Marine Electronics Forum - AIS offshore .... realtime data

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View Full Version : AIS offshore .... realtime data


bluewaterpirate
03-24-2012, 08:36 AM
Our day didn't go as planned orginally we were heading offshore to fish but got a late start because of a throttle linkage issue. We got it corrected so we decided to use the day as a shakedown cruise in as much as we had a new electronics install and really just needed to run the boat.


The weather was spectacular clear and warm with calm seas. We departed the Beaufort Inlet at 11am and ran to AR305 and 240 Rock area 30 miles south the inlet. The water turned a deep blue at 7 miles and remained crystal clear throughout the day.

We trolled back toward the south side of Big/Little 10 where I conducted some radio checks using SeaTow's automated radio check system (channel 27) .... works great solid comms on both radios at 22 miles from the tower.

In the process I noticed four AIS contacts being displayed on my Garmin & Simrad chartplotters. The AIS data was being sent to my CP's by my SH GX2100 VHF. The two northern contacts in close proximity were in the anchorages just southeast of the inlet (17 miles from my location), another one moored at the port in Morehead City (20 miles from my location), and the other 9 miles eastnortheast of my me.

That's real good range reception via AIS. ;)
Here is a video and display screenshots from my Garmin 740.

http://bluewaterpirate.phanfare.com/5510710_6254309

Garmin 740 display screenshots .....

http://i676.photobucket.com/albums/vv129/bluewaterpirate/Simrad%20NSS8%20Sonar%20Pictures/23MAR12_1213_00-1.jpg?t=1332598291


Here's larger chart display of the AIS contact in MHC. This screenshot was taken as we returned to the marinia. The ship is just north and a little west of my location


http://i676.photobucket.com/albums/vv129/bluewaterpirate/Simrad%20NSS8%20Sonar%20Pictures/23MAR12_1516_00.jpg?t=1332542489


Bonus pictures ... some Simrad NSS8 embedded sonar conneted to an Airmar TM 260.

http://i676.photobucket.com/albums/vv129/bluewaterpirate/Simrad%20NSS8%20Sonar%20Pictures/shot108.png?t=1332542186

http://i676.photobucket.com/albums/vv129/bluewaterpirate/Simrad%20NSS8%20Sonar%20Pictures/shot86.png?t=1332542149

http://i676.photobucket.com/albums/vv129/bluewaterpirate/Simrad%20NSS8%20Sonar%20Pictures/shot67.png?t=1332542128


There you go .........


capecuddy
03-24-2012, 08:45 AM
AIS works great...I have the GX-2150 and pull in some pretty distant targets as well.

I saw a tanker heading for Boston as I was offshore from Chatham. He was out at the VTS lane...about 10 miles out. after a few seconds I then saw the radar paint him right over the AIS triangle. Good illustration of alignment among GPS, chart, AIS and radar.

One nice thing about those AIS targets is that they show the MMSI of the vessel as well in the event you needed to hail, a great way to do it via DSC.

vettnman
03-24-2012, 10:22 AM
Tom, I've never heard of a AIS target. Can you explain?


gerg
03-24-2012, 12:10 PM
AIS is Automated Identification System. Basically, all commercial ships over a certain size must use it, and many recreational boats and smaller commercial boats use it voluntarily.

It works by sending a coded signal using vhf frequencies at regular intervals (~5 seconds for class A, 30 for class B). The information contains ships id (MMSI and name), direction, speed, size, destination and origin (for class A).

Boats transmitting that info can be displayed as targets on a chartplotter if you have an AIS receiver.

It's the same basic technology they use to keep track of planes in the air.

You can buy receiver only units (like the kind built into some VHF units) or transmitter/receivers.

Very useful technology. The furthest I've seen an AIS target ID'd was over 100 miles out. That had to be a class A unit (xmits with more power from a higher position like on the top of a container ship) plus some sort of atmospheric skipping. Useless info, but it was cool to see it in the list.

bluewaterpirate
03-24-2012, 12:40 PM
This is one of the three data pages I pulled up on the one moored in MHC. All you do is when you see one one is touch the contact on my 740 all the info is listed.

http://i676.photobucket.com/albums/vv129/bluewaterpirate/Simrad%20NSS8%20Sonar%20Pictures/23MAR12_1517_00.jpg?t=1332542493

vettnman
03-24-2012, 12:55 PM
Thx guys. That's some cool info. I like it.

nicktg
03-24-2012, 01:08 PM
BWP,

Looks like your SonicHub is ... still initializing :grin:
What's up with that?

bluewaterpirate
03-24-2012, 01:12 PM
I had turned it off and because I dodn't deselect from the NSS8 it continues to look for it.

Ethan
03-24-2012, 02:43 PM
Comes in very handy in the fog. You can see what your up against.

http://i532.photobucket.com/albums/ee324/fissues/GarminAISScreenshots001.jpg

http://i532.photobucket.com/albums/ee324/fissues/GarminAISScreenshots002.jpg

http://i532.photobucket.com/albums/ee324/fissues/GarminAISScreenshots004.jpg

Crabpot Man
03-24-2012, 03:44 PM
Our day didn't go as planned orginally we were heading offshore to fish but got a late start because of a throttle linkage issue. We got it corrected so we decided to use the day as a shakedown cruise in as much as we had a new electronics install and really just needed to run the boat.


The weather was spectacular clear and warm with calm seas. We departed the Beaufort Inlet at 11am and ran to AR305 and 240 Rock area 30 miles south the inlet. The water turned a deep blue at 7 miles and remained crystal clear throughout the day.

We trolled back toward the south side of Big/Little 10 where I conducted some radio checks using SeaTow's automated radio check system (channel 27) .... works great solid comms on both radios at 22 miles from the tower.

In the process I noticed four AIS contacts being displayed on my Garmin & Simrad chartplotters. The AIS data was being sent to my CP's by my SH GX2100 VHF. The two northern contacts in close proximity were in the anchorages just southeast of the inlet (17 miles from my location), another one moored at the port in Morehead City (20 miles from my location), and the other 9 miles eastnortheast of my me.

That's real good range reception via AIS. ;)
.........

That range shouldn't surprise you at all.

First. SeaTow typically locates their ARC antennas at 30' AGL. I would think most large commercial vessels would have their communications antennas at least that high, if not higher.

Second, AIS Class A transceivers have 12 watt outputs on a TDMA carrier, requiring a receiver to receive only a short burst of digital data.

Couple those two together and I would expect AIS to reach out as far, or farther than SeaTow's ARC.

Cool pictures. :thumbsup:

Ethan
03-24-2012, 03:57 PM
This is my boat picked up by Homeland Security in New York and sent to me by email.
I was on Stellwagen Bank, 200 miles away. I'm only running 3 watts.

They use a UHF band and bounce it also using roving repeaters on USCG, Pilot and Survey vessels.

http://i532.photobucket.com/albums/ee324/fissues/fissuesaispicnew.jpg

Ethan
03-24-2012, 04:04 PM
I also watch the fishing fleet at the canyons to check their patterns. That is quite a distance also.

http://i532.photobucket.com/albums/ee324/fissues/CanyonShot3.jpg

mscontender
03-24-2012, 04:15 PM
Thanks for posting. I just added the Furuno FA50 (transmit and receive) to my system. In the northern gulf of Mexico where I fish there does not seem to be many recreational boats that have adopted the technology as yet, at least not the ones that transmit. However, we fish around offshore oil rigs a lot and all the boats associated with the rigs use AIS. Knowing there vessel name makes talking to them much easier.



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