SETI signal

Kmguru, this would be an unusual use of the GPS system. The GPS system wouldn’t be used directly for determining antenna location. (Processing the GPS signal at the data collection site could provide extremely precise antenna location and timing.) The satellite signal is the important element. Used as a reference signal it would need to be very stable and have a complex waveform. SeekerOfTruth is likely correct that the GPS signals have those qualities. As long as the home antenna operated in the right frequency range this hamster feels that SeekerOfTruth’s system would work. (Bet some of those Hughes satellite guys are sufficiently interested in space science that they’d help.)

 

Log in or Sign up to hide all adverts.

Log in or Sign up to hide all adverts.

Kmguru, perhaps you are right. This hamster thought the GPS system had deliberately built in limits for security reasons. This hamster also guessed that the clocks on the DirectTV transponders would be insufficiently accurate for interferometry. Guesses aren’t as good as knowledge. Hehe.

Some radars use a varying frequency chirp waveform as a reference signal. By convolving the reference waveform against the return signal a highly precise distance measurement is possible. Using similar techniques to compare reference signals from multiple sources to the data from the antennae, highly precise measurements of location and time should be possible. By using the measured distortion in the reference signals one may also “clean-up” the antenna signal. In this manner it should be possible to get clean signals with precise phase information from mediocre antenna data. That should lead to good interferometry.

 

Log in or Sign up to hide all adverts.

this all sounds like a plan but what guarantee do we have that the nice folks over at directv and NASA will listen to us? They probably feed their mail to goats.

 

Imahamster,

The GPS system had a component called Selective Availability or SA that randomized the clock output of the individual satellites as well as introducing errors into the ephemeris data that was transmitted by each satellite. SA was originally intended to degrade the accuracy of commercially available GPS receivers so that foreign powers could not use GPS as a targeting aid for their own ICBMs. Unfortunately, or not depending upon how you view it, commercial enterprises were smart enough to figure out how to remove SA from the signals. This is one of the primary reasons SA was turned off last year. Without SA, you have a fairly accurate real time clock in a GPS receiver and with processing such as that used in differential GPS you can position things down to milimiter level precision. This means you have an extremely accurate clock when looked at over large baselines.

In regards to the use of Direct TV clocks for interferometry, I do not know how accurate the clock is, but knowing how accurate a GPS clock is and needs to be tells me that the Direct TV clock is not nearly as accurate.

To use the GPS system you could have essentially two designs. In one, a separate GPS antenna would be physically coupled to a radio astronomy antenna with the exact distance between the phase centers of each antennna being known in advance. The GPS antenna and receiver would provide both accurate timing and position for the astronomy antenna. If you then 'listened' to the GPS signal on the astronomy antenna, you could perform a limited set of interferometry between the GPS antenna and the astronomy antenna as well as performing interferometry between different radio astronomy antennas.

The second method would be to design a single antenna designed to look at the radio astronomy bands of interests as well as the GPS signals. This would be a little more complicated and would eliminate the possibility of doing interferometry between the GPS antenna and the astronomy antenna, but would potentially be a smaller and lighter package.

 

Yes. I saw it too on a program on Discovery. Its supposed to have happened quite a few times. But these freak cases are not really taken seriously because apparently interference etc can cause them.

- Sivakami.

 

Well one conclusion to what happened was that an armchair radio operator fired a message out onto the moon and waited for it to be reflected back at him, but with extreme luck it wound up being obsorbed by a SETI dish, and with more extreme luck wound up being exactly what they were looking for.

On an episode of Sightings (old TV show on the scifi channel) this one guy who claimed to have worked as a janitor or something said that SETI recieved five separate signals from five different species in the Orion Arm (I believe but am not sure). Of course this guy is the only evidence the Sightings blokes had and they just ran his interview and showed some shots of the sky. Needless to say this means that there was next to no proof of this except for a janitor's testimony, and there was no proof that he had even worked there.

Buttt there is always the chance that he was telling the truth, that we've made contact with species from another world. I really, really hope I live to see such an event.

 

Yes, its true, at the moment it's just as likely that there really is no other civilization out there as it is likely that the universe is peppered with them. What a sad concept.

 

Much as kmguru has mentioned, if another species or alien civilization was discovered, chances that Joe Q, Public would ever hear of it are slim or none. Military and political leaders would clamp a national security lid on it so fast that even the discovers would have spinning heads. The chances of learning something new for offense or defense of national interest would be the driving plot behind it. It well could be that our radar stealth tech was inspired by such tech. Who knows?

 

Actually Wet1, the roots of our stealth technology go back to Soviet research in the 50's and 60's.

Maybe they are the ones who received the signal.

Please Register or Log in to view the hidden image!

 

Makes sense. Occam's Razor.

- Sivakami.

 

Many groups, like the UN, have various protocols in place to handle various things. But information release is still determined by the decisions of those who actually have it. If Australia's DSD receives a signal, I doubt very much that they'll call the newspapers first.

 

I can put forwards that there is a true possibility of life else where in the universe, but to make my suspicion more tangible, you'd have to look to the ideas of Modeling the universe in a computer to recreate it.

(the understanding is if you input information from the point you start (with data you have collected) to a future point, you should have enough to Model a reverse of how things have been to get an understanding of the beginnings of the universe.

Most will note this as being what Cavendish Laboratory, Cambridge intends to accomplish.

Of course I would like to put the point forwards that those calculations would be lapse of other life forms that our own, since they (and perhaps an meteorite worm) seem to be the only evidence of ET life.

This means that a Theoretical calculation has to be derived about how much life exists in our universe to input in the model. (that way if the model has any relevance on our universe it would prove the existance of life, in fact you could even point where!)

My kind of assumption is from the big bang there was 0% life, but blocks that accumilate over years to create life (even if those blocks stayed frozen and inanimate for thousands of years), over some time you can imagine that life would spread throughout the universe from the first explosions and settle, possibly populating about 6-7% of the universe.

Over time there would be a fluctuation in growth, admittedly all life would be stuck to their planets to begin with and some might find themsleves made extinct by changes to their environment.

Life exists in 5% of the Universe, when the first evolved life starts taking to the star's, then there is a sudden (in a relative sense) growth to life populating worlds that would have been uninhabitable earlier. By this point, differing communications systems would have been developed.

Suddenly life exists in an increasing percent of the universe, the only thing that controls its growth is War, Famine, Pestilance (Oh and something us humans created.... Capitalism!)