Determine if a geo location is within geographic area

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Fast answers need clear examples. Post a small Excel sheet (not a picture) showing realistic & representative sample data WITHOUT confidential information (10-20 rows, not thousands...) and some manually calculated results. Just before posting, scroll down to GO ADVANCED, click, and then scroll down to MANAGE ATTACHMENTS and click again. Now follow the instructions at the top of that screen.

still using 2003 Professional ?

Can you post an XLSX file, since I was not able to open it.

This isn't the kind of thing I do, but I think the heart of the algorithm is the "point in polygon" problem: https://en.wikipedia.org/wiki/Point_in_polygon In this case, you solve the "point in polygon" problem for each point and each polygon area.

One "brute force" approach would be to test each point against each polygon and compile the results.

I expect there could be ways to reduce the number of polygons to test for a given point.

I found this UDF that may be useful if you decide to do this in Excel: http://www.excelfox.com/forum/showth...Polygon-Or-Not

Also in my internet searchings, I found this tutorial for a program (claims to be free and open source) called QGIS: https://www.qgistutorials.com/en/doc...n_polygon.html If you are not required to use Excel for this analysis, it might be easiest to use QGIS (or similar) for this analysis.