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  1. #1
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    Default AIS and Seaclear

    Now Seaclear will accept Nema AIS information has anyone tried it with a AIS signel from a scanner radio.

  2. #2
    steverow's Avatar
    steverow is offline Registered User
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    Default Re: AIS and Seaclear

    You'll need a scanner witha 9k6 output direct from the discriminator.
    Standard audio O/P is not do-able.
    AIS uses GMSK (Gaussian minimum shift keying), a little more fine mouthed than standard FSK.
    I intend to try it sometime over the next few weeks using my FT847 with its 9k6 packet output.

    Steve.

  3. #3

    Default Re: AIS and Seaclear

    Afraid you'll need more than GMSK if you want to demodulate AIS. It is time-domain multiplexed so you will need to synchronise and demux, convert up to 22 different message types from binary to ASCII and then reformat as NMEA VDM sentences.

  4. #4
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    Default Re: AIS and Seaclear

    I think seaclaes accepts the data only through a com port not a sound card, could a Demodulators (pervisell type) be used to imput via a serial port?
    I have got a Tandy Realistic Pro 50 scanner and have modifed it to give a output direct from the discriminator.
    I live too far from the sea so have not been able to try it out yet.

  5. #5
    steverow's Avatar
    steverow is offline Registered User
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    Default Re: AIS and Seaclear

    See also here for a software fixed standalone display:
    http://www.shipplotter.com

    Lots of useful info regarding modems etc.

    Steve.

  6. #6
    trouville is offline
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    Default Re: AIS and Seaclear

    Its not April 1st yet!!!

  7. #7
    steverow's Avatar
    steverow is offline Registered User
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    Default Re: AIS and Seaclear

    I recently e.mailed Ollie at seaclear about use of AIS with NASA engine...
    This is what he sent back:



    --------------------------------------------------------------------------------


    --------------------------------------------------------------------------------

    Subj: Re: Thanks for AIS
    Date: Sat, 12 2 2005 8:36:34 pm GMT
    From: "SeaClear" <seaclear@sping.net>
    To: <G1FIP@
    Reply-To: "SeaClear" <seaclear@sping.net>
    Sent from the Internet (Details)



    Hi,

    SC reads NMEA binary VDM messages which is standard output from AIS devices.
    I do not know about the NASA unit, better to ask them, SC is freeware so
    easy for them to test.

    CCS was really created for screen capturing, propably Panavue is better
    suited for scanning.


    /Olle

  8. #8
    Oldhand is offline Registered User
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    Default Re: AIS and Seaclear

    I have ShipPlotter under test at home using the "Packet" output from an ICOM PRC1000 receiver fed into the PC microphone input. With a 15k IF bandwidth selected I get reasonable decoding even though I'm using an HF long wire antenna that's totally unsuitable for VHF reception. However its good enough to watch the traffic around the Poole Harbour area from 4 miles inland. [img]/forums/images/graemlins/wink.gif[/img]

  9. #9
    trouville is offline
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    Default Re: AIS and Seaclear

    can i do the same with my icom 706 mk2??

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