Coordinate Mismatch between ArcGIS Pro and QGIS

AshrafulAnik

Hello Esri Community,

I am working on a project with a dataset of 611 addresses, and I’ve encountered a problem when selecting features by location. In ArcGIS Pro, the selection works as expected—when I select by location, it selects the correct feature. However, when I attempt the same process in QGIS, the feature is not selected, even though the XY coordinates are identical in both software.

Both ArcGIS Pro and QGIS show 7 decimal places for the XY coordinates, but ArcGIS Pro seems to handle the rounding or precision slightly differently. The coordinates for the point and the corresponding vertex of the line match perfectly in ArcGIS Pro, but QGIS does not select the feature as expected.

I have ensured the coordinate system is consistent across both platforms. Despite this, the issue persists, and I am unable to figure out why QGIS is not selecting the feature.

Has anyone experienced a similar issue? Any insights on why this might happen, or suggestions on how to resolve it?

I appreciate any help or advice from the community!

Thank you!

VinceAngelo

Part of the issue here is probably that ArcGIS uses a sophisticated model to store coordinates, in effect, snapping the vertices to a very fine sub-millimeter grid. The exact details are covered in the Understanding Coordinate Management in the Geodatabase whitepaper, but the gist of it is that a SpatialReference object is a lot more than the coordinate system -- It includes the exact parameters for the vertex grid (and it's variable, and the default values have evolved over time, so depending on when and how the dataset was created and referenced, it could be different from site to site).

It's probably not as useful to ask in Esri Community why the non-Esri app is behaving that way that it is -- GIS Stack Exchange might be a better forum, but in order to ask a more specific Question, you should probably review the whitepaper, so you know which details to add.

- V