Whole World AIS Site

[freetime]

All world

Live Ships Map - AIS - Vessel Traffic and Positions

and for stockholm, sweden

LIVE AIS STOCKHOLM

[unbusted67]

That is really cool. Are the shaded in areas the only places with ships? It doesn't seem like there are a lot out to sea. I noticed no is around the Somali coast or at least if they are they have their AIS off.

[Paul Elliott]

The shaded areas are where there is AIS coverage and ships have recently been reported. The marinetraffic.com site is fed from many different AIS receivers, usually run by enthusiasts (I am one of these), perhaps locally aggregated, then sent over the internet to their site for display. My AIS receiver is in my barn, overlooking the Pacific north of San Francisco at an elevation of 1000 ft, and I am feeding data to several different networks. There are many other receiver sites in the S.F. Bay area, but (for example) there aren't any between my house and Oregon, so there will be no coverage along that stretch of coast. You will not see much traffic out to sea, since these are land-based receivers and AIS reception is usually line-of-sight. There is work with commercial satellite reception of AIS, but as far as I know this is still at the experimental stage.

There are other loosely organized AIS receiver networks (shipplotter, aishub.net), and some commercial ones as well. This is fascinating stuff.

[Ocean Girl]

thanks for posting this, it is in my favs now.
Erika

[freetime]

If you search ais you can find many differnt sites. Earlier i found one with trains in uk.......

Soon smaller boats will have it to...

[unbusted67]

Originally Posted by Paul Elliott

The shaded areas are where there is AIS coverage and ships have recently been reported. The marinetraffic.com site is fed from many different AIS receivers, usually run by enthusiasts (I am one of these), perhaps locally aggregated, then sent over the internet to their site for display. My AIS receiver is in my barn, overlooking the Pacific north of San Francisco at an elevation of 1000 ft, and I am feeding data to several different networks. There are many other receiver sites in the S.F. Bay area, but (for example) there aren't any between my house and Oregon, so there will be no coverage along that stretch of coast. You will not see much traffic out to sea, since these are land-based receivers and AIS reception is usually line-of-sight. There is work with commercial satellite reception of AIS, but as far as I know this is still at the experimental stage.

There are other loosely organized AIS receiver networks (shipplotter, aishub.net), and some commercial ones as well. This is fascinating stuff.

Ohhhh for some reason, and I know this is wrong, I was thinking AIS was like GPS beaming to satellites and what not. It is only a localized signal though huh?

[Paul Elliott]

The AIS transponders carried by ships and some smaller craft are essentially VHF transceivers, operating on two channels of the marine VHF band. They periodically transmit various types of data, which can be received by close-by receivers.

On VALIS we have a "Class-B" AIS transponder, which is designed more for pleasure craft and transmits a three Watt signal. The big ships (and some pleasure craft) carry "Class-A" transponders, which transmit at 25 Watts. Our AIS antenna is on the upper spreader and we typically see AIS signals from the big ships from 10 - 50 miles off.

My home receiver will reliably receive out to the 50-mile horizon, and if the radio propagation is just right as far as 2000 miles (my record so far).

There are other position-reporting systems out there that do transmit up to satellites, but the AIS system is now required world-wide, and is by far the dominant system. Various gov't agencies and private companies are working on satellite reception of AIS position reports, but as far as I am aware, none of these systems are currently operational.

[donradcliffe]

I think the US government isheavy into satellite tracking of AIS signals, but they aren't sharing.