https://community.esri.com/t5/arcgis-pro-questions/what-is-refractivity-coefficient-in-the-viewshed/m-p/1494293#M84689 <P><A href="https://pro.arcgis.com/en/pro-app/latest/tool-reference/3d-analyst/how-line-of-sight-works.htm" target="_blank">How Line Of Sight works—ArcGIS Pro | Documentation</A></P><P>the reference in the link may be worth consulting if your applications are different than those used by default for the tool</P> Tue, 18 Jun 2024 10:39:41 GMT DanPatterson 2024-06-18T10:39:41Z https://community.esri.com/t5/arcgis-pro-questions/what-is-refractivity-coefficient-in-the-viewshed/m-p/1494262#M84682 <P>Hi all,</P><P>I'm looking to adjust the&nbsp;Refractivity Coefficient in the earth curvature correction to assess visibility for different wavelengths, however I don't understand how this input to the Viewshed tool relates to the physical parameter of refractive index.</P><P>For visible wavelengths in air, the refractive index is close to 1 (<A href="https://en.wikipedia.org/wiki/List_of_refractive_indices" target="_blank" rel="noopener">https://en.wikipedia.org/wiki/List_of_refractive_indices</A>), whereas the default setting of&nbsp;Refractivity Coefficient in the Viewshed tool is 0.13.&nbsp;</P><P>Does anyone know the relationship between&nbsp;refractive index and&nbsp;Refractivity Coefficient?&nbsp;</P> Tue, 18 Jun 2024 08:35:02 GMT https://community.esri.com/t5/arcgis-pro-questions/what-is-refractivity-coefficient-in-the-viewshed/m-p/1494262#M84682 Judith89 2024-06-18T08:35:02Z https://community.esri.com/t5/arcgis-pro-questions/what-is-refractivity-coefficient-in-the-viewshed/m-p/1494293#M84689 <P><A href="https://pro.arcgis.com/en/pro-app/latest/tool-reference/3d-analyst/how-line-of-sight-works.htm" target="_blank">How Line Of Sight works—ArcGIS Pro | Documentation</A></P><P>the reference in the link may be worth consulting if your applications are different than those used by default for the tool</P> Tue, 18 Jun 2024 10:39:41 GMT https://community.esri.com/t5/arcgis-pro-questions/what-is-refractivity-coefficient-in-the-viewshed/m-p/1494293#M84689 DanPatterson 2024-06-18T10:39:41Z