The containers are steel, sealed pretty tightly, probably an inside the container GPS isn't going to get the signal. Would need an external antenna, and then where the container is stowed in the ship could be an issue, if it's down in the hold, surrounded with other containers and ship steel that signal isn't going to get there. But it is known that certain hazardous containers just might be placed on top, and near an edge of the ship where the troublesome container just happens to get lost at sea. :) On 7/2/2010 11:48 AM, Alex Harford wrote: > On Thu, Jul 1, 2010 at 7:40 AM, alan smith wrote: > >> Curious if anyone knows for ocean container tracking, obviously they use a GPS module to get the location, but for transmitting data back to the "home" monitoring station, I would assume that a single satellite transmitter collects data via wifi or some other network from each GPS unit? I can't imagine any other way of it working. Anyone have knowledge on this? >> > William Gibson may be able to answer that for you. One of his newer > books involves this stuff: > http://www.williamgibsonbooks.com/books/spook.asp > > :) > > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist