Finding Closest Distance Between Points

[JontyKnox]

Hi,

I have a .shp file representing global shipping ports. Basically I want to find which two ports or points are closest.

This is the first stage of an analysis and I would be happy to settle with this. On the off chance someone has a solution however, there is a slightly more complicated dynamic:

The crux of the matter is that the ports have to be closest to each other on the sea, so any distances calculated over land wouldn't suffice.. I'm assuming I would have to use come continental shapefile as a barrier to distance calculations, but I'm in the dark as to how I should go about this.

Finally, the port data I have is incredibly accurate and the majority of continental .shp files I have downloaded so far aren't. So when I try and marry the two together quite often the sea ports appear to fall inland on some of the continents. If anyone can recommend a high resolution continent shapefile that would correspond with the accuracy of my port data I would also really appreciate it.

Thanks,
Jonty Knox

[DarrenWiens2]

I'd suggest treating this as a Least Cost Path Analysis, where travelling over land is prohibitively costly.

[JontyKnox]

That worked fine for that element of the project but I have another similar step that I'm struggling with:

Essentially I have two different Point .shp files and I need to find the nearest neighbors to one point shapefile using the other. For example, I have 7 species sightings at various locations and I need to identify the nearest ports to those species sightings. The nearest neighbor tools in Arc only allow for one .shp file input, not the two .shp files I require in this case.

Thanks, Jonty

[DarrenWiens2]

Have you tried the Near tool? Requires ArcInfo.