FONER%OZ.AI.MIT.EDU@XX.LCS.MIT.EDU ("Leonard N. Foner") (02/05/86)
If my understanding of PCM's and such is correct, this won't work. One of the assumptions made in using PCM's is that roundtrip transit time is very short---short enough that the medium can't really change its properties in between the original (distorting) trip and the reflected (antidistorting) trip. While the atmospheric transit time is very short, the transit time to anything you would be looking at is not. (If the transit time is on the order of seconds or less, you can assume the atmosphere is static. But there's very little that is that close that we need better looks at... maybe high-definition telephoto lenses for watching Shuttle launches?) More to the point, though, where's the PCM? Clearly not at the object, since that's what you want to observe. If you put the mirror on the ground and put your imager at the top of the atmosphere, then you have an undistorted path between the PCM and the imager---but why not then just look UP from your imager at the top of the atmosphere? I can't think of anywhere you'd put the mirror and imager so that you could use a PCM for astronomy. Maybe someone else who's more clever can come up with a workable scheme. <LNF>