Weather forecasts at sea

General Othernet Discussions
1

I am interested in setting up Outernet on my yacht to receive weather forecasts at sea using a RaspberryPi/SDR/L-Band patch antenna combination. A few questions:

  1. I assume the patch antenna is not weatherproof - will it work mounted either inside the boat or within a weatherproof case?
  2. If I opted for the Lantern is this also weatherproof in the marine environment?
  3. Is the motion of the boat going to be a problem receiving data from the satellite?

Phil

2

The patch antenna isnt weatherproof but if it got wet, the concern I would have, would be with the feedline and corrosion. If the antenna feedline became wet with salt and water it would begin to degrade its signal handling ability. It may be possible to insulate and protect with some rubber compound or enamel but I would expect the junction to the main feed panel to be the first thing to go…

As far as motion of the boat…the antenna needs to be pointing at the satellite. If the antenna is moving vertically but is still pointed to the satellite you should not have an issue.

You may want to opt for the CHIP option instead of the Pi as new development is happening on this platform.

3

Thank you Jherman. Already have a Pi 2 so was hoping to start with that.

4

Phil I’m working on a stabilised platform for a yacht application. That won’t be too difficult but the power consumption of the CHIP, SDR, LNA kit is a concern. My unit draws well over 2A - as much as my fridge!!

I believe that the Wi-Fi middle us a big culprit and wonder whether a scheme can be implemented whereby it is only enabled periodically.

I’m traveling at the moment but when I get home in January I’ll look into the power consumption question and finish the platform. I’d be happy to send you the design files once it’s complete if you’re interested.

5

I would also be interested in a stabilized antenna platform.

I am not 100% sure it would be needed in the tropics as the satellite is almost directly above. I use to have a Worldspace L-Band Satellite streaming Radio. I mounted the patch antenna, flat up next to my solar panels and it never stopped working.

But I concede for music a small interference to transmission is barely noticeable but with Data it may be a lot more of a problem.

One option could be a hemispherical high gain antenna possibly a Helical similar to the ones sold by Inmarsat.

Healing underway could be a problem though.

I looked into 12 volt / 5 volt 10,000 RPM hard drives providing gyroscopic stabilization. It is a technique very commonly used by the DIY Handicam stabilization crowd.

Let me know of your success’s.

Seasalt

6

I am looking at modifying this Helical Furuno GPS antenna if any one has any ideas.

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