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Communicating Via Space Dust
klieber writes: "Never mind IP over Avian Carriers, here's a company that really sends data over space dust. Transfer rates are up to 20Kbps but because the data is transferred in short, sporadic bursts, the usable transfer rate is more like 9600bps. (And it uses a proprietary protocol, not IP) The technology, called "Meteor Burst," has been around since the 1930's and was apparently first developed for the U.S. Military. It's now being targeted at vehicle positioning systems and is being used by a private ambulance company in the Pacific Northwest." This is ... really strange.
just tune any quality FM reciever to a dead area(no signal and quiet) at the lowest freq. you can; and listen close. you might hear something like this.
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for an explanation of whats going on and a link to NASA's radio meteor detection system at Marshall Space Flight Center go here: http://www.spaceweather.com/glossary/forwardscatt
- "Hear that?! The percolations are imminent! Cease your ingress!"
In principle you could use a 50bps (or even slower) signal to do GPS work, but in practice it would be too hard and expensive to nail down bit transitions accurately enough and would make initialization *very* slow. Enough so that it would be a silly thing to do.
But a couple megahertz of BW isn't bad for what GPS can do, when you think about it... but it really is a lot more than 50bps.
I hearby submit a replacement sales pitch :
Probably need a lot less technical support in the world if all companies used sales pitches like that.
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
this technology is nither new nor strange.
I have been involved in a testing run with this technology a few years back.
We set ut a 'server' that constantly transmits an idle signal. when a station recives this idle signal it establishes an 2 way comunication with the server on 2 frequencies. The link lasts for only a very short time.
Messages between stations are always sent via the 'server' making it possible to reatch half the continent with one server.
It's not so easy to eavsdrop on this system, you can easily find the idle signal, but unless you'r located very near one of the comunication stations you won't be able to eavsdrop on the databursts. This happens becouse the ionized atmosphere only creates a very limited footprint (area where you can hear the other station)
we devised our own simple protocols for the testing. We did not use IP becouse you have very short time to transmit, and in that time you need to do handshaking and conduct as much datatransfer as possible.
My experience is that the system is very stable, reliable and secure. Pity you can't get very high transferrates.
SEP
Yummy! Also, Rice Krispies came bundled with strawberry flavoured exploding 'space dust' last year. Scrum-diddily-umptious!
Does my bum look big in this?
In principle you could use a 50bps (or even slower) signal to do GPS work, but in practice it would be too hard and expensive to nail down bit transitions accurately enough
In the early 1960's, scientists at The Johns Hopkins Applied Physics Lab in beautiful Laurel, Maryland, determined the orbit of Sputnik from listening to the doppler shift of the radio signal as it passed. APL's chairman came up with the neat concept that if you knew the orbit of the satellite, you could determine the position of the receiver from the doppler shift as well.
This was the birth of TRANSIT, the first satellite based navigation system. It transmitted orbit ephemeris every 2 minutes, and the receivers used the doppler shift curve to figure out location.
TRANSIT also had satellites called "Oscar" long before OSCAR (i.e. Orbiting Satellites Carrying Amateur Radio), which lead to many confusing conversations when I first worked at Johns Hopkins APL.
Obviously, there is way too much VC money out there.
Someone you trust is one of us.
Also, "Soft hit = binary" should have a zero after it. Don't know what happened there...
My karma's bigger than yours!
SIG: HUP
The reflecting surface lasts a few seconds. Because it's not suitable for voice, hams usually use very high speed Morse code, much faster than you could send by hand, sent by computer and read off a video display. Two way communications work this way: one party sends their message repeatedly over one minute on the odd minutes, the other party sends on the even minutes. The odds are that during that minute there's a meteor where you want one and the message gets through.
Thanks
Bruce
Bruce Perens.
Yes, this is an old trick. Whenever there's a meteor shower (a few days of increased activity, when Earth passes near the residue of a comet; this happens a few times a year on schedule) a lot of ham operators point their VHF (2 meter or 70 cm CW, typically) antennas at it and bounce signals off of the tails. Not exactly the meat of long conversations, but a nice way to get some well-beyond-the-horizon contacts into the logbook (think "radiosport"; we do it for the challenge, often competitively).
I suppose if you throw enough at it, you can find enough tiny meteors to make it a fairly regular means of communications. But it's rarely the medium of choice, what with dirt-cheap geostationary satellite bandwidth for the sites that can't get to the fiber networks.
If the antennas are pointed up at space, and if they are directional enough, they can use the same spectrum as other ground-to-ground systems and not interfere.
This will make more money than Ginger in five years.
Well, not really. Back in the olden days when I was a lad, long before commsats and optical fibers, we used to use High Frequency radio for long-distance communications. The signals bounce off of the ionosphere. Meteor Burst is essentially the same thing, except that you're waiting for that momentary ionization trail created by a descending meteor to bounce the signal. I worked on a military project that was using MB. The trail lasts a brief time and is random, but there are so many meteors hitting the atmosphere in a day, that it was seldom more than a few minutes before we got an open path to burst our data. The challenge was, we were doing this at the dawn of the microprocessor age and it was quite the software triumph to set up our little beacon/burster program in 2048 bytes.
"If I have seen further than other men, it is by stepping on their glasses." - Michael Swaine
"Comrad, lets hold off untill the kids go to sleep"
eather way, theres always iridim
Broadband Pr0n for all!
