Cruisers Forum

Join CruisersForum Today

  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
Thread Tools Search this Thread Rate Thread Display Modes
Old 26-07-2012, 11:31   #1
Registered User
ngermain's Avatar

Join Date: Mar 2012
Location: Vancouver, BC, Canada
Boat: Westerly Jouster 21
Posts: 30
Images: 2
AIS position reports but (almost) no Static reports?

I got a bit of a mystery with AIS static data here, not sure if this is common? Someone has run into this before?

I installed an AIS Class B transceiver on a boat that's in a marina 200m from where I work. It has a ~6' whip antenna and 2 spliced co-ax cables connecting it, I soldered the connections myself, for better or for worse. 20 minutes after powering it up, I get position reports from about 50 vessels but static reports (ship name etc.) from about 3-5 vessels. I'm missing a huge amount of static reports. At work, a few hundred meters away, our AIS receiver picks up about 100 vessels, all with static data too.

I was thinking maybe because I was in a marina surrounded by radio obstacles that maybe the position reports were coming through because they were smaller, single-packet messages and less prone to inerfereance destroying them. The static data messages come in multiple packets so maybe there's a higher chance of one of them getting corrupted. I took the boat out into the middle of the commercial harbour, within 2 miles of at least 50 vessels with AIS. Again, 20 minutes later, very few vessel names appearing.

But what's weird is I can pick up AIS position reports from ferries 18 miles away but no names from tankers 200 yards away.

So I thought maybe something was crazy with my DIY co-ax splices so I took a 2nd antenna out there with an off-the-shelf cable. Same thing.

What's going on? Has anybody had this happen?

Thanks for any tips or insight!
ngermain is offline   Reply With Quote
Old 26-07-2012, 18:31   #2
Registered User

Join Date: Apr 2007
Posts: 718
Re: AIS position reports but (almost) no Static reports?

You may just need to wait a little longer. Static data is xmitted every 6 minutes. With that many vessels near you, it may take a while for the packets to get thru.

fairbank56 is offline   Reply With Quote
Old 26-07-2012, 19:07   #3
Registered User

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 18,290
Re: AIS position reports but (almost) no Static reports?

It may also be overload. I have seen receivers that got overcrowded and then they selected the data based on proximity.

BTW ask the manufacturer, perhaps there is/will be a software update that will sort out your issue.

barnakiel is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Advertise Here

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:34.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.