AIS Receive Problem Identification

[dlochner]

This might help. It is from Marine Traffic.

What kind of information is AIS-transmitted?

A functioning AIS transponder keeps transmitting information even when the subject vessel is anchored. The information contained in each AIS-data packet (or message) can be divided into the followi...

help.marinetraffic.com

What kind of information is AIS-transmitted?

@dlochner is correct. Not all data is transmitted all the time.

Thanks John.

A fun thing to do with AIS and Marine Traffic is to put your boat into a fleet and set alerts for your boat. Then when you get to port you'll get an email saying you have arrived, in case you needed to know that.

 

[jssailem]

Yep...

 

[Brian D]

@Rick D, it was the WRONG beer, I tell ya, geeze!

Good job and thanks for the detailed update on the issue. The NanoVHA will come in handy when you get it. Play with it and get used to loading different firmware. The firmware I am using is specific for antenna analysis and provides larger font. You will also need some SMA to SO239 adapters or pigtail cables. I think you will enjoy having the NanoVNA in your tool box.

 

[Richard19068]

@dlochner is correct. Not all data is transmitted all the time.

Correct but, from the linked information: "Static & Voyage related Information (such information is provided by the subject vessel's crew and is transmitted every 6 minutes regardless of the vessel's movement status)" . I've lately tracked class A vessels for much longer than 6 minutes without their names coming up.

 

[jssailem]

It happens Richard, that some vessels do not transmit their names relying on the MMSI to identify the vessel.

Static & Voyage related Information (such information is provided by the subject vessel's crew and is transmitted every 6 minutes regardless of the vessel's movement status).

 

[Richard19068]

It happens Richard, that some vessels do not transmit their names relying on the MMSI to identify the vessel.

Static & Voyage related Information (such information is provided by the subject vessel's crew and is transmitted every 6 minutes regardless of the vessel's movement status).

Thanks John. I get it. What's different is it seems that many fewer are now providing the name. I miss that. It seems like a step backwards. To hail a vessel by their MMSI or lat lon position is a bit cumbersome.

 

[jssailem]

I agree Richard. Having the opportunity to contact a boat/ship by name is a great way to make direct contact. It has worked for me several times both calling out and on the receiving end. When someone starts a call on channel 16 with my boats name my ears perk up immediately. It promotes safe boating

I have also been frustrated when I have tried to contact a boat, used the ship to ship channel, called the boat by name, tried DSC call to their MMSI, called the boat on guard channel 16 to discover their intention all to no avail. Finally forced to tack in order to avoid a collision.

Some times the systems just do not work as expected.