Hi Tido, and Thanks!
I am impressed what you have done.
I didn't know that you can receive with a coax-cable I thought this is good for insulation and not for receiving a signal.
Yeah but basically the coax braid and conductor are tied together in the two loops, so it is basically acting as a single conductor. I just used coax cable because it was the hardest cable I had to make the loops. I will do another antenna with a copper pipe ^^
I saw on the picture you also used an USB device.
It would be nice if you list what kind of parts /plugs and software you are using, like a BOM (bill of material).
Yeah its a RTL-SDR Device. It's basically a DVB-T Dongle that have a RTL2832U chipset. You can search for RTLSDR in Amazon, Dealextreme and other places that you will find a compatbile device. Also would be good if LeMaker can do a dongle like that, since its cheap (or maybe even embed on a ARM Base board ).
I have used both SDR# (Windows) and GQRX (Linux) to record the baseband and audio. And on windows you can use WXtoIMG to decode the APT Audio Signal.
I'm also doing a project called Open Satellite Project, that is a receiver station and server bundle that automatically tracks the satellites and record the signals when they are in range. After that it decodes an generates the image and uploads to a server. My idea is to have a global-wide stations all spread and generate the most realtime possible stitching of the globe - The project is hosted on github: https://github.com/racerxdl/open-satellite-project
Another thought that striked me, what if a lightning hits the antenna?
Yeah this can be really bad. Not in my case to be honest. The neighborhood have a lot of anti-lighting towers and also I do have in my roof. After I finish the coding and making it work on LeMaker Guitar, I will post a schematic of lighting filter. But for now if anyone is concerned about lighting, you can use a normal antenna protection for that since all cables (and the antenna) is 75 Ohm and works on a compatible frequency of TV Receivers.
The picture with the mapping and cloud, does it come like this from the satellite?
With the cloud, yes. The borders from countries / state dont. Also the image is black & white. That image is a output of WXtoIMG (I'm planning to do on my project as well with fully opensource code), but basically the satellite sends two channels, one with Near Infrared Image and another with Thermal Infrared. With these two images you can compose a fake color image (like the one I had on my article), also you can use these two informations to see what is ocean, what is vegetation, what is burning, etc...
About the borders from countries / states, the WXtoIMG put a overlay over it because it knows where the satellite was (because of the time sync), I'm planning to do this as well on my project.
And not just humans even cats show some interest
Yeah, they really do xD
After I finish getting the station to work with Guitar Board, I will make a tutorial how to make it work