Mr. Legault, on your web site, you have a photo of Vega you use to illustrate another point. I believe it is a photo of Vega, even though it is a poor quality image of Vega. In the same way, Mr. Vandebergh's photo is a photo of USA-129-KH. It has distortion, as does your photo of Vega. If you concluded that Vega is shaped like Soyuz, you would meet some resistance, but you didn't; and Mr. Vandebergh isn't making particular claims about his photos either. He took a photo of a difficult subject, and published it for our benefit. Why complain about that? Paul -----Original Message----- From: seesat-l-bounces+paulgrace=lookoutranch.com@satobs.org [mailto:seesat-l-bounces+paulgrace=lookoutranch.com@satobs.org] On Behalf Of Thierry Legault Sent: Tuesday, May 10, 2011 13:49 To: SeeSat-L@satobs.org Subject: Re: USA-129-KH perigee pass 09/10 high-res image hi all, there are two problems with this image. First, we have no reference image or data that would give us just an idea of the real orientation of the satellite at that moment and how its silhouette would appear, therefore we have no information at all that would help us to check if the image corresponds to any reality. Second, the raw image (the small dot in the center of the frame) shows all the signs of distortions due to turbulence or telescope shaking on a point (or a very small) source, and/or noise, as I have illustrated on this page: http://legault.perso.sfr.fr/bad_astrophotography.html Atmospheric and instrumental artefacts on one hand, and the absence of data about the real silhouette of the satellite and the other hand, gives all degrees of freedom to find, within the thousands images of a video sequence, a lot of them that may evoke a satellite, above all if it’s enlarged 400% (four times) as here. But all serious imagers know that, to have a minimum of confidence in "details" shown by images of very small objects, especially 8-bit compressed color images taken with a bottom-of-the-range camcorder such as the one used here (JVC GR-DX27E), in any case one raw image cannot be sufficient. Many raw images (dozens at minimum) must be combined and they must show consistent details. The animation shown above is far from sufficient, since it contains only two consecutive frames, separated only by 0.04 sec, so that the turbulence may well be correlated. In short, in the absence of such a consistent series of raw images, in all likelihood the contents of this image correspond to nothing real. regards At 18:06 06/05/2011, Ralf Vandebergh wrote: >subject: USA-129-KH perigee pass 09/10 high-res >image >______________________________________________ >First result (long promised) of one of the >favorable perigee passes of USA-129 over the >past time. Shown is raw frame and processing. >Don’t need to mention; Hubble-shape is >recognizable! >http://freeimagehosting.nl/pics/283c3320907a92e30d483bcf4d4584f1.jpg >Best regards, Ralf Vandebergh ------- Thierry Legault www.astrophoto.fr _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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