Fw: What software did you use for the ISS transit download?

From: Tom Wagner (sciteach@mchsi.com)
Date: Sun May 11 2003 - 16:21:55 EDT

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    I hope you all don't mind but I am forwarding an e-mail from one of the guys
    that video-taped the ISS/Mercury solar transit recently. It is interesting
    and some of you may want to communicate with him as well.
    Tom  Iowa  USA
    ----- Original Message ----- 
    From: "Alfons Gabel" <alfons.gabel@t-online.de>
    To: "Tom Wagner" <sciteach@mchsi.com>
    Sent: Sunday, May 11, 2003 5:34 AM
    Subject: Re: What software did you use for the ISS transit download?
    Dear Tom,
    last night I wrote the whole story to a mail group. Maybe you are interested
    in it, too?
    Dear observers of the hole in the Sun called Mercury,
    during the Mercury transit the area of Mainz/Germany lay inside a narrow
    path, where the International Space Station passed in front of the sun.
    On May 7 at 05:18:48 UT, 2.8 minutes after Mercury's second contact, the ISS
    entered the sun's disk just a few arcsecs east of Mercury, and hurried
    across within 4 seconds. Several observers noticed this event visually, some
    describe the shape as elongated or triangular, about as large as Mercury or
    somewhat larger.
    But obviously me and my son Alexander are the only lucky people who captured
    it on video, also photos are not known yet. Maybe the publication will
    incite further observers to review their recordings.
    Because of the larger field of view, I decided to use my old-fashioned VHS
    camera attached to my Celestron 8 plus focus reductor. But this caused the
    problem to gain a good digitized and compressed copy. Best thanks to Ulrich
    Rieth, another member of our local astronomy club "Astronomische
    Arbeitsgemeinschaft Mainz", for his decisive support!
    Because we are still working on an improved version, it wasn't my intension
    to publish the preliminary one right now. But Ulrich sent a short sequence
    to http://www.spaceweather.com/ ... and please have a look, where it came
    Now it happened!
    You can find another short sequence, including a slow motion on
    http://www.astro-mainz.de or directly to article (in German) and videos via
    If you cannot recognize the ISS at the first time, have another look. It
    enters just left of Mercury close to the upper solar rim, and rushes
    downwards within 1.4 seconds. The increasing video quality during the
    following hours showed, that the limit at this time was not conditioned by
    the technics, but mainly by the poor seeing at this early time, and barely
    12 degrees above the horizon.
    By the way, if the airplane which exactly crossed the sun shortly after the
    ISS transit, would have started from Frankfurt airport more than 74 seconds
    earlier, it or its following disturbances would have destroyed the event.
    Traffic jam in front of the sun!
    What was the ISS's orientation? As far as I know yet, we saw the ISS modules
    nearly nose-on, and the solar panels face-on at maximum span. Face-on? No,
    they should face the sun, therefore we should have seen exactly their back!
    Torsten Schaefer used the programs Giotto and Registax to stack and process
    35 frames showing the ISS. I further processed his result trying to suppress
    the video line artefacts. A rough estimate shows, that the ISS shape should
    not be elongated by more than 10% due to its motion.
    I feel somewhat audacious, but nevertheless I attach this preliminary
    result, hoping that anybody can help to check up the orientation of the
    panels. The dark sector at top left is not beyond the solar rim, it is the
    result of the contrast enhanced gradient of the solar surface.
    Surely such analyses are amazing, but for me the most inspiring thing is the
    "all-over arrangement" of Mercury and ISS in front of the sun, at the same
    Of course, this observation was not coincidential. A few days in advance
    Gunnar Glitscher posted an alarm via http://www.meteoros.de/forum.htm
    Ulrich Rieth recalculated the track several times, based on all published
    changes of the orbital data of the ISS. His final outlook, just an hour or
    so in advance, showed that the observatory "Paul-Baumann-Sternwarte" in
    Klein-Winternheim (49d 56'47.2"N, 8d 13'33.0"E, alt. 200.0 m, WGS 84), just
    a few kilometers ssw. of Mainz, still lay within the 11 km wide path. So we
    could stay there, as scheduled. It even would have been possible to move
    slightly, in order to shift the ISS track right on Mercury, but no one
    expected that the orbital data and the calculation could be precise enough.
    But they were!
    Best regards and clear skies
    Alfons Gabel
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