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NASA AIS ("radar")

GHA

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Hopefully somewhere warm
Using AIS data on a plotter is a much better idea than the rather crude Nasa display.
It's been around for a while, when it first came out there weren't really any cheap ais receivers , the nasa filled a gaping hole in the market with a useful piece of cheap kit like they do. I've used one to solo the atlantic when there were not that many other options. Bit of a pain solo compared with todays much more sophisticated alarm option like opencpn. Meant being awake until the target disappeared off the bottom of the screen before the alarm went quiet.
Plus it's standalone so when all the other networked kit goes down or eat far too many amps you can still have ais info.
 
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Plum

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6 Jun 2001
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UK East Coast
I have a boat around 100 metres from me transmitting which I can see on Marine Traffic but there is no indication on my instrument.

As far as I can tell, the antenna is operational (by swapping below with the VHF cable).

Are there any tests I can do to find the problem?

The GPS input is missing as I have mislaid the cable but the instrument declares it is using an historical GPS position.
If you are referring to the NASA AIS "Radar" that has it's own screen (not the NASA AIS engine), then I have just turned mine on without the gps input. Every few seconds it displays a warning message saying no gps and between the warnings there are no targets on the screen.

www.solocoastalsailing.co.uk
 

Plum

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6 Jun 2001
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UK East Coast
Early versions of the NASA thing were only one AIS RF channel at a time, so could lose class B vessels.
No, they do not lose Class B vessels (assuming its been on long enough to pick up their less frequent transmissions) they will receive both Class A and B. Channels A and B are not the mame thing as Class A and B.

www.solocoastalsailing.co.uk
 

TernVI

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No, they do not lose Class B vessels (assuming its been on long enough to pick up their less frequent transmissions) they will receive both Class A and B. Channels A and B are not the mame thing as Class A and B.

www.solocoastalsailing.co.uk
Yes I know that.
I am reporting observed behaviour of one of the earliest units, we know what we saw.
In those days, the AIS radar was a real step forwards, we had one before getting an actual chart plotter.
Displaying AIS signals on a Yeoman Plotter wasn't an option!

Time has moved on and most people wouldn't be starting from there.
I'm pretty sure the firmware has moved on a few times too.
 
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