thebebinator

Creating a buffer of a polyline that overlaps itself

Discussion created by thebebinator on Nov 22, 2011
Latest reply on Nov 29, 2011 by Sycosys
Hello all,

I'm getting going on a project analyzing animal movement GPS data, and am running into a problem with buffers. I'm trying to determine the area where an animal revisits more than once. So I'm looking for the area where two buffers (made from the movement polylines) overlap (intersect). I can get it to work for different days' data, but the problem is they can also overlap within the same polyline (same day's data). In this case the buffer dissolves over the entire polyline, losing this self-overlap.

An analogy for city dwellers: picture a road (a single polyline) that curves around under itself. I want to determine the area where a 10m buffer of the road overlaps itself.

Is there any way to make a buffer from a polyline such that it creates a self-overlapping polygon when it overlaps with a later part of the same line? Or perhaps a way to get this same behaviour directly from the intersect tool?

I'm somewhat new to ArcGIS, but have extensive math and computing background. I'm starting get familiar with python and writing scripts, so I'm not scared of going down that path if needed. I've browsed the forums but seems that most ArcGIS users want to get rid of self-intersections, whereas that's what I'm interested in!

Any help would be much appreciated!
Adam Bebko

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