NASA AIS

[doug748]

I have NASA "Radar" which picks up targets but the max range seems to be about 3 miles - then Pouff, they disappear. Tried fussing with the channel, etc and putting the aerial atop a stick(normally on pushpit) did not seem to improve things.
Any ideas?

 

[Talbot]

Is this a stand alone system?

Even from deck level you should get 7+nm I would suspect the aerial connections.


Please dont call it a radar - it isnt.

 

[fireball]

I had an AIS engine with this problem .... although we had 5Nm ...

Test to eliminate the other parts are:

1) attach it to the known good mast head antenna - little increase
2) attach another AIS device to your kit and test the range - massive increase
3) contact NASA with your findings and ask what your options are ... - mine was repaired and returned .... and now I get 20Nm from my pushpit antenna (usually around 13Nm, but got further today ...)

 

[Sheff]

Similar experience to a friend of mine......... we both installed Nasa Ais engines about the same time. Mine has worked perfectly from day one, his has been "intermittent" at best.

He always suspected the use of an old stubby VHF antenna as being at fault but replacing it with the masthead antenna brought no improvement.

Numerous tests have shown that the odds are it was a dodgy AIS unit from the start.

He is in the process of returning it to Nasa for testing.

 

[Gubbo]

My unit behaved in a very similar manner to yours i.e. limited range and intermittent displays.

I was using a stubby on the pushpit and suspected this to be the cause. I tested this by rigging a brand new whip aerial (destined for the masthead VHF) and found no improvement in performance.

I finally fiddled with the threshold setting and notched it across to the left of the screen. The improvement was quite dramatic, getting reception over 8 miles with the stubby. I have the channel set to alternate A/B scan.

A lot of the signals I receive eminate from vessels operating and moored in Felixstowe so the update rates will naturally vary. I also notice that ships that are clearly docked still broadcast that they are steaming and vice versa.

I'm off across to Holland next week and am looking forward to seeing how the unit performs with isolated vessels, in particular across the shipping lanes. I'm hoping that it will compliment my proper radar as we keep a track on the shipping.

If it's still intermittant then, perhaps it will need a trip back to NASA for a check-up.

 

[doug748]

Thanks for the responses. I shall have another go, and then it may mean a trip back to the makers.

 

[ianwoods]

Hi, Would you let me know which chartplotter you have linked to the AiS? Any simple tips of getting them to comunicate with each other during installation? Thanks

 

[doug748]

Sorry, this is the all in one black box, with screen.

 

[fireball]

We link in with a Standard Horizon CP180i - it is just a matter of connecting the right cables and setting the input port to the right baud setting - oh and a bit of swearing, a few beers and then starting again ... /forums/images/graemlins/grin.gif

 

[DaveS]

But the NASA "all in one box" so-called "RADAR" unit has no output, and can't feed AIS info to a plotter. That said, I have one of these and I've found it OK - range is fine with a good aerial, to return to the original question. And my chart plotter can't take an AIS feed anyway...