RTL-SDR + OpenCPN on a mac

[kabazz]

Hi,

I'm trying to use a usb rtl-sdr as an AIS receiver. I've downloaded opencpn and the mac RTL_SDR plugin, but I'm stuck on how to get it working as there is no manual? Is some other software needed?

Alternatively a windows guide might help, as i might be able to borrow a pc, but mac would be ideal

Thanks

[AISFan]

Rtl_ais may be your only choice on mac. You need to compile it by yourself. If you look at other platforms, you may have more choices.

Sent from my Coolpad T1 using Cruisers Sailing Forum mobile app

[CarCode]

The time he spent to get rtl-sdr running he could better use to earn some money and to buy a real AIS receiver. They are not expensive anymore these days and work immediately.

Gerhard

[AISFan]

Which real ais receiver is the best? I cannot see many choices here. Can you provide some information?

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[CarCode]

Originally Posted by AISFan

Which real ais receiver is the best? I cannot see many choices here. Can you provide some information?

I can't say which one is the best because there are hundreds on the market and who wants to buy all of them for testing? I guess the cheapest one is about 40 bucks.
Personally I use a VHF radio with build-in AIS receiver, actually the RO4800 from Radio Ocean. This has the benefit not to need another VHF antenna or an antenna splitter which is the worst solution.
Gerhard

Here is one for 60 US$ e.g.:
https://www.tindie.com/products/astu...-ais-receiver/

[AISFan]

It is too sad that I can see only three choices here. None is under 400 dollars. No test is even seen online for them. A base station can be even more than 35,000 dollars.

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[CarCode]

Originally Posted by AISFan

It is too sad that I can see only three choices here. None is under 400 dollars. No test is even seen online for them. A base station can be even more than 35,000 dollars.

I don't know where you live but anywhere in the world Google search is available. Give it a try and see hundreds of cheap AIS receivers...

Can it happen also you don't know the difference between a class B and a class A receiver?

Gerhard

[AISFan]

That is just one reason why people uses rtlsdr. The price you see does not include local taxes. I would like to see cheap but best ais receivers being sold here on taobao.com if possible.

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[CarCode]

Originally Posted by AISFan

That is just one reason why people uses rtlsdr. The price you see does not include local taxes. I would like to see cheap but best ais receivers being sold here on taobao.com if possible.

That is chinese ********. Obviously you are a troll. Come back when you want to be serious.

Gerhard

[petter5]

Originally Posted by CarCode

That is chinese ********. Obviously you are a troll. Come back when you want to be serious.

Gerhard

I can confirm that the dAISy receiver works fine without any hassle https://www.tindie.com/products/astu...-ais-receiver/

Just US $ 59,- https://www.tindie.com/products/astu...-ais-receiver/

[bdbcat]

Folks...

I recommend dAISy for an entry level AIS receiver that just works right out-of-the-box with no fiddling.

Dave

[rgleason]

See dAISy here towards the bottom.
AIS Receiver USB dongle | Official OpenCPN Homepage

Purchase here:
https://www.tindie.com/products/astu...-ais-receiver/

[rgleason]

Adrian now has available dAISy HAT a two channel receiver for RPI

• True two channel receiver, continuously receiving on AIS channels A (161.975 MHz) and B (162.025 MHz)
• Superior sensitivity compared to other low-cost AIS receivers
• Low power consumption, less than 200mW in receive mode (<40mA at 5V)
• 38400 baud serial output in industry standard NMEA format (AIVDM)
• Communicates with Raspberry Pi via UART0 (ttyAMA0)
• Works with Raspberry Pi 1 (A+/B+ only), Pi 2, Pi 3 (see note below) and Pi Zero
• Shape and size compliant with Raspberry Pi HAT standard
• Breakout pads for 2 independent TTL serial outputs, 3.3 and 5 volt rails, and Raspberry Pi I2C port
• BNC or SO-239 pigtail to connect antenna included (antenna not included)
• Made in USA

https://www.tindie.com/products/astu...-raspberry-pi/

[bdbcat]

Rick...

Just ordered one. Will let you know how it goes.

I have been studying the interaction between simple one-channel AIS receivers and most Class B transponders, and the results are a bit concerning, if my data and observations are true.

I have been using an SDR for spectrum analysis, and a dAISY programmed for single-channel-only mode to look at some real life data.

1. I find that most (all?) single channel receivers only switch channels when they detect an error on receive, usually due to transient noise.

2. I also find that many Class B transponders transmit on only one of the authorized TX channels, most of the time. They are supposed to alternate channels for "periodic repeated" messages, but they don't all seem to do this.

Result: If I am listening on Channel 1, and your transponder is stuck on Channel 2 for a long time, I may never see you. Or it may take a very long time (multiple minutes). This problem is exacerbated by the long reporting period and subordinate network access methods of Class B transponders.

So, in short, I'm beginning to conclude that the utility of Class B for inshore work to be compromised and sometimes dangerously misleading for collision avoidance. This does not mean that the utility for offshore long-range collision avoidance is null. It just means that one should not rely exclusively on AIS-B for close-in navigation.

But we knew that already....


Food for thought...
Dave

[rgleason]

Very interesting. I supose since Adrian has a github repository for the program, we can make sure there is adequate switching in daisy products, but what about the others?
I wonder what Adrian and Robin at Vesper would say?