Distance accumulation

[JYP]

Hello, I'm currently working with Distance Accumulation in ArcGIS Pro. I aimed to calculate the actual surface distance from my point data, so I input a DEM raster as the surface raster. It produced results, but I'm unsure if it considered elevation properly. When I changed the symbology of the result from stretch to classify, it appeared as perfect concentric circles, which doesn't seem realistic. I'm uncertain if this result is acceptable. Is there any way to verify if it was calculated correctly or if I missed something? Also, should my points have z-values before using the distance accumulation tool? 

[DanPatterson]

Distance Accumulation (Spatial Analyst)—ArcGIS Pro | Documentation

How distance accumulation works—ArcGIS Pro | Documentation

What parameters are you using?

An image of your inputs and results would help

[xiangyudong]

we have the same question. I put  “input feature source”,"input surface raster(dem)" and "maximum accumulation(5km)".Only these data.   If dem is projected coordinate systems. The result was a circle.

If dem is geographic coordinate system. The result looked like the actual distance, but the range is not 5km.

Could you help me? Thank you very much.