I have Arc 10.0 and I'm using the Interpolation with Barriers/Kernel Smoothing to generate a surface to predict oil concentrations in water. The reason I'm using an interpolation w/ barriers is because the coastline is serving as a barrier.
At first I was using the default bandwidth (search radius), until I realized it was somewhat arbitrarily defined as "...the shortest of the width or height of the output extent in the output spatial reference, divided by 30." http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//009z0000000s000000.htm Now I've been trying to decide if I should define the bandwidth myself.
One issue I'm having is that I don't know the UNITS for the bandwidth! My dataframe is set to km, but there's no way the bandwidth units are in km, because the number is too small (the average distance between my points is ~10 km, but the default bandwidth is on the order of 0.1).
Qualitatively, the interpolation with the default bandwidth looks good. Not too "spiky" or too "smooth". But I want to publish this eventually and so I'm hoping to have a better understanding of this, and to choose a more appropriate bandwidth if necessary.
