Our man in Brazil, Mateus Ferreira, has built an Arc10-compatible toolbox called Transect Tool that creates perpendicular transects across a streamline (polyline). Thanks Mateus!
Download Transect Tool –> Transect Tool
Updated December 2014
“Some user reported troubles in use transect tool. I think are problems with Model Builder. Then I changed the tool to a Python code. I changed also the way how to split the line in the same distance. I used a code from here http://www.maprantala.com/2011/05/01/quick-dirty-arcpy-batch-splitting-polylines-to-a-specific-length/ to do this. I think the tool is working better now.” – M. Ferreira, 5Dec2014
Contact the tool’s creator with questions:
Mateus Ferreira (mateusvidotti “at” yahoo.com.br)
Pre-Mateus Workflow Concept by SWC
a.) Input a polyline (a stream centerline)
b.) Segment it at a fixed interval that I specify or segment at the bends (vertices) in the polyline
c.) Convert the segments to points (segment midpoints or endpoints)
d.) Convert these points to perpendicular lines of a length that I specify. Preferably, the lines would have just 2 endpoints (no midpoint vertex).
e.) From there, the transects may be converted to endpoints and elevations extracted, create 3D profiles along these lines, or whatever.
Below are the partial solutions I have found online.