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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!"
I'm there.
"Sorry, too late." [ducks]
shut up
you mean "SP"? YOU FAIL IT!
It starts out, "ALL YOUR BA--"
I'll finish up translating the rest tomorrow.
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
This is nothing more than a recording of a McDonald's drive-through speaker.
Man $100 for 24 hrs of work? Is that even minimum wage?
- Moomin
http://www.rathergood.com/moon_song/
"I think that overall I spent about 24 hours total sitting at my '486." With my Intel Pentium II processor, with the power to make the internet come alive, i should be able to complete the problem in one tenth the time of your 486! and since this is multimedia, my MMX processor should really speed things up!
"This should send the guys at SETI on a wild goose chase."
I would be interested in the motivation behind the challange, its clearly not a 'how good are your ear' challange as the first winner used a computer. Does he hope to boost some obscure area of signal processing or just hand out $100 just for the fun of it?
On a gamer forum, mentioning a '486 would get you laughed out in about ten seconds.
;)
On a non-technical forum, mentioning a '486 would get a bunch of (the digital equivalents of) blank stares.
On SlashDot, only a couple of people think it's anything out of the ordinary...
It would seem that the Internet has a wide variety of computing cultures
Honey, I shrunk the Cygwin
So your time is worth approximately $4.17 an hour I take it ;-)
;-)
Very cool link though - sounds like a fun challenge.
Damn though, somehow I think if I end up doing this my time will come out being worth about $0.05 an hour... all for the fun of it
-Colin
50 SWM, seeking 30-40 SWF for laughs and good times. Please contact me at XXX-XXX-XXXX.
I can clearly hear the morse code beeps. With some head phones (if I knew morse code) - I could decode this using only the world's most powerful real-time signal processing and pattern recognition device - the human brain.
-josh
"Eat at Joes" or something equilly monumental
Rus
Cheap UK and US VPS
Maybe someone could come up with a novel solution...
Turn the volume up - a lot.
Everything in the world is controlled by a small, evil group to which, unfortunately, no one you know belongs.
$100 for 24 hours == 4.16/hr. I think Walmart pays their stock boys more for the time they put in. ;)
It's TCP/IP over Morse code.
Talk about lag...
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.
Why, you've given it all away! I can tell that since you mentioned traditional signal processing techniques that the answer is clearly not in the neural network in front of you but being that you know that I know you're a Sicilian you obviously wouldn't put it in a simple band pass filter in front of me! Aha ha...Aha ha ha *clunk*
Next time, tease yourself with it. Wait until you're busting, then let it out a little and then pull it back in. Do this until you jsut can't hold it anymore, then have the best dump of your life!
Gee, I decoded parts of it... "CQ CQ CQ ... de ..."
*GRIN*
"Stop! Your radio waves are killing our moon babies! First it was Country Music, and now this."
Table-ized A.I.
Hey Suid - you made Slashdot!
Have you compiled your kernel today??
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.
You spent 24 hours trying to win $100?
Dude, you could make more than that working at Wendy's.
- A.P.
"Remember when the U.S. had a drug problem, and then we declared a War On Drugs, and now you can't buy drugs anymore?"
No, I could hear the signal from the very beginning of the wav file. Very faint, but it was there.
-josh
This is nothing more than a recording of a McDonald's drive-through speaker.
It is the repetion in the message that allows humans to know what they are really saying. Thus, we hear, "Vu Vu Von Vie Vih Vah", and know from prior experience that they are saying, "Do you want fries with that?" Otherwise, I often would not know what the hell they are saying.
Table-ized A.I.
... to drink your Ovaltine.
Portable versions of Firefox, GIMP, LibreOffice, etc
Be sure to drink your Ovaltine. Ovaltine? A crummy commercial?
no, it's the third post. YOU FAIL IT. put taco's dick back in your mouth and stfu.
Somebody mod this up as funny.
This is one small signal for man, one giant signal for mankind.
Special Relativity: The person in the other queue thinks yours is moving faster.
Reminds me of story somebody told me once, but I have yet to verify it.
During preparations for the Apollo moon missions, some members of NASA were sent out to record greetings messages from various communities to be included on a recording that was to be left on the moon by the astronauts.
After visiting a Native American tribe, one Native American man refused to tell NASA what he had just said into the recorder in his native tongue. So, they eventually found a translator, and the message said something like, "Watch out for these guys. They will take your land too. Explorers, my ass".
Table-ized A.I.
So, I've eliminated the background interference and now I have this funny sound (almost musical) going up and down (and repeting itself like the autor of the web-page said), and now I'm suposed to tell what this means?
:)
... where I live 4.5 $ / hour is a relativly good wage !
I thought morse code was small and long beeps ALL in the same frequency (all in the same note), is this some kind of advanced morse code?
For the record
I'd assume the beeps are a single tone. Run a fourier xform on the signal and look for any dominant tones (peaks) in the spectrum. Once the frequency is known, run the signal through a narrow band filter at that frequency to eliminate the noise. After that the tones should be recognizable enough to decode by ear.
