Exclusions in a density analysis

Discussion created by msmith200 on Jun 26, 2012

I am trying to create a kernal density raster from fish harvest data.  The data comes from areas that people have circled, which is converted to a point layer.  The problem is that when people circle an area, a marine or river area, the edges of the circles include land areas.  I want to exclude these land areas from the density analysis, since we can assume people aren't fishing on the hill tops.  I tried making those points on land equal to zero, but since the search radius is large in the density analysis, areas on one side of a peninsula/land point affect areas on the other side of the peninsula, drawing values over land.  I also tried using a mask in the environment settings, but that effectively gives me the exact same output, with the values on one side of the point still affecting those on the other side, the only difference is that land areas equal NoData.  So the mask isn't being considered in the density analysis process, but only in the output.  I want to exclude land areas from the actual density analysis, so they are not considered in the process, so the search radius is blocked from including land areas, which will show a lot of use around a peninsula, but not on the land areas.  Any advice would be much appreciated.  Thanks!