Hi Dave, A major component of shipping is currents, particularly in the open ocean. There are many models available... If I were to propose something, it would need to account for direction and the strength of current. The same could be said for wind, which is harder to anticipate on the small scale/short time frame, but still follows general patterns. The weighting of currents would be far more significant than wind in any model of modern shipping. You can find data on this in many places... Here are two links:
http://oceancurrents.rsmas.miami.edu/atlantic/img_mgsva.html http://oceancurrents.rsmas.miami.edu/atlantic/spaghetti-heading/brazil.j pg Steffan Chmuryk Technical Services Coordinator, ICIS www.icisociety.ca Office: (250) 381-9295 Cell: (250) 516-2481 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, March 05, 2009 5:08 PM To: [email protected] Cc: [email protected] Subject: Re: [postgis-users] Modeling an ocean Hi Dave, I've modelled depths, hydrographic, oceanographic & hydrological data, but never the sort of thing you are talking about. The closest I've come is quantitavely modeling fishing activity, but I had start/finish data for the fishing events there. I guess one way would to be to take something like GEBCO trackline data to work backwards from where ships typically "go". Depth based data will be very problematic in coastal areas, as where traffic is heavy & data good, ships will sail with a metre or so of clearance, and this is very tidal. In less well known areas they may require 10 to 30m of clearance. I also know of current navigational charts where the coast is well over a mile out from reality, so even using those for data is problematic. Can you keep in touch with any progress you make with this? As a PostGIS user in the maritime arena I'm always interested in such things... Cheers, Brent Wood --- On Fri, 3/6/09, David Potts <[email protected]> wrote: > From: David Potts <[email protected]> > Subject: [postgis-users] Modeling an ocean > To: "PostGIS Users Discussion" <[email protected]> > Cc: [email protected] > Date: Friday, March 6, 2009, 2:27 AM > Hi, > > I have been asked to model an Ocean by a 3rd party in terms > of the > possible movement patterns fo ships, has anybody got any > suggestion on > where to start on this issue? > > I am used to think about cost distance models, friction > maps, nearest > neighbour etc on land. But an ocean is a different > concept. Its a fluid > mass which can change density. > > > In terms of sailing its going to have areas such as > sandbank, rocks, > shipwreck sites etc which in terms of land movment patterns > can be > classified as inpassible areas, openwater as flat land > masses. > > Has anybody tried to do anything simalir?, any suggestions > hints etc, > greatly appreciated. > > Dave. > > > -- > Any views expressed in this message are those of the > individual sender, > except where the sender specifically states them to be the > views of the > Pinan Software > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