Vote for Pedro
1. Enter "Slashdot Solve the Morse Code Contest"
2. ???
3. Prof.... What $100?... Never mind.
"And this little piggy went wee, wee, wee all the way home!"
Maybe not all of the morse code is that faint, but if you actually read the point of it all, the call sign is harder to distinguish.
Some of my client's outsourced my contracts to India.... hmmm $4.50 /hr and i'm charging $65/hr. And when i turn the keys over for all (355) the servers i admin.... i hope the shit literally hits the fan... especially in the accountants offices?.. they get what they deserve??bastages
(On a lighter note i hope when the shit hits the fan all they can use to access those fine Citrix servers i built is bongo drum's)
You solved this? Are you a geek or something?! Get out of here, Michael!
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.
YHBT. YHL. HAND.
Resistance is futile
This is a test. This is a test of the emergency sig system. This has been only a test.
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.
Can someone please open-source the solution (probably after winning the reward). I'd also like to see the original author's solution -- matlab code, and whatever.
Thx!
Maybe someone could come up with a novel solution and win $100!
Sounds like the best solution could just be a Gaussian filter could be passed over all the values to lessen the noise, then have the remaining values leveled on a linear scale - then finally have the translated solution passed through a common acronym/spell checker.
-Gwala
#!/bin/csh cat $0
"Drink more Ovaltine"
I took a professional signal analysis software package and analyzed the file in detail. There is indeed a signal, quite discernible, at about 570 Hz. However the package that I have is visual only, it is not suitable for audio playback, and I am too lazy to add audio output to it... not worth of $100 for sure. Also, the signal drifts considerably.
From af9y.com:
"The mystery station is one of the calls in this list of all known 2 mtr EME stations: all2eme.txt (18 K Bytes)"
peter@df5jt $ wget http://www.webcom.com/~af9y/all2eme.txt
peter@df5jt $ cat all2eme.txt|grep -i df5jt
DF5JT
peter@df5jt $
Where's my 100 bucks?
google is your friend. First came across this technology in the 1970's in a paper from the Naval Post Grad School. The problem them was how to communicate with submerged subs using only very low frequency keyed CW. google will lead you to more modern applications, e.g., "A technique for removing noise and emphasizing coherent events from multiple channels of seismic data."
Matlab is overkill for this kind of job.
A combination of Waves Xnoise, Q10 with high/low pass filters, and a peak at about 600hz, followed by C1 brings it out quite clearly.
If you work in audio production like I do, you deal with worse recorded tracks every day.
"Please send help! Drowning! Will not last much longer!"
Outdoor digital photography, mostly in New Engl
Why bother translating it? Getting all technical is the best way to ruin perfectly good music.
"So long and thanks for all the fish."
"In Soviet Russia, moon bounces YOU!"
I bet the answer is 47 - it's always bloody 47..
--A Million-in-one chance will work out 99% of the time...
This sig is in Spanish when you're not looking....
All these moons are yours
except Luna
Attempt no landing there
I had a nice morse code response here, but the slashdot lameness filter won't let me post it. Talk about lame. "Reason: Please use fewer 'junk' characters." I'll readily admit that ASCII graffiti is junk, but morse code? C'mon! ;)
http://tinyurl.com/4ny52
i downloaded the "zip" file and ran mplayer on it... it's BITTERSWEET by FUEL... WTF
What is slashdot?
It's STENDEC (or ETA LATE).
"And a voice was screaming: 'Holy Jesus! What are these goddamn animals?'" - HST
Whats the difference between this and a spectrogram? An easy one line command in octave or matlab.
Well, that's great if you're a fucking bat, because that's about what you would have to be to hear that.
I have pretty good hearing. I hear all sorts of shit that most other people I know can't, and I couldn't copy that signal in raw form if my life depended on it, and I'm somewhat practiced with morse code.
Yeah, it's there. That's known. Clear? Hardly.
"Be sure to drink your Ovaltine?"
I call bullcrap.
You listening to 3 seconds of it instaltly make you an expert?
In fact I'll bet you $200.00 that the worlds best morse code expert cannot copy the whole message from "just listening to it" because it needs some significant signal processing and tricks to get the full message out of the noise.
Listen to it again, this time the WHOLE file...
there must be some certain-frequency signal in the "noise" that occurs in the noise for two durations: the duration of a morse dit and dah. Wouldn't an FFT and analysis of the relative amplitudes and durations suggest what the message is (to a person knowing morse code)?
So, why do people use LabView for this?
detecting and decoding are two very different things.
