topic Geodesic option on points yields incorrect buffers in ArcGIS Pro Questions

Geodesic option on points yields incorrect buffers

RandyMcGregor_BMcD — Tue, 26 Mar 2024 12:54:39 GMT

Just about sent a map set out, then realized the buffer distances seemed way off (pink, below). I had entered the distances correctly and the coordinate system of the input points was in the coordinates I had assumed. I reran, changing nothing except using 'Planar' and it was correct (blue, below). Geodesic is the default. Is this a bug? is there something that causes this to happen that I should know about?

Thank you,

Randy McGregor

Re: Geodesic option on points yields incorrect buffers

Dale_Honeycutt — Tue, 26 Mar 2024 19:43:38 GMT

The geodesic option is correct. Your map projection (spatial reference) is distorting distances. See these articles:

https://pro.arcgis.com/en/pro-app/latest/tool-reference/analysis/how-buffer-analysis-works.htm

https://pro.arcgis.com/en/pro-app/3.1/tool-reference/spatial-analyst/geodesic-versus-planar-distance.htm

Also, do a web search on "Geodesic vs Planar buffers ArcGIS". You'll find several articles and videos about this.