AIS Ships alot of @

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Micheal Spiers (Niveous - VA7MAD)

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Jul 14, 2024, 4:26:14 PMJul 14
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This is weird ,  when I look at AIS info some have extra @ added


Screenshot 2024-07-11 212227.png

OH1KH Saku

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Jul 16, 2024, 2:47:14 AMJul 16
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The receiving station has not filtered out @. It seems that AIS transmitters will send @ as fill character if the ship name definition is not made properly.
Or otherwise it is some AIS transmitter brand property because not all ship names, even short ones, do not have @-filler.

When I was setting up my AIS receive station with DireWolf program I noticed the same with some ships. I had to do @ filtering before sending them to arps.fi to get rid of names with @@@ strings.

Klaus Lohmann

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Jul 18, 2024, 3:37:24 AMJul 18
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The 'Vessel Name Field', as in record type 5, 19, 24 is made up by 20 6-bit characters (120 bit). Some AIS transponders pad the name with highest bit on in eache 6-bit byte, some don't. I also filter the @'s im my receiving station. For details of AIS records see i.e.: https://gpsd.gitlab.io/gpsd/AIVDM.html

Brian Silverstein

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Jul 22, 2024, 4:10:46 PMJul 22
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We have the same problem on the APRS.fi iOS app. I live near the water and the map is unreadable with @@@@@@@ everywhere. I have to set the Map Filter for AIS ships to “But not these.”  

I hope it’s possible to filter out the @@@@@ in the software. 

Thanks and 73
Brian K7BLS

Klaus Lohmann

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Jul 24, 2024, 5:32:16 AMJul 24
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Heikki, just in case you want to filter the @'s: replacing the motorboat icons whith sailboats when applicable would be nice.
Thank you for all the work you do.
Klaus
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