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Does anyone actually have a Java program designed to control air traffic, or for the operation of a nuclear facility?
Magic dust man! Magic dust! (please don't mod this up---i'm kapped out. go play whack-a-troll instead.)
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Am I the only one who thinks Microsoft is a misnomer? Perhaps Macrosoft would be a better fit?
To make the dust layer reflection more reliable, there was in the 1960's a military program to put needles (well, dipoles) in low Earth orbit to form an artificial reflecting layer. I forget the name, but it was run by MIT Lincoln Labs. After a huge controversy (about polluting outer space!), it flew and... nothing happened. Not enough needles, I guess.
Of course, this was at a time when they were (in Project Starfish) exploding nukes 600 km up to see what it would do to the ionosphere...
I wasn't aware that DGPS was capable of getting down into the cm positioning accuracy area. Is that cm range achieved by using DGPS in conjunction with carrier tracking? I led an engineering team that did some early work on DGPS for NASA and the Army back in the '80s for precision approaches and we didn't see accuracies like that using straight differential (but it was good enough to meet CAT II requirements when you used P-code). Carrier tracking was pretty much out of the question at the time (cost = outrageous). Having been out of the GPS field for a number of years now, I have to ask: Is carrier tracking common in today's receivers?
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I've seen a lot of people say "why would you do this if you can get really cheap satellite bandwidth". Well, because this method uses FREE bandwidth.
It's a niche application certainly, but there is a place for this technology. Rural areas, mountainous areas that can't get LOS to the geosynchronous ring, etc.
In fact, here's an article that talks about an ambulance company that is using the technology right now. (The article mentions a further niche use for their technology as a sort of Lojack system.)
Gentoo Linux http://gentoo.org/
While Meteor Scatter is an interesting mode, I think that Airplane Scanner is even more interesting. Recently Hams have been bouncing Signals in the 10Ghz range off the metal skins of high flying Aircraft. Communication ranges of up to 500 miles have been recorded. A recent (last few months) article in QST had the details...
I talked to these people two years ago, and they had a functinal system, mostly used to communicate with trucks in unknown odd territoria, such as Russia. The guy also told me they had lots and lots of interference from the NATO bombing on Serbia Paul
You noticed that,too? I used to run across at least an article every couple of months in the IEEE Transaction on Communications back when I was in college (which was too long ago for me to want to mention just now). While doing research I would run across similar articles in the journals that predated the IEEE. This is old stuff indeed.
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Not susceptible to unauthorized listeners? Huh?! It's just standard broadcast.
The rest of the page talks about a mixed-mode (line-of-sight + meteor burst) operation. I bet they never implement the meteor burst aspect: it's just a hook for customers and investors. Ordinary phone technology would do as well or better.
What interesting things, besides positioning, can be done with low bit-rate channels?
-- Stanislav Shalunov
I would imagine that the significance of their technology is that they've found a way to make it sufficiently reliable. Of course, I wouldn't be completely surprised if they're just whoring for VC/stock by trying to make 70 year old tech look new. From the look of things, it's probably a mix of the two. They're probably avoiding using IP in part because it assumes a generally reliable connection. On the other hand, the word "proprietary" makes VCs drool because it implies a functional monopoly and/or patent royalties. Not to be confused with "standards-compliant" which apparently implies "making money off of someone else's R&D". Thanks to the spin doctors we'll never know, but if it means cheaper long-range communication, I'm all for it.
WARNING: there is a trojan on your
This is ... really strange.
Meteor scatter isn't that strange, since the space dust ionizes the atmosphere. Moonbounce on the other hand is ... really strange.
In moonbounce you use the moon as a passive reflector. Google has more info.
RFC1925
(DUCK)
OK, OK, but it was pretty lame to begin with. The only advantage of this thing is its operability without satellites, and if anything happens that would wipe out all the satellites (hint, it would probably involve lots and lots of uncontrolled nuclear fission and fusion reactions) would probably also wipe out MB propagation too. I think.
OTOH if it didn't wipe out MB comms it would almost certainly have the opposite effect of making them redundant by creating a huge ionospheric mirror so that all VHF comms would propagate. Hard to say, given the test history, which way it would go. It's a bit late and I'm a bit too drunk to look it up.
Either way, this silly system is redundant.
Brackets contain world's first nanosig, highly magnified:[.]
"Hey Bob! Lets bounce radio waves off space dust burning up in the atmosphere!"
[alien #1] Hey, someone on this planet is trying to talk to us with VHF radio waves.
[alien #2] Maybe they want to help us.
[alien #1] In fact they are trying to communicate with our dust tail?!??!
Soft hit = binary
Of course, everything in nature is basically analog, so hard and soft hits have to be defined in analog terms just like bits in computers - but if it really hurts it's a 1.
My karma's bigger than yours!
SIG: HUP
significantly on the news that they will be offering an additional service at the the begining of March.
This new service will be called "Mir Burst". A spokesman for the company said that while meteor burst gives only milliseconds to send data packets, it's expected that the burning trail of the russian space station Mir will give them as much as an half of an hour of reliable highspeed data capability.
When asked about the temporary nature of Mir Burst, the spokesperson said that they were in negotiations with other satellite companies to move obsolete communications equipment into lower earth orbit so that they too could re-enter the atmosphere and provide fleet communications.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"