A vaguely similar approach is provided by the (hard to use) code in the tripEstimation package. This package is primarily for determining realistic track locations from raw archival light data or satellite locations with estimates included for the "intermediate path" between data collection times, but the methods used to apply auxiliary data such as SST or bathymetry, and simple speed models could be applied to your case. I'd be happy to try an example to see if the existing code can be applied, although it might be a bit heavy handed. Is there a freely available coastline data set that you would be confident using in your case? Is the GSHHS sufficient? Do you have other data that can be used to limit the likely/possible path? Some more context for the package via an (out of date) light example can be found here: http://staff.acecrc.org.au/~mdsumner/Rutas/tripEstimation-demo.pdf Cheers, Mike. --On Thursday, 18 December 2008 2:38 PM -0500 Jon Loehrke
<jloehrke at umassd.edu> wrote:
Hi, I am trying to find an algorithm or thoughts on approach for how to compute the shortest realistic distance between two points. I define shortest realistic distance as the shortest distance between two points that a fish (which is what I study) could move through. Hence the path must wrap around land, islands, archipelagos, etc. Point 1 41.15 N 71.26 W Point 2 42.17 N 70.37 W I'm sure this issue has come up with the geo-statistical community, but simply need a starting direction. Thank much and happy holidays. Jon Loehrke Graduate Research Assistant Department of Fisheries Oceanography School for Marine Science and Technology University of Massachusetts 200 Mill Road, Suite 325 Fairhaven, MA 02719 jloehrke at umassd.edu T 508-910-6393 F 508-910-6396
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