BUG-000140486 for ArcGIS Online

Bug ID Number	BUG-000140486
Submitted	June 4, 2021
Last Modified	August 6, 2025
Applies to	ArcGIS Online
Version found	9.2
Operating System	Windows OS
Operating System Version	10.0
Status	Known Limit

Additional Information

The slope values appear inaccurate when working with short elevation profiles. Higher resolution profiles are downsampled to a 10m (32.8ft) sampling distance before the slope is calculated. Refer to https://developers.arcgis.com/javascript/latest/api-reference/esri-widgets-ElevationProfile-ElevationProfileLine.html#statistics This is because the elevation preview model (EPW) was initially created for measuring profiles of larger areas with coarser elevation data. The default elevation services are not precise enough and can have a lot of noise in the dataset. This may result in the generation of false reports, e.g. too steep maxSlope values.

Workaround

For calculating the slope value of more precise datasets, iterate through the list of ElevationProfileSamples of a ElevationProfileViewModel and calculate the maximum and average slope values from that. Refer to an example here, https://codepen.io/gsoosalu/pen/MWoGMOe However, it is not possible to overwrite the widget’s legend (the numeric reports) with the new values, i.e. the out-of-the-box legend must be hidden. Refer to https://developers.arcgis.com/javascript/latest/api-reference/esri-widgets-ElevationProfile.html#visibleElements and the newly calculated ones are displayed in a container outside of the widget. The line graph visualization remains accurate because it is drawn based on the data from the ElevationProfileSamples.