I'm trying to compare the spatial distribution between two groups of fishing locations (for each of several different years) in the Bering Sea (lat's ~53 to 65N, long's ~ -178 to -158W. My preliminary explorations have used kernel density estimation (with an unconstrained plug-in bandwidth matrix) and then examined different overlap indices of their home ranges (quantified via utilization distribution overlap index and Bhattacharyya's Affinity) to compare similarities/differences (all performed in R).
However, I'm concerned about the interpretation of these data when the data may span more than one UTM zone. Most of my data are in UTM zone 3 with some data points seeping into zone 4. In more extreme cases, my data may span from zone 1 to 4.
Am I being really ignorant in thinking that I can compare across zone boundaries?
Since I am interested only in relative differences between calculations with the same distortion, will it not matter?
Should I simply make sure that I have my UTM origin set at the southwesterly most point of the data and I'm fine from there?
I've been reading Stack Exchange and other sites all morning and have seen several discussions about measuring across UTM zones, but I haven't been able to logically extend such responses to a method such as this one.