Plasma Antenna Astronomy

[orrery]

Are there any Radio Astronomy observatories that have begun using Plasma Antennas? If not, why not? If so, how is their performance compared with traditional antenna systems and what kind of advances can we expect with plasma antennas applied to Radio Astronomy?

[orrery]

http://www.amazon.com/Plasma-Antenna-Ex ... 3844305300

Editorial Reviews
Product Description
Recently, there has been a revival of interest in plasma antennas because of their potential advantage over the conventional antennas. Hence experiments are aimed at investigating the antenna properties of a reconfigurable plasma antenna. Plasma column is excited by surface wave, which acts as a plasma antenna. Antenna parameters of plasma antenna and equivalent metallic copper antenna are studied. By changing the operating parameters a single plasma antenna (plasma column) can be transformed into multiple antenna elements (striations), which can be treated as a phased array broadside vertical plasma antenna. In addition, physical and antenna properties of reconfigurable plasma antenna can be controlled by operating parameters. Moreover wireless communication capability of this plasma antenna is tested. Striations have always been a subject of academic interest to scientists. Therefore, the studies of striations in surface wave produced plasmas has been extensively done both from experimental as well as theoretical points of view. This book invokes applications of pattern formation or striations of plasmas in plasma antenna technology.
About the Author
He did M.Sc. from B.H.U Varanasi, and Ph.D from Institute for Plasma Research (I.P.R), India. He was a postdoctoral researcher at LAPLACE, CNRS, Toulouse, France. Currently he is a postdoctoral fellow at I.P.R, India. His areas of interest are plasma, striations, surface waves, plasma antennas, wave-plasma interactions, microwave photonics etc.

[The Great Dog]

Prototype plasma antenna.

[Jarvamundo]

Where did you dig that up dog?

[jjohnson]

I doubt it. This sounds more like a potential military application (radar) in the testing or experimental phase, since (in the article's abstract) they invoke stealth and worry about radiating plasma noise, usually not a problem with a passive antenna in a non-hostile environment.

The bandwidth looks like it's in an appropriate region, too, but they are designing active radiators/receivers, whereas a telescope has no reason to radiate unless it is trying to "light up" a target - hardly likely outside our solar system, and generally impractical beyond the few closer planets and moons since everything else is so far away, and it's hard to have sufficient gain to light up something the size of even Jupiter at that distance, and not waste a lot of energy. Arecibo can light up the Moon or Venus, and that's about it. It illuminates the occasional asteroid, too, but the resolution is so poor that it is best used for doppler estimates of rotation rates and orbital parameter estimates, not surface imagery.

The interesting thing about signal reception in telescopy (?) is that you want to get as high a signal-to-noise ratio as possible, just to detect a signal that has been spreading for thousands to billions of years. With small optical telescopes, the greater the aperture, the more photons/s can be directed, properly focused, onto the detector. With larger telescopes, greater effective aperture can be obtained by spacing the scopes out in long baseline arrays, and using such aperture synthesis and Very Long Baseline Interferometry to mathematically reconstruct the signal and create images.

Currently in radio astronomy we use the Earth's diameter to get as wide a (real-time) terrestrial baseline as practical, although several European and U.S. and Australian radio telescope systems utilize smaller baselines very effectively, too. (For geometrical parallax to measure distances across space, where time is not crucial as it is in interferometry, we use the diameter of Earth's orbit as a baseline.) In the future there are plans to station orbiting telescopes a much wider distance apart and use micro-thrusters to maintain their distance apart as constant as possible during an observation. In radio telescopes, size matters, both dish aperture and baseline.

Jim

[jjohnson]

Jarvo -

http://msnbcmedia1.msn.com/j/msnbc/Comp ... id-4x2.jpg
is the image URL (I just right-clicked the picture ). Looks like a story off msnbc - you may have to play with it a little to locate the actual article.

Wait, that doesn't work; this does:
http://www.msnbc.msn.com/id/22113395/ns ... -material/

Note the 2008 date mentioned for prototype completion and testing. Not too current, and nothing much since. My guess on military apps was right.
Jim

[Jarvamundo]

cool..nice one...

still thought the gag was good tho... dog, dig etc.. ahwell... "shut up dad".

Yeah i'm with ya on military applications... It'd be hard to jam an antenna that doesn't exist.

[Osmosis]

Good for making microwave hash!

[hertz]

the analogy that comes to my mind regarding a plasma antenna is that of using a magnifying glass to start a fire...perhaps it's all about focus...harold aspden claimed tesla had plans to use such an antenna to power a car, but alas the plans have never surfaced...simple way to pinch the aether?

[orrery]

I am considering whether or not I should drop a Benjamin on this book here:
http://www.amazon.com/Plasma-Antennas-A ... 997&sr=8-1



Has anyone read it?