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Old 13-10-2013, 16:16   #1
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Wx via the NOAA sats and WXtoIMG

I’m new around here but t’other day I was reading through the thread in weather information offshore Obtaining Accurate Offshore/Hi-Seas Weather data/forecasts, while at sea
and I saw that Skyeye and the NOAA sats got a bit of a mention but then the thread wandered off somewhere else.

A bit of background, I have had my boat in the ‘southern cone’ – south of Buenos Aires/Pto Montt - for just shy of 10 years. I have a ham ticket and a reasonable number of radio toys on board.

The weather options down here are fairly limited.

I have Navtex and the Chileans put out Navtex but I have never received any weather on it…. just navigation warnings. Pretty much the same with Argentina… however they do put out weather forecasts for the ‘mythical Malvinas’ several times a day but not much else.
Likewise with wefax….. the Chileans operate quite a reasonable system although it does have its moments …. On the Argentine coast …nada.
Voice is the same … the Armada de Chile puts out good stuff for the fishing boats on HF but you need reasonable Spanish.
I can get gribs via the Sailmail station in Los Lagos, Chile but gribs are gribs…. Computer generated predictions with no human input …. Amazing how many people think ‘is electronic…is good ‘ and have never read and inwardly digested the warning that sailmail sends out quite frequently.

Some six or so years ago I met up with a chap who had just finished fitting a home made (boat made?) Quadrafiliar Helix which he was using in conjunction with a $50 secondhand Bearcat/Uniden scanner.
So having done a bit of research and having tried to build my own QFH I ended up buying a turnstile Weather Satellite Station - Wettersatelliten NOAA Receiver and Antenna, WRAASE electronic GmbH - Hardware - MX-137 which is every bit as good as a QFH. This also needed a Bias-T to feed it with 12v. The next bit of kit was an Icom R-1500 which I already owned… more on radios later. To complete the system I use WXtoIMG WXtoImg: software to decode APT and WEFAX signals from weather satellites which is free… however it is worth springing for the $69.95 upgrade. That software is available for PC or Mac.

Is it worth doing? Definitely …. There are only 3 working sats at the moment but that means 6 passes a day and what you see is what is happening in real time… not a wefax analysis or a grib prediction but right now.

It takes a little time to learn how the picture relates to what is happening on the ground … heavy cloud in a frontal system often means a steady but moderate breeze while what looks like fair weather cumulus can mean violent squalls.

Back to the receivers… I have never used a Bearcat/Uniden but believe they work well. There are also dedicated receivers which I have no experience with. My R-1500 would probably be overkill for most people but works a treat.

I do have some dongles including a Funcube and a Funcube Pro + FUNcube Dongle | A radio that's out of this world! . Both work well with the satellites but are a bit fussy when it comes to tuning… apart from that they are fine.

I also have a couple of RTL dongles, go to ebay and look for ‘RTL-SDR RTL2832U R820’ .. not as good as the FCD but they do work… at only $10 they are a cheap introduction and you can us them for other stuff as well including AIS RX . There is some interesting stuff here. Software Defined Radio for Mariners

Antennas? My turnstile on the boat works just as well as the professionally made second hand QRF I have at home (99c plus $20 postage on ebay…… )
If you are really keen it is possible to build your own QRF or Turnstile .


Pics in order.... 1/ my turnstile, 2 and 3/ at sea in the mouth of the Rio de la Plata , second one is enhanced to show precipitation - black is nasty with lightning, 4/ steady winds NE of the Falklands, squalls to the SW. 5 and 6/ Hove to off Puerto Deseado in late April... SW gale with snow...oh joy oh happiness....
Frank VK3JFH/VP8DNM
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Old 13-10-2013, 16:26   #2
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Re: Wx via the NOAA sats and WXtoIMG

And also. A Funcube Dongle receiving a NOAA sat on a Dell Netbook. Not a good computer for it as there is too much latency but the FCD is doing a good job.... that was using a QFH at my home QTH.

I was feeding the signal across to a Macbook Pro... you can see the effect of the latency in the second photo.
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Old 13-10-2013, 17:39   #3
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Re: Wx via the NOAA sats and WXtoIMG

and a little note re the last two pics in my first post.... normally when lows coming across the Pacific meet the Andes they hang a right and head down towards the Beagle... you can see in those pics that a low has just jumped the Andes in the same latitude as Puerto Deseado. That led to some 'interesting times'..... you wont see that sort of stuff on a grib.
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Old 14-10-2013, 03:21   #4
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Re: Wx via the NOAA sats and WXtoIMG

Quote:
Originally Posted by El Pinguino View Post

Antennas? My turnstile on the boat works just as well as the professionally made second hand ***QRF****
I can't edit that but it should read QFH or Quadrifiliar Helix.....
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Old 15-10-2013, 18:34   #5
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Re: Wx via the NOAA sats and WXtoIMG

Oh man....I've got so much to learn. I'm using your post like a reference at this point. Thank you for the post. I'm off Panama and am refitting an old boat. I'll be needing some reasonable weather prediction gear....so I'll be doing a lot of reading.
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Old 02-02-2014, 11:42   #6
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Re: Wx via the NOAA sats and WXtoIMG

The RTL-SDR / SDR# takes a lot of computing power, but I will tinker with it too

This winter I bought a dedicated WX receiver (WRAASE APT-06). As for the antenna, I built a simple turnstile antenna, a cross-dipole with a lambda/4 delay between the dipoles, similar to this:

Der "GL-Dipol"



Despite the antenna being too close to the ground, between the houses, the received pics are great.

Dirk
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Old 11-03-2014, 06:41   #7
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Re: Wx via the NOAA sats and WXtoIMG

Quote:
Originally Posted by LeaseOnLife View Post
The RTL-SDR / SDR# takes a lot of computing power, but I will tinker with it too


Dirk
You got some nice images there, congrats.

If computing power is a problem try running SDRSharp with less eye candy, go to config and reduce to 0.5 MSPS, turn off waterfall, minimise everything unde display.
I managed to get nice images on a dual core 1.6 GHz with 1 GB ram with eye candy off, recording the output from VB cable and then processing the audio file separately.

Good luck with that, as the original post refers to my blog I'm happy, if you need help with WXSats PM me.

Cheers,

Akos
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