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!"

Partial translation

[aardvarkjoe]

It starts out, "ALL YOUR BA--"

I'll finish up translating the rest tomorrow.

Re:Partial translation

[Tablizer]

It starts out, "ALL YOUR BA--"....I'll finish up translating the rest tomorrow.

The complete message is: "ALL YOUR BAD JOKES GET YOU MODDED DOWN".

Re:Partial translation

[Dorothy 86]

I, for one, welcome our new bad joke overlords.

You do? Well then....

[gantrep]

Q. How do you fix a broken chimp?
A. With a monkeywrench.

Re:Partial translation

[kurosawdust]

"Be...sure...to...drink...your....Ovaltine?!?"

Cripes! It's a crummy commercial!

The joke's on you, Gary.

[xenoweeno]

This is nothing more than a recording of a McDonald's drive-through speaker.

"Do you want fries with that?"

[Tablizer]

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.

Contract rate

[Anonymous Coward]

Man $100 for 24 hrs of work? Is that even minimum wage?

- Moomin

Re:Contract rate

[anthony_dipierro]

No, but if he sells the solution to someone for $50 more it will be.

Re:Contract rate

[CausticWindow]

actually, in the us that's not half bad.

I bet some hungry code monkeys will rush to the challenge

we don't have no stinking communist unions over here you know

$100??!!

[Anonymous Coward]

sorry, i don't work that cheaply.

Re:$100??!!

[Anonymous Coward]

No - but I bet your sister does ....

Re:$100??!!

[nyseal]

I thought all Linux geeks work for free

Re:$100??!!

[terminal.dk]

$100 for 24 hours on a 486.

Let us assume it is a 66MHz machine. Let us also assume your machine today is a slow 2GHz model. Then 2000/66 = 30. So your machine is 30x faster.

24 hours / 30 = 0.8 hours. $100 / 0.8 hours = $125/hours. This is probably OK for some unemployed geek, and is way over my hourly salary working as an employee.

I like the moon

[fsandford]

http://www.rathergood.com/moon_song/ [rathergood.com]

Re:I like the moon

[code_echelon]

That was truly mind bending. I don't know where that came from but its pretty funny.

Re:I like the moon

[ryanw]

Now, dude, you weren't supposed to post the link to the answer of the encrypted message.

Re:I like the moon

[ross.w]

To think I actually installed the flashplayer on Mozilla so I could see this.

Re:I like the moon

[KingAdrock]

Spase Peepole [sparklet.com] inhabit the moon.

Easy money

[calcifer]

"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!

Re:Easy money

[gantrep]

WTF are you talking about? MMX is an Intel buzzword.

Code Broke

[CherniyVolk]

"This should send the guys at SETI on a wild goose chase."

Re:Code Broke

[c_oflynn]

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).

motivation?

[mlush]

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?

Re:motivation?

[mlush]

Well, there's one guy who set the competition, and there's one guy who won it, and is telling is.
And then there's you.

Is this another compertition to extract meaning from obscure data???

Interesting that he mentioned the '486 :)

[JessLeah]

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 ;)

Re:Interesting that he mentioned the '486 :)

[BiggerIsBetter]

I'm not sure about "out of the ordinary". It just made me wonder how long ago he did it...

Re:Interesting that he mentioned the '486 :)

[JeffTL]

I still have my= 486, KVMed with my Pentium III.

Re:Interesting that he mentioned the '486 :)

[tomakaan]

Yeah. He'd only get the blank stares if he mentioned he was using Windows ;)

Re:Interesting that he mentioned the '486 :)

[Josh Booth]

...and hysterically laughed at if he mentioned that he was using XP.

Re:Interesting that he mentioned the '486 :)

[Creepy Crawler]

I know why he used that as his example. Who actually uses, by default, a 486? Everybody in technology has something more powerful. Een a GBA has more CPU power.

Also, a lot of HAM's who're in digital transmissions use around a 486. Plenty of serials, paralells, ISA for handmade cards, PCI for those 10BT + 10B2 + AUI combo networking cards all in something you wouldnt mind if a wee too much signal went through it ;-)

Re:Interesting that he mentioned the '486 :)

[AchmedHabib]

For some reason, I still find it funny to pull out my Pentium 75mhz motherboard with 64mb ram, place it on a phonebook on the livinroom table, put a network card, vga card and a 512mb HD and then install FreeBSD. hmm

Re:Interesting that he mentioned the '486 :)

[don.g]

Bah! Try using an XT motherboard in a similar state because you want to read some EPROMs and it has a spare socket for them :-)

Re:Interesting that he mentioned the '486 :)

[harrkev]

Bah.

