question about telescopic arrays

[vladius]

Okay, as you probably have guessed, i dont have a degree in optics and im not an astro physicist. So here is another question for some of you more knowlegeble types:<br /><br />The power, versatility and range of radio telescopes are determined by their size. An array of radio telescopes can work as one as if it were one huge telescope detecting EM radiation from billions of light years away. Optical telescopes can detect visible EM from billions of ly away, but are limited by the size of the lense and mirror. So: why wouldnt a hundred hubble size telescopes each working inependently, but jointly aligned and in a tight cluster not have the same effect, in essence creating an apature a hundred times more powerful than a single hubble? <br /><br />Anyone?? <br />or is this a dumb question all together?<br /><br />does anyone know if this would work?? 11 views no answers yet... maybe i should go find a physics prof.

 

[alkalin]

A rather good question, actually. Since I’m not a specialist in this area, I can only give general answers. There are compositsets that can be constructed from an array of ‘collectors’. And there is a formidable amount of software to reconstruct the ‘image;’ from some antennae array. If it is done right, a ‘picture’ will be recreated that is consistent with the ‘larger’ aperture.<br /><br />Adaptive Optics is a close associate to these processes and is growing in this arena and is gradually proving these things can work. It just takes time to prove the methods and get them to work.<br />

 

[Saiph]

It hinges on the technique called interferometry. You take two signals, and merge them together, causing them to interfere. By knowing all the distances, and other variables you can then understand enough about how they intefere to pull out a composite signal.<br /><br />The problem is a matter of scale. How much room for error you have, depends on the wavelength of light you use. When using radio telescopes to monitor signals in the micron range (.001 inches) you have a "lot" of room. It isn't hard to precision build optical systems over large distances to such a scale.<br /><br />Visible light, however, requires nanometer precision, a million fold increase.<br /><br />The only reason we don't do it, is cause it's a pain in the but to build it.<br /><br />For more info, look up, "Optical Interferometry" the Keck telescopes are trying it out if you want to see what they're up to. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[odysseus145]

There are plans for a space based interferometer.<br /><br />Link<br /><br />Proposed Launch: 2009<br />Purpose: Space-based optical interferometer to study stars and detect extra-solar planets<br /><br />The Space Interferometry Mission (SIM) is an orbiting interferometer that will link a pair of telescopes to function in unison as a much larger "virtual telescope." One goal is to detect planets of varying sizes -- from huge planets several times the size of Jupiter down to planets about as massive as Earth. It will do this by precisely locating nearby stars and looking for signs of any wobble in their positions, which may indicate that gravity from orbiting planets is tugging at them.<br /><br />In addition, the mission will determine positions and distances to stars with an accuracy several hundred times greater than current technology allows. SIM will open the era of "precision astrophysics." It will permit the construction of a "street map" to our Milky Way galaxy which could lead to breakthrough discoveries in astronomy. The mission will determine the distances to important signposts throughout the Milky Way as well as the motions of nearby galaxies and it can study the activity deep in the cores of external galaxies. All of this will help us expand our understanding of the universe.<br /><br />Partnering with JPL are Northrup Grumman Space Technology and Lockheed Martin, as well as numerous institutions represented on the science teams. <div class="Discussion_UserSignature"> </div>

 

[glutomoto]

Re: An array of 'optical' telescopes<br /><br />The Keck Telescopes use Adaptive Optics and Interferometry.<br /><br />W. M. Keck Observatory - Two Telescopes, One Vision.<br /><br />I guess that two isn't a very large array, but it is a start.<br /><br /><img src="/images/icons/smile.gif" /><br /> <div class="Discussion_UserSignature"> </div>

 

[vladius]

Thanks for the answers, guys. i had no idea that keck was 2 telescopes. i knew about the crazy mirror setup, but didnt know there was 2. i imagine cost is a factor for not building a 3rd and 4th and on and on.

 

[vogon13]

Not sure what time frame if any before this might be possible, but, just go ahead and build very rigid and by neccessity, misaligned, array. Computer map misalignment and use image processing to correct pix. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[vladius]

welll, my good friend is a mechanical engineer. with my $ and his skills, and of course a donation of 1000 exactly identical telescopes, as well as a software engineer to build the program that compiles the images.... hmmm <br /><br />hehe

 

[vladius]

i did some websearches... <br />http://www.geocities.com/CapeCanaveral/2309/page1.html<br /><br />i guess optical inferometry is an old.. very old.. idea.. not in practice too much today cause its practice is still in its infancy.<br /><br />lots of info on that site on optical arrays and optical inferometry.

 

[Saiph]

another complicating factor with visible interferometry is the presence of air in the system. Variations in the air density (via sound, temperature gradients, etc, etc) will cause an ever changing variation that will foil attempts to merely map misalignments. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>