RE: sputnik image solved!

From: Ted Molczan (
Date: Mon Oct 17 2011 - 06:02:11 UTC

  • Next message: Peter Wakelin: "SATOBS 2011 October 17"

    George Roberts wrote:
    > After 4 hours work I finally found where that sputnik image is within the
    > sky.  I owe most of the credit to  Here is a link to the
    > part of the image I used for the solve:
    Congratulations George!
    Earlier today, we both independently decided to give up on that poor reproduction of the Uppsala Schmidt image, but at
    heart we are not quitters, and while George was trying yet again, so was I, and I too finally got a solution:
    > Here is a shot of google maps with and without the photo superimposed on the
    > star field.
    > It was hard to get it to scale and rotate and fit just right.  Something is
    > distorted - probably the film or the reproduction process to get the image
    > onto the magazine.  The image turns out to be about 2 degrees the long axis
    > (not 4 degrees as predicted).  Also the image is not mirror image but as one
    > would see it looking at the sky.  North is down and to the left (you can see
    > a N on a compass circle in upper right corner of pictures).
    > If you switch quickly between the above 2 images you can see that all the
    > stars line up.
    That is excellent. Makes clear how difficult this field is to ID, despite prior knowledge of the general location.
    For my solution, I used a more refined version of the approach I tried a couple days ago. I extracted a small portion
    that is somewhat clearer than most of the image, but this time I provide a more realistic estimate of the image size,
    and narrowed the radius of the search. That resulted in an almost immediate solution.
    > The path is extremely close to where Ted predicted it.  Just
    > eyeing it I'd say the path is 0.05 degree to the right of Ted's prediction
    > (but maybe I'm in the wrong epoch).  Still I had a heck of a time matching
    > up this rich milky way region of the sky.
    > As soon as the jiggling ends the path goes over a star at (according to
    > google earth):
    > 13h 42m 34.4s  dec -65 15' 15"
    > I don't know how to tell if it is epoch 2000 or some other epoch.  Anyone
    > know how to use google earth?
    I'll have to look into that. I extracted four positions spanning 1.1 deg of arc, and ~6 s of time. The cross-track
    residuals relative my best preliminary TLEs (derived several years ago) are within a few hundredths of a degree of arc.
    These new positions are more precise than most of the ones used to produce those elements, so the residuals are more a
    measure of the accuracy of the TLE than the new data.
    Greg Roberts and I have been conducting a similar exercise on a 1957 Nov 1 photo that he located, that was taken from
    what was then the Union Observatory in Johannesburg. The star field was identified on Sunday, and the image has yielded
    several excellent positions that will help constrain the orbit analysis.
    Once the analysis is complete, I intend to publish the resulting TLEs, as well as details of the data and analysis, and
    any interesting findings.s
    Ted Molczan
    > - George Roberts
    > -----Original Message-----
    > From: Ted Molczan
    > Subject: RE: Seeking information from Spaceflight, Vol 1, No. 6, Jan 1958
    > [...]
    > SAO Special Report 10 (March 1958), reported an observation from Mt. Stromlo
    > on 1957 Oct 08 at 09:37:31 UTC, at RA
    > 13:36:54, DEC -64:53. Epoch not reported. That position is close in time and
    > track to several of my best preliminary
    > solutions for the orbit of the rocket. The photo should be in the vicinity.
    > [...]
    > This preliminary TLE of the rocket should be within ~0.1 of track, and
    > perhaps 5-10 s time:
    > 1 70000U          57285.40716306  .00497834  00000-0  19181-2 0    01
    > 2 70000  65.2501 317.6994 0482128  46.6160 317.4072 15.03056479    09
    > Ted
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