**I call bullcrap. You listening to 3 seconds of it instaltly make you an expert ** Well, he's right. I also can clearly hear the dots and beeps in that file, with nothing more than turning up the treble amp on a pair of laptop speakers. Three other "witnesses" in the room with me at the time can also hear it just fine. And yes, we listened to the whole thing. Doesnt sound like a very long message. Since I've got better things to do with my time than jot it all down and translate it, I'll leave it to someone who actually has to work to earn the $100, not someone who can hear it. PS. You know those "unhearable, ultrasonic" pest repeller things? I know 5 people, inluding myself, who can hear those damn things ticking :p
*There's Klingons on the starboard bow, scrape em off Jim!*
Put the file into XMMS or Winamp, depending if your in linux or windows. Turn on the AMP/Equalizer, and drag everything except 12-14k down to nothing. Play, turn up speakers, unplug ears and listen. You'll hearn a pattern starting out with what sounds to ..-...-.-
It goes by way to fast for me to pick up much more than that. But I suppose I could get less lazy and slow it down.
*There's Klingons on the starboard bow, scrape em off Jim!*
Took the wave file, loaded it onto a windows pc. Loaded Nero wave editor. Select All. Analize Noise, Remove Noise, adjust equalizer... Clear, perfect morse code file... All in 15 seconds work... Sad, isnt it?
*There's Klingons on the starboard bow, scrape em off Jim!*
I was indeed able to pull out a legible signal using Cool Edit 2000, I don't speak morse. I sent the file to the folks at the center.
I will post any results to my journal.
If I win anything it is going to the EFF. (Protecting grannies from the RIAA. 24/7)
Arnold is looking pretty good right now.
Anyone want to recommend what programs to use to change my levels so i can decipher static from morse?
Anyone want to recommend a program so i can adjust my audio levels to hear past the static so i can decipher the damn morse?
With grammar and spelling like that, I'd outsource you too.
Q. How do you fix a broken chimp?
A. With a monkeywrench.
Got it!!!!
WKRP
"The avalanche has already started. It's too late for the pebbles to vote." - Kosh
Ever heard of something called 'fun'?
How about 'a challenge'?
Climbing mountains just because they're there can be rewarding, you know.
we like tha moon
cos it is close to us
we like tha moon!!!!!
but not as much as a spoon
cos thats more use for eating soup
and a fork isn't very useful for that
unless it has got many vegetables
and then you might be better off with a
chop-stick
unlike tha moon
it is up in the sky
it's up there very high
but not as high as maybe
dirigibles and zeppelins
or lightbulbs
and maybe clouds
and puffins also i think maybe
they go quite high too
maybe not as high as tha moon
cos the moon is very high
we like tha moon
tha moon is very useful everyone
everybody like tha moon
because it lights up the sky at night
and it lovely
and it make the tide go and we like it
but not as much as cheese
we really like cheese we like zeppelins
we really like them
and we like kelp and we like moose
and we like deer and we like marmots
and we like all the fluffy animals
we really like tha moon
... if I had the time:
Bretthorst-style Bayesian periodic signal detection with a sliding window to pull out individual dots/dashes. Adaption of the Gregory-Loredo pulsar detection algorithm for Gaussian noise would be better. If you wanted to build a serious dedicated program, you could incorporate more prior knowledge about the structure of the signal (e.g. that it's composed of single-frequency dots and dashes of specific probable duration, and you could even tell it to look specifically for only codes appearing in the list of station call signs).
You mean that signal spike in SETI@HOME was just an ovalten commerical...I thought it was ET phoning home....
"The problem with socialism is eventually you run out of other people's money" - Thatcher.
"Hey /. I found this Differential Equations take-home final that has been BOUNCED OFF THE MOON and I'll give $100 to the first person that completes it! Should only take about 24hrs, and I think it would be great to generate some interest in this."
my karma will be here long after I'm gone
how come noone has posted the answer yet? I would have thought for sure that someone would have figured this out by now. I mean is it really harder than everyone is saying? I've seen nothing but posts saying how everyone can hear the code straight out, but not even a partial translation yet. I figure that at least someone must around here must do this kind of thing for a living and have dirrect and quick access to something that can just give them the result... so post the answer already :)
the morse code for normal humans, use Convert::Morse from search.cpan.org...
My dad ran crypto for the Navy back in the 50's, was even given a citation from the Pentagon for his ability to pick out weak Morse Code on the fly..and decode the stuff, realtime, in his head! Spent like 6 years up in Adak, Alaska listening to Russian freighter traffic. Three cheers for Cold War paranoia!
:)
I'll pass this along to him.
Bowie J. Poag
Man,
The solution is called matched filter...
If you need to ask is because youre not going to understand anyway...
how long until
Here's what I got so far:
"We're whalers on the moon,
we carry our harpoons..."
It's easy: subtract white noise and there you go :-)
I'd assume the beeps are a single tone. Run a fourier xform on the signal and look for any dominant tones (peaks) in the spectrum. Once the frequency is known, run the signal through a narrow band filter at that frequency to eliminate the noise.
The frequency of the signal may change during transmission, due to Doppler effect. In this sample it constantly increases. So running a Fourier transform on the signal won't show you any distinct peaks.