet long, and the profile of the line in Pro is 42,190 feet long.&nbsp; That is over 5,000 foot difference, almost a mile longer in Pro!&nbsp; The raster dataset that I am using covers much more area than the polyline, so there should not be any clipping going on.&nbsp; Both profiles have an elevation point assigned every 10 feet along the polyline.</P><P>Using the same aerial photograph as a base map in both programs, which is also in the same coordinate system, zooming in, the polyline appears to start and stop at the same location in Desktop and Pro.</P><P>I have also tried measuring the polyline in Planer and Geodesic format in both programs and each program basically produced the same result, with a minor change between Planer and Geodesic that you would expect for such a short distance.</P><P>Does anybody have any idea what might be going on?</P> Thu, 26 Mar 2026 00:44:31 GMT https://community.esri.com/t5/implementing-arcgis-questions/polyline-length-diffrent-in-arcgis-desktop-vs/m-p/1692710#M802 Hydrad 2026-03-26T00:44:31Z