Author Topic: Marinetraffic.com has some operational quirks  (Read 8027 times)

Offline jimbo123

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Marinetraffic.com has some operational quirks
« on: February 16, 2011, 09:52:17 AM »
I quite like the marinetraffic.com site, but I've noticed some quirks. I don't know if they are bugs or side-effects of radio transmissions.

For example, I am tracking the cargo vessel ITALY EXPRESS. Its current position is steaming up the east coast of North America en route between the ports of New York and Halifax.

According to marintraffic.com, the most recent report of its position has been made by AIS station with ID 276, which according to the site is based in Norway! Station 226 "BARM" reportedly has radio capabilities of:- Max: 9.38 N miles, Average: 1.63 N miles, and coverage of 861 sq km, yet Olso (for instance) is 2700 nautical miles from New York.

Either station 276 is not in Norway, or the VHF AIS signal from ITALY EXPRESS is traveling a l-o-o-n-g way!
« Last Edit: February 16, 2011, 09:54:21 AM by jimbo123 »

Offline jimbo123

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Re: Marinetraffic.com has some operational quirks
« Reply #1 on: February 16, 2011, 10:04:48 AM »
*** Update ****

On looking up BARM's stats tonight I see they are different from the ones I recorded yesterday. They now read:

Reception distance in nautical miles: Average: 599.44 / Max: 1533.82
Area Covered: 186714 square km

... so that's some reach!

Don't know why that station's data is different today; must be another quirk.

« Last Edit: February 16, 2011, 10:08:33 AM by jimbo123 »

Offline jimbo123

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Re: Marinetraffic.com has some operational quirks
« Reply #2 on: February 16, 2011, 11:14:32 AM »
Marine Traffic do state that an hour should be allowed which implies that information supplied should not be used as being current or indeed complete but from my own experience the information they give is fairly reliable, I don't think it should be used as a definitive site and yes, they do have the occasional quirk.

Hi Ken,

Yes I had noted the one hour bit. Oftentimes it's more than one hour because I guess the closest station(s) go offline, or the ship is out of range of one of the stations.

I'm simply interested in getting an idea of the range of the receiving stations, but quite a few of them are unlisted -- my count at the moment is some 103 station numbers between 1 and 799 without names and coverage data.

As I've noted in another thread, at least 4 of those "anonymous" station IDs have appeared during my tracking of the voyage of ITALY EXPRESS.

Offline Glenn Towler

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Re: Marinetraffic.com has some operational quirks
« Reply #3 on: February 16, 2011, 11:12:43 PM »
Intresting down here in Tasmania, in Hobart there are 2 station that I know of: 1 an amatuer radio operator and the second: is from Marine and Saftey Tasmania.  Neither recivers are frequently turned on, so we can got for weeks or often months with out it showing anything in Hobart.

But strangley on a very clear day with minimal cloud in Tasmania the reciver at the Australian Maritime College at Bell Bay at the other end of the State a good 3 hour drive from Hobart picks up the signals from the ships in Hobart.
...

Offline jimbo123

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Re: Marinetraffic.com has some operational quirks
« Reply #4 on: February 17, 2011, 05:46:30 AM »
Intresting down here in Tasmania, in Hobart there are 2 station that I know of: 1 an amatuer radio operator and the second: is from Marine and Saftey Tasmania.  Neither recivers are frequently turned on, so we can got for weeks or often months with out it showing anything in Hobart.

Receivers may be online but the data feed may not be working. Possibly nobody checking it.

Yes, for what is essentially a line-of-sight transmission technology, VHF can certainly get around when the conditions suit.

Offline Sinisa Aljinovic

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Re: Marinetraffic.com has some operational quirks
« Reply #5 on: February 17, 2011, 08:16:45 AM »
They have had an issue on server side affecting UDP connections last week or so.We can't expect perfect 24/7 service for something running on voluntary basis and for free.If you live near the shore,island or busy river, would like to take a part and expand AIS reception please visit http://www.digital-seas.com/open_space/sharing_ais/add_your_area.html
You could get equipment for free and become sharer as well.
If you are not interesting, maybe your friend or amateur-radio operator you know could give a 10 cents to any AIS projects.

     Regards

Offline jimbo123

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Re: Marinetraffic.com has some operational quirks
« Reply #6 on: February 17, 2011, 10:27:46 AM »
If you live near the shore,island or busy river, would like to take a part and expand AIS reception please visit http://www.digital-seas.com/open_space/sharing_ais/add_your_area.html

If I were close to the water or on a mountain I'd be glad to assist. However I'm way inland, and I don't know any ham operators either. Nonetheless, I'll keep it in mind in case I get the opportunity to interest somebody who resides in one of those key locations.

Offline St. Elsewhere

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Re: Marinetraffic.com has some operational quirks
« Reply #7 on: August 21, 2013, 10:43:32 PM »
I would like to better understand the AIS Station codes that are displayed when you click on a target.  For most of the targets the information that appears when you click on them shows something like "Received (1729)".  And when you search the Station ID List for 1729, information appears on the station that is the source of the target data.

I have found that there are various Station ID's that do not appear on MarineTraffic.com's Station ID list.  I have learned a little about what two of them mean:

Received (1) means that the source is from another web site's data base, but I do not know whose site is supplying it.

Received (25) aprs.fi means that the data is from an amateur radio equipped vessel that is sending AIS data via VHF radio to a land based ham station that puts the data on the internet.  I would have added a link here to a wiki description of aprs.fi, but I have not figured out how to make hyper-links work on this site yet.

There are other Received (Station ID's) such as 888 and others that I do not understand.  Can you please provide additional Station ID definitions?
« Last Edit: August 21, 2013, 10:58:32 PM by St. Elsewhere »

Offline Sinisa Aljinovic

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Re: Marinetraffic.com has some operational quirks
« Reply #8 on: August 22, 2013, 05:17:11 AM »
I think that you are on wrong web page asking for details.You had better to place your comment at Marine Traffic forum or send them e-mail. :o

Offline Phil English

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Re: Marinetraffic.com has some operational quirks
« Reply #9 on: August 22, 2013, 08:11:44 AM »
Yes - Sinisa is right. It's really a query best directed to marinetraffic.com as it relates specifically to their data

Brgds
Phil
« Last Edit: August 22, 2013, 08:33:12 AM by Phil English »

 

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