STEREO

From: Greg Roberts (grr@telkomsa.net)
Date: Thu Oct 26 2006 - 06:08:01 EDT

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     Good morning - though at the moment I feel like a bear that has
     had its hibernation disturbed- feeling very fuzzy.
    
     Despite cloudy weather I was able to observe something - at the
     moment Im not sure if it was the STEREO spacecraft or the rocket.
    
     The predictions from HORIZON are a little confusing  - they are
     still using the initial lift-off time/parameters etc and it seems the
     rocket was leading the spacecraft -which seems wrong to me.
     For example:
    
     Time(i)               STEREO                  rocket 
    Time(c)
     (UT)                az            el                az           el
     01h08m     14.3210   26.0319     16.0443   26.2817      01h22m
     01h09m     23.7649   30.2793     25.5813   30.3765      01h23m
     01h10m     32.8417   33.3048     34.6769   33.2402      01h24m
    
     Time(i) above is uncorrected time- ie have to add 14m because
    launched 14 minutes into the window. Done =  (Time(c)).
    
     If Im thinking (!) correctly then the rocket was leading STEREO
    by about less than 2 degrees.
    
     Due to cloud I started tracking blindly on the predictions for
    STEREO and managed to see "something" several times.
    
     Here are three positions Ive measured so far
    
     Time  UT            RA                Dec                  az          el
     01h21m39.3   05h46m59.8s  +30d05'07"   12.969   24.690
     01h21m42.4   05h48m45.0s  +29d44'15"   13.461   24.947
     01h21m59.2   05h58m21.8s  +27d49'58"   16.238   26.286
    
     From this I conclude that I was tracking the rocket. At the last
    position I was already tracking on the object so was operating
    at maximum "sensitivity" and the field of view started at
    azimuth 13.76 deg and covered 24.0 to 28.2 degrees so should
    have included STEREO at about az 14.32 el 26.03 deg. Looking
    at this location in the image I see nothing  so either Ive done
    something wrong or the STEREO satellites were fainter than
    about 10th magnitude. The object tracked was about mag +8.5
    and varying slowly in brightness.
    
     I have still to do more measuring but my conclusion is that
    I saw the rocket but not the STEREO satellites.
    
    The latest is that tracking data from Canberra and Madrid
    show that all is well and as planned.
    
    (quote from my "on the scene reporter" :-))
    
    >> considering where the spacecraft have been recently. Now the orbit
    >> estimates are nailed to the wall, as we say, and we're done for the
    >> night. Back tomorrow for the L+24 hr solutions!
    
    
    Cheers
    Greg 
    
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