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The Weak Signal Challenge - Decode and Win $100
superid writes "Several years ago while reading comp.dsp I found a link to The Weak Signal Challenge. On that page is a .wav file of a morse code signal bounced off the moon. The page author Mike Cook is offering $100 to the next person to successfully decode the morse code.
Since I was the one who originally solved this, I promised Mike that I wouldn't divulge the answer or provide any clues. I can say thought that I didn't use anything special other than traditional signal processing techniques, octave, matlab, and patience. I think that overall I spent about 24 hours total sitting at my '486.
I think it would be great to generate some interest in this. Maybe someone could come up with a novel solution and win $100!"
BTW, on the page it DOES mention that the code is a call-sign, so for people suggesting that its some odd thing ("Eat at Joe's", etc)... RTFA (unless its slashdotted).
Umm.. thats not quite the point. The page says this:
Do you think you are good at copying weak signals? Well here's a test for you. I am posting a zipped 1 minute wav file of a VERY weak EME station calling me. I am offering $100 and a free copy of the FFTDSP42 to the first person who can tell me the call sign of the calling station. The signal is strong enough to just copy my call (AF9Y) near the middle of the 1 min period. The mystery station is sending a simple repeat of his call and my call. The characters "DE" may or may not be between the two calls.
So you CAN hear one of the call-signs... its harder than just listening carefully. Otherwise it would make no sense.
Here: Morse Code info.
Now all you need is a pair of headphones. I'm sure you can find a decent pair for less than $100 and make some quick money.
Try it. I'm betting it's harder than it sounds, but hey: people's hearing does vary. You might just be good at this.
'Sensible' is a curse word.
For my senior design project, we had to make some dedicated hardware to exactly this. It was solved using an FFT inside a Vertex-II Pro FPGA using a sliding window.
Now, as far as this contest goes, this can be done quite easilly in a computer. In fact, we had made a bitwise simulation of the FPGA using matlab before doing any Verilog to make sure that our design worked. My favorite was the little setup that we did in LabView. Took about 30 minutes to make, and would solve this quite easilly. It was very nice to see the result in color intensity with frequency along the x axis, and time across the y. Seeing the data in there was quite easy even though the SNR was so low that you couldn't even hear most of the tones.
In short, if you want to do this, read the data into matlab (or octive), do an FFT on a small window of the data, slide the window over, repeat. Take all the FFT's and plot in an intenisty graph (not sure what the matlab term is, but I am sure it has such a thing).
You see? It's like I've always said. You can get more with a kind word and a 2x4 than you can with just a kind word.
False. Seriously man, is it really necessary to spread such bullshit urban myths when 2 seconds at Snopes shows that it is fake? Oh wait, I guess you must be one of those people that believes that a litre of Coke will dissolve a steak in 2 days.