Real geeks use a 5v power supply, a breadboard, a handful of resistors, a couple of DIP switches, and a handul of LEDs.

Don't forget the manual for hand-disassembly.

Re:Interesting that he mentioned the '486 :)

[Jeff DeMaagd]

The top article says a few years ago, they didn't say how long ago, it could have been ten years ago for all we know.

Re:Interesting that he mentioned the '486 :)

[wideBlueSkies]

I have my old 486 right here on my desktop. It's a paperweight.

Not the box, but the CPU itself. The box went to the old COMPAQ home about 11 months ago.

wbs.

Time Worth...

[c_oflynn]

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

Re:Time Worth...

[ryanw]

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 ;-)

Well, thats still more then something like counterstrike or equiv can offer. Pay $40 for the game, play for hundreds of hours, and get nothing back in return except for a few broken mice, carpal tunnel, blood shot eyes, etc.

Re:Time Worth...

[revmoo]

Well, thats still more then something like counterstrike or equiv can offer. Pay $40 for the game, play for hundreds of hours, and get nothing back in return except for a few broken mice, carpal tunnel, blood shot eyes, etc.

And what, is the negatiev affects?

Re:Time Worth...

[Breakfast Pants]

How much did you get paid to write that post? I guess your (and my) time is worth $0.00.

Translated Message

[Herkum01]

50 SWM, seeking 30-40 SWF for laughs and good times. Please contact me at XXX-XXX-XXXX.

Re:Translated Message

[yroJJory]

The number you omitted was:

877-779-3974

This number courtesy of Dave Barry and the Direct Marketing Association.

Re:Translated Message

[petecarlson]

877-779-3974

were sory, you have reached a number that has been disconnected.

Guess the SWM 50 had to change his number because SWFs wouldn't stop calling him...

Note to self: Look into bouncing number off the moon...

Re:Translated Message

[harrkev]

Note to self: Look into bouncing number off the moon...

Hams can do this no problem. It is called EME (earth-moon-earth). All it takes is some patience, a HUGE antenna with a pair of rotators, a back yard, and being willing to withstand the icy stares (and death threats) of your neighbors for putting an antenna like that up.

Who needs Matlab? I can hear the morse code beeps

[joshv]

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

Re:Who needs Matlab? I can hear the morse code bee

[c_oflynn]

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.

Re:Who needs Matlab? I can hear the morse code bee

[joshv]

No, I could hear the signal from the very beginning of the wav file. Very faint, but it was there.

-josh

Re:Who needs Matlab? I can hear the morse code bee

[Daniel_Staal]

Here: Morse Code [google.com] 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.

Re:Who needs Matlab? I can hear the morse code bee

[edwinolson]

detecting and decoding are two very different things.

Re:Who needs Matlab? I can hear the morse code bee

[Ceadda]

**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 so

I'm sure it will say

[rf0]

"Eat at Joes" or something equilly monumental

Rus

Re:I'm sure it will say

[ScottSpeaks!]

"Watson come here, I want you."

How to deal with weak signals:

[WegianWarrior]

Maybe someone could come up with a novel solution...

Turn the volume up - a lot.

In the spirit of a recent story:

[bersl2]

It's TCP/IP over Morse code.

Talk about lag...

Re:In the spirit of a recent story:

[BiggerIsBetter]

Or maybe it's Morse code over bongo drums?

From the Moon. Talk about loud...

Re:In the spirit of a recent story:

[phre4k]

Yeah short is a hit on the drum. Long is.... A loooong hit on the drum

Not given it away?

[Anonymous Coward]

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*

It says....

[Tablizer]

"Stop! Your radio waves are killing our moon babies! First it was Country Music, and now this."

Suid is showing off!

[stevew]

Hey Suid - you made Slashdot!

WTF?

[Wakko Warner]

You spent 24 hours trying to win $100?

Dude, you could make more than that working at Wendy's.

- A.P.

Re:WTF?

[yarbo]

he said it's $100 for the next person to solve it, it's possible first (or whatever) place got a larger prize.

Re:WTF?

[Felinoid]

No I couldn't

Me:[monotone] "Welcome to Wendys may I take your order."
Costummer: "I want a pizza with everything and a big mac"
Me[Shooting costummer]: "Next"

Re:WTF?

