Marinetraffic AIS Reporting Stations.

[BrianH]

I have recently noted that my position shown by Marinetraffic on their map site is provided by "AIS Source 3" as are some others in my area, although others are sourced from the usual receiver 44 in Koper, Slovenia, that historically covers our area. The station number can normally be clicked on for statistical data on its reception performance but with AIS Source 3, doing so brings up a 404 error.

Searching around for other Source 3 reported targets I find a widely diverse target list, including the south Atlantic. Clearly reports are now being provided from satellite data, which appears not to be just reserved for their subscription service.

 

[RichardS]

I have recently noted that my position shown by Marinetraffic on their map site is provided by "AIS Source 3" as are some others in my area, although others are sourced from the usual receiver 44 in Koper, Slovenia, that historically covers our area. The station number can normally be clicked on for statistical data on its reception performance but with AIS Source 3, doing so brings up a 404 error.

Searching around for other Source 3 reported targets I find a widely diverse target list, including the south Atlantic. Clearly reports are now being provided from satellite data, which appears not to be just reserved for their subscription service.

Can the AIS transmission from a boat be picked up by a satellite? I appreciate that it's line of sight but it's a long way away. Although, having said that I sometimes pick up the AIS signal from boats 400 or 500 miles away so the signal is bouncing off some layer in the atmosphere so it can travel a long way.

Although my AIS antenna is at the top of a 20m mast I do not register on Marinetraffic at all when I am in Kremik marina no matter how long I transmit for. As soon as I travel a few hundred metres towards the open sea, I appear! I must be in a shadow created by the hills so satellite reception might resolve this eventually.

Richard

 

[prv]

Can the AIS transmission from a boat be picked up by a satellite? I appreciate that it's line of sight but it's a long way away.

I don't actually know what their respective power outputs are, but nobody seems surprised that a PLB signal can make the same journey

Pete

 

[RichardS]

I don't actually know what their respective power outputs are, but nobody seems surprised that a PLB signal can make the same journey

Pete

True!

Richard

 

[ianj99]

I don't actually know what their respective power outputs are, but nobody seems surprised that a PLB signal can make the same journey

Pete

Mr Google says Class A tx power is 12.5watts and B, 2watts.

Satellites must have amazingly sensitive receivers. My internet connection is via a 2way satellite link to eutelsat 3, 32000km away and the transmitter power is also only a few watts, (although there is a 15" dish to focus it.) and it is rarely affected by whatever the weather, even heavy snow.

 

[prv]

Mr Google says Class A tx power is 12.5watts and B, 2watts.

Thanks. And for comparison, it looks like a typical PLB is 5 watts, same as a VHF handheld.

Pete

 

[BrianH]

Although my AIS antenna is at the top of a 20m mast I do not register on Marinetraffic at all when I am in Kremik marina no matter how long I transmit for. As soon as I travel a few hundred metres towards the open sea, I appear! I must be in a shadow created by the hills so satellite reception might resolve this eventually.

I suspect it can resolved NOW Richard. I presume you already have an account with Marinetraffic - at least the free registration as I have. If so, log on, go to 'My Account' and enter your vessel into My Fleet if not already in. At the end of the entry you will now see "OFF ON SAT X" where you can toggle between OFF and ON.

Edit:
I may have made an assumption too far in interpreting AIS Source 3 as being satellite target reporting, as further research reveals Marinetraffic has station id. that are hidden (and invoke the 404 response) because they are bi-directional aggregate feeds maintained with other AIS data providers. However, the good news is that for non-subscribers satellite reporting is enabled for a single vessel:
"Follow vessels via Satellite. Sat-AIS data are bundled with data reported by our terrestrial network. Please note that Sat-AIS coverage might not be very effective with Class B transponders (usually installed in smaller vessel such as sailing boats)."

 

[RichardS]

I suspect it can resolved NOW Richard. I presume you already have an account with Marinetraffic - at least the free registration as I have. If so, log on, go to 'My Account' and enter your vessel into My Fleet if not already in. At the end of the entry you will now see "OFF ON SAT X" where you can toggle between OFF and ON.

Edit:
I may have made an assumption too far in interpreting AIS Source 3 as being satellite target reporting, as further research reveals Marinetraffic has station id. that are hidden (and invoke the 404 response) because they are bi-directional aggregate feeds maintained with other AIS data providers. However, the good news is that for non-subscribers satellite reporting is enabled for a single vessel:
"Follow vessels via Satellite. Sat-AIS data are bundled with data reported by our terrestrial network. Please note that Sat-AIS coverage might not be very effective with Class B transponders (usually installed in smaller vessel such as sailing boats)."

Thanks for that. I've just tried putting AJAY into a fleet and although it picks her name up from when she was last on the display (although with an HR rather than UK country code because since I changed the MMSI number to a UK one I've not left the marina!) it says there is an error when I try to add her to the fleet.

I'll try next time I'm actually live on the Marinetraffic display as I should then show also as UK registered.

Richard