makes perfect sense. So you know your container is on a ship...so "trackin= g the container" is really tracking the ship till it gets to port, and then= it can track using cell technology when its on the truck... --- On Thu, 7/1/10, Spehro Pefhany wrote: > From: Spehro Pefhany > Subject: RE: [OT] container tracking > To: "Microcontroller discussion list - Public." > Date: Thursday, July 1, 2010, 8:36 AM > At 11:06 AM 01/07/2010, you 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?=A0 I > can't imagine any other > >way of it > > > working.=A0 Anyone have knowledge on this? > > > >Isn't it done by knowing what ship a container is > placed on? I know > >there are web sites where you can track ships in the > ocean using the GPS > >data they send back (apparently one of the sources of > info Somalian > >pirates use, from what I have heard) but I don't know > the web site > >address. > = > Ships (over a certain size- 300 tons, IIRC) and passenger > ships > are required to transmit their position, bearing and some > other > data regularly (less often when they are docked). The > system is > called "AIS". > = > For example: > = > Flag: Marshall Is > Ship Type: Cargo > Status: Underway > Speed/Course: 7.2 kn / 292 > Length x Breadth: 190 m X 32 m > Draught: 6.7 m > Destination: NEW YORK > ETA: 2010-06-30 17:00 (UTC) > Received (69): 0h 4min 55s ago > = > http://www.marinetraffic.com/ais/ > = > It is a VHF-based system that uses base station receivers, > and > depends on the limited range of VHF. > = > There has been some work using small satellites in LEO to > monitor > ships further out at sea-- it's quite difficult to separate > the > signals from thousands of ships in congested areas such as > the > Mediterranean sea, but apparently possible. > = > I don't know about containers having individual tracking.. > there > have been sophisticated _logging_ devices on containers for > years, > but it would seem to be impossible to either receive GPS > signals > or transmit data to a geostationary, Iridium or whatever > satellite > when a container is buried deep in the bowels of a > container ship, > surrounded by thousands of other steel boxes. > = > Best regards, > = > = > = > = > = > = > = > = > = > >-- > >Scanned by iCritical. > > > >-- > >http://www.piclist.com PIC/SX FAQ & list archive > >View/change your membership options at > >http://mailman.mit.edu/mailman/listinfo/piclist > = > Spehro Pefhany --"it's the network..."=A0 =A0 =A0 > =A0 =A0 =A0 "The Journey is the reward" > speff@interlog.com=A0 > =A0 =A0 =A0 =A0 =A0=A0=A0Info for > manufacturers: http://www.trexon.com > Embedded software/hardware/analog=A0 Info for > designers:=A0 http://www.speff.com > = > = > = > -- = > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > = = -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist