Optical 13 Feb 2007

From: Greg Roberts (grr@telkomsa.net)
Date: Wed Feb 14 2007 - 08:16:09 EST

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    Observations 13 Feb 2007:
    ----------------------------------
    
    Cosatrak 1 (Computerised satellite Tracking System).
    MINTRON low light level CCD surveillance camera (0.005 lux typical
    in non integration mode) and 0.00005 lux in STARLIGHT mode with 128
    frame integration.
    
    Used with 6 inch f/5 Celestron,camera integrating for 128 frames
    which is equivalent to an exposure of 2.56 seconds per image.
    Telescope mounted on CoSaTrak mounting. Field of view 28.2 by
    22.5 arc minutes. Can see to approximately mag 15 in "realtime" on
    the monitor for geostationary satellites and about magnitude +14.5
    for trailed stars.
    
    Site 0433 : Longitude 18.51294 deg East, Latitude  33.94058 deg S,
    Elevation 10 metres - situated in Pinelands (Cape Town), South Africa
    
    For Classified.TLE:
    ----------------------
    
    90013 03 564A   0433 G 20070213185044300 56 15 0733357+132039 39  +080 05
    90013 03 564A   0433 G 20070213185346700 56 15 0736391+131936 39  +080 05
    90013 03 564A   0433 G 20070213185806100 56 15 0741005+131737 39  +080 05
    27168 02 001A   0433 G 20070213192446000 56 15 0704347+070502 39  +087 05
    27168 02 001A   0433 G 20070213194834900 56 15 0728274+070301 39  +085 05
    90016 03 766A   0433 G 20070213200635900 56 15 0416293+111848 39  +095 05
    90016 03 766A   0433 G 20070213200734200 56 15 0417230+111958 39  +095 05
    90033 05 558A   0433 G 20070213202555900 56 15 0628274+065927 39  +115 05
    90033 05 558A   0433 G 20070213202917000 56 15 0631486+070218 39  +123 05
    90035 05 625A   0433 G 20070213203136200 56 15 1026091+051903 39  +110 05
    90023 04 776A   0433 G 20070213204005700 56 15 0311488-001739 39  +105 05
    90023 04 776A   0433 G 20070213204100200 56 15 0312427-001800 39  +105 05
    91090 06 844A   0433 G 20070213210545500 56 15 0451292+070743 39  +110 05
    91090 06 844A   0433 G 20070213210904700 56 15 0454492+070943 39  +120 05
    90048 05 605B   0433 G 20070213211751200 56 15 0545400+074403 39  +097 05
    90048 05 605B   0433 G 20070213212218100 56 15 0550090+075210 39  +097 05
    90049 05 605C   0433 G 20070213214117400 56 15 0649175+021408 39  +109 05
    90049 05 605C   0433 G 20070213214805400 56 15 0656083+022130 39  +105 05
    
    Strays seen:
    ------------------
    Arianne 44LR+R/B  variable, range 26600 kms
    23201 94 049C   0433 G 20070213192608700 56 15 0704094+072926 39  +095 05
    23201 94 049C   0433 G 20070213193149100 56 15 0709439+075341 39  +085 05
    SL-12 R/B variable, range 37630 kms
    27444 02 029D   0433 G 20070213192608700 56 15 0705066+072856 39  +116 05
    27444 02 029D   0433 G 20070213193328700 56 15 0712206+073649 39  +116 05
    27444 02 029D   0433 G 20070213193956000 56 15 0718428+074346 39  +118 05
    Intelsat 904 geostationary steady
    27380 02 007A   0433 G 20070213203136200 56 15 1025234+051918 39  +113 05
    DMSP 5D-3 F16D debri - interesting variability
    28080 03 048D   0433 G 20070213204100200 56 15 0313297-001101 39  +105 05
    Insat 2A geostationary variable mag 11 to 14,regular few seconds period
    22027 92 041A   0433 G 20070213205829200 56 15 0443027+070732 39  +110 05
    22027 92 041A   0433 G 20070213210515300 56 15 0449447+072249 39  +140 05
    
    Notes:
    -------
    
    (1) Finally, after several "failures" I now have the 6 inch reflector in
        operation for satellite tracking. I still have some minor problems
        to sort out but it is operational and will probably be a permanent
        fixture. I have still to decide how Im going to manage tracking
        LEO satellites with such a small field of view!. The attempt to make
        a BARTEL unit out of the telescopes equatorial mounting failed
        