[The Cydonian]

A friend of mine works as a management trainee at JP Morgan. We once calculated:- she'd be earning more at the local 24 hour McD's if she worked the same number of hours she puts in at JP Morgan. Think about it.

Re:WTF?

[telstar]

"Dude, you could make more than that working at Wendy's."

• Last week, the woman working the register at the Wendy's I went to was named Wendy... ya think she thinks she owns the joint?

Re:WTF?

[theonetruekeebler]

Perhaps this prize's symbolic nature would be clearer if instead of $100 is was a pair of rusty pliers.

Don't forget...

[CritterNYC]

... to drink your Ovaltine.

I got it...

[anthony_dipierro]

Be sure to drink your Ovaltine. Ovaltine? A crummy commercial?

Hrmph

[Lozzer]

This is one small signal for man, one giant signal for mankind.

moon messages

[Tablizer]

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".

Re:moon messages

[plone]

False [snopes.com]. 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.

Re:moon messages

[dvdeug]

Seriously man, is it really necessary to spread such bullshit urban myths when 2 seconds at Snopes shows that it is fake?

Why not? He didn't present it as truth, and it's a cool story, true or not.

Re:moon messages

[FPCat]

When I was in school, the last thing I would have done is ruin a good sirloin steak with Coke. However, I would dissolve it with beer (in my stomach!)

Re:moon messages

[stevesliva]

He forgot to mention he used "Coke with active bacterial cultures" and "white castle sirloins."

*I* thought it was a tooth that Coke dissolved. mmmm... coke.

Re:moon messages

[aceat64]

Oh, sorry about that, I ate the steak...

Re:moon messages

[danila]

BTW, did you know that When the Titanic hit an iceberg in the north Atlantic, the silent version of the film The Poseidon Adventure was being screened aboard ship. [snopes.com]

What I would do.

[geekee]

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.

Code is solved

[bigjnsa500]

Solved and translated by my transmografier:

Resistance is futile

Reminds me...

[gbooker]

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).

Open-source the solution!

[Schnake]

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!

Novel Solution

[Gwala]

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

I kinda see the signal

[tftp]

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.

WTF?

[DF5JT]

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?

Re:WTF?

[po_boy]

While you're at it, collect your useless use of cat award [mooo.com].

Coherent detection

[artch]

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."

Re:Coherent detection

[Detritus]

Can you use coherent detection if all you have is the output of the demod?

I got it!

[MongooseCN]

"Please send help! Drowning! Will not last much longer!"

Don't Analyze It, Just G R O O V E to it

[BlackBolt]

Why bother translating it? Getting all technical is the best way to ruin perfectly good [wired.com] music [slashdot.org].

Re:Don't Analyze It, Just G R O O V E to it

[BlackBolt]

Which reminds me, I've started my own contest with the white noise from my tv set after closing time. Anyone who can guess what channel I was watching wins.. uh.. uh.. something really good.

hint: people were naked.

So long, and thanks for all the fsshhh

[juglugs]

I bet the answer is 47 - it's always bloody 47..

--A Million-in-one chance will work out 99% of the time...

Something's going to happen...

[One Louder]

All these moons are yours
except Luna
Attempt no landing there

Re:Something's going to happen...

[LouisZepher]

Well, I guess we're fucked then, eh? Better watch out for giant domino-wannabes plummeting from the sky...

i downloaded the zip

[wmaker]

i downloaded the "zip" file and ran mplayer on it... it's BITTERSWEET by FUEL... WTF

I got it!

[pherris]

It's STENDEC [pbs.org] (or ETA LATE).

Assume that

[Rock Ridge]

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?

A tip to hear with just ears.

[Ceadda]

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.

Hmmmmm.. .Wheres my dad?

[Bowie J. Poag]

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. :)

Re:Money well earned.

[fantastic]

Try writing a book, if you don't get a best seller you would probably earn even less

Re:Money well earned.

[kfg]

Yeah, but Wal-Mart doesn't let you stock shelves in your underwear while eating Doritos and chugging Mountain Dew.

No, I don't want to talk about it.

KFG

Re:Why no morse code posts on slashdot?

[Sparr0]

use letters instead of . and -, maybe i and t (see the dot and dash along the middle of the row?)

Re:Solved

[coolmacdude]

I used the same thing. However I didn't get a clear sequence of morse. It was more of a constant tone interrupted by breaks. I couldn't make out any detailed signals that would be letters.