Raspberry Pi as an AIS Transponder

[monkeyx]

There seems to be quite a few tutorials about how to integrate an AIS receiver to OpenCPN with a raspberry Pi.

I am looking at how feasible it would be to use a raspbery Pi as a transponder. There are some projects that can use a pi as a radio transmitter, but it might be more feasible to upload AIS data via the https://www.aishub.net/ service.

I have seen one demo that combines IAS data, GPS and timestamps using Signal K and Node-RED which could possibly then upload via data.aishub.net, if the pi has an active connection to the internet.

Has anyone else tried something similar to this?

[sveinung]

Uploading your position and AIS information would do nothing to make boats around you see them on their AIS, it wouldn't go out on the VHF band at all, just be on their site. So unless your goal is to show someone at home/web where you are, it wouldn't do you much good.

I'm going to guess that transmission to the 87B and 88B channels are restricted to FCC approved equipment.

Granted there's nothing stopping you (it's a very simple and open protocol), but if you get it wrong you might be jamming the normal operation putting vessels at risk.

[BillKny]

Originally Posted by sveinung

I'm going to guess that transmission to the 87B and 88B channels are restricted to FCC approved equipment.

Granted there's nothing stopping you (it's a very simple and open protocol), but if you get it wrong you might be jamming the normal operation putting vessels at risk.

^^^^^ All the above is true. ^^^^^

Just as an example of the problems: Once you hook this to a radio, how exactly are you going to test it's broadcast system without screwing with the local AIS system?

AIS transceivers are now cheap enough that the only rational reason for doing this is for fun and for bragging rights. Please find another project for your entertainment.

[monkeyx]

Thanks for the update.

I had incorrectly assumed that the aishub would share information back to Marine Traffic for other ships to pick up as well.

Will look to add a dedicated AIS transponder to my boat and link it to an NMEA 2000 network so that a raspberry pi can see the data still.

[francois.lavoie]

I am also interested in the AIS transponder. I found a very cheap open source solution provided by Peter Antypas:

Here is the thread on the Maiana transceiver easily convertible to a transponder:
https://github.com/peterantypas/maiana
And here is the link to buy the fundamental 2 layer boards ($20) to do so:
https://blog.oshpark.com/2016/11/27/...s-transponder/


Any raspbery pi specialist to give a newbie protocol to build the thing?

[hoolie]

Are you going to get your device FCC approved, or your national equivalent? If not you may be at risk of prosecution for illegal radio transmissions.

[francois.lavoie]

I did not thought about this. Very pertinent observation.FCC is the american governing body, IC is the canadian equivalent.
Thanks.

[francois.lavoie]

Very pertinent observation. FCC is the american governing body, IC is the canadian equivalent.
The conceptor of maiana sells the basic modules to build the transceiver and not as a transponder, and advises the buyers accordingly. You have to build the transceiver unit yourself. Already built units are not yet available.

The conceptor is waiting for his patent to be approved as a transponder, from what I could read. CAD and firmware are licensed under GPLV3.


Thanks.

[bcn]

The patent does not take away that a radio station - an AIS transponder is one - has to be type approved by the corresponding entities in order to be legal.
One will need the corresponding document to be entitled to register and to use it.
In the Maiana blog there is some statement that the developer can set up some systems and use them without FCC approval.
First one should should check this statement carefully and second this will not help anybody else who wants to use it as a transponder.
Even if it takes only some smaller soldering to enable the transponder functionality in the Maiana AIS kits.
Nice project by the way.

[francois.lavoie]

You helped me realized that that device was not on the market. I was wrong to present it otherwise. And you are right, it has not been approved as a transponder by the goverment authorities whether they be canadian or american.

In fact, if you read closely the exchanges on the site, this device is in development. The developer is sharing is unit with the open source community. The device is not finished. It is in the spirit of the open source community to share freely ones work and accomplishment with the community so that the community provides even further evolution of the object (software or hardware).
We are far from the attitude of private companies, including Apple, Microsoft and Google (Android). Apple has built its actual OSX partly with FreeBSD which was and is still open source code.
https://developer.apple.com/library/...g/BSD/BSD.html

Microsoft after bashing Linux for years seems to look for some conversion or compatibility with Linux. Linux has a share of 50% of the servers business. The software is free.

https://www.techrepublic.com/article...r-open-source/

This said, sorry to have misled anyone on this forum.