whipper_snapper
regular
Reged: 09/08/2006
Posts: 1439
Loc: Kenya
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You may remember a couple of weeks (?) ago Captn. Slarty posted about the NOAA satellites and suggested they may be useful to help interpret weather data.
Well, today I have been messing about with the system. Using my normal Yaesu 857 transceiver, into the soundcard of my normal beat-up old laptop, using a programme called wxtoimg to capture and process the images (and control the radio which improves the results slightly by allowing for doppler shift), I came up with the image below.
The antenna is a home-made J-match designed for 144MHz while the satellites transmits on 137MHz!
I must admit, I am quite pleased, it needed no extra kit at all, except that I paid for the upgrade to wxtoimg from the freeware version. The paid-up version can control the radio so it copes better with the narrow bandwidth of a 'normal' receiver, and changes freq to allow for automatic capture.
I have no idea what the image is telling me. My location is marked with the small red cross, and it was 6/8 cloud as the sat went over. I suppose need to fiddle around with the various false colour systems to highlight cloud which I guess is what I want to see.
Off now to build a better antenna which should improve the results dramatically.
Pointless? Possibly! But it would be very very easy to install on the typical liveaboard which will already have most of the kit needed.
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KellysEye
regular
Reged: 23/07/2006
Posts: 737
Loc: Curacao
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We don't use your system but we find infrared pictures are the most useful. The colours are cloud heights and thus indicate rain, squalls, thunderstormes.
Animated pictures are best because you can see which way the weather is moving - down here weather doesn't necessarily move with the lower winds. Particularly true with weather coming off Venezuela that is often travelling in a north east direction when the prevailing winds are from the NE/SE.
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Foxy
regular
Reged: 08/03/2006
Posts: 128
Loc: Cruising
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could be useful and certainly fun. We have an icom and pactor... what else would we need? Is it in Captain's post?
Cheers
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whipper_snapper
regular
Reged: 09/08/2006
Posts: 1439
Loc: Kenya
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At an absolute minimum, assuming your Icom can cover 137MHz FM, you don't need anything except software to decode the signals. There is lots around, I am using WXtoImg because it offers lots of very nice enhancements on the paid-up version (cost about £30) and the demo version seemed to do a better job than all the others I tried. JVCcomm can in theory do it, it has the advantage that it gets data off the Pactor, but it did not work well with the weak and dirty signals and cannot do the very clever things such as shift frequency to allow for Doppler shift.
You just connect an audio output from the radio into the sound of your PC, tune your radio to the frequency of the next satellite and wait for it to come over. WXtoImg will predict this for you. On the paid version it will tune the radio for you too.
BUT. The big but is that the results with a standard VHF aerial will always be mediocre at best. So the 1st enhancement is a better antenna. I plan to make one out of a few bits of wire and drainpipes following these instructions. I will report back.
If you want to go the whole hog, get the R2FX APT Receiver from here. That should give superb results with a decent antenna.
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