To overcome this, an Intel Edison's processing and connectivity capabilities was made use of. Since a prototype setup like this (working around 137MHz) demands good elevation and an unobstructed view of the sky, it is not feasible to have a processing station right where the antenna is located. This signal data which has a very high sampling rate and every element of data received from it is critical for that satellite pass period.
Set up audio piping wxtoimg software#
The reception of APT Satellite Signal data (to be explained in a short while) was accomplished by leveraging the power of Software Defined Radios.
I'll try it running under Wine on my Linux box after I knock a couple of "Honey Dews" out tonight. I dug out my Hamtronics R139, and as soon as I "resurrect" it (where'd I put that darn wall wart?), I'm going to see how well it works with this M2 RB-144 eggbeater.Īnd it turns out my old "WXsat" program will NOT run on Windoze 7, regardless of the compatibility mode selected. I just downloaded the older program I used to use " WXsat", and I'm going to give it a try, too.Īnd it looks like I might be cutting some PVC pipe this weekend to make another turnstile antenna. I've done this before, with a Hamtronics R-139 receiver, a receiver specifically designed to receive APT transmissions, and it worked quite well with a homebrew turnstile antenna. From listening to recorded APT signals at various places around The Web, mine sound at least as clean, and I'm pretty sure they should decode. I'm going to take all the files I've recorded so far and run them through "xwxapt" on my Linux machine and see if I have any better luck.
Quite a bit easier to determine what filter bandwidth to use when the display isn't crammed together so much! If I hadn't adjusted the bandwidth of the RTL unit for that particular pass, the display would have been about three times as crowded!ĪNYWAY.today's experiment was to see if the FCD makes it easier to tune in the NOAA satellites (it does, although SDR# will let you adjust the bandwidth of the RTL unit), and to make an attempt to determine what a good filter bandwidth would be.Ĥ0 kHz looks about right, and that falls in line with all the things I've read about what filter bandwidth works best for receiving the NOAA APT satellites.Īs far as using WXtoImg to decode the received signals.well, still no joy. If you look at the bottom pane of the display you'll see the "tracks" of the signal, and looking at the upper pane, you see the grey area corresponding to the receiver filter bandwidth, in this case about 50kHz: The screenshot below shows the received spectrum of NOAA-18 earlier today. Doing this cuts out any strong signals that might degrade the desired signal, and it's always worthwhile doing if you can. The first thing I noticed was that it was very easy to set the filter bandwidth to include *only* the signal from the satellite.
I only had a couple of passes of the NOAA birds, so the only software I tried was SDR#. The software I use with the RTL will allow you change the sample rate, which cuts down on the amount of spectrum it decodes, but I didn't see any difference in doing that. The FCD has a much narrower bandwidth, about 80kHz, than the RTL dongle. SO.When I got home tonight I decided to see if my FCD ("FUNCube Dongle) would work any better that the $20 RTL dongle I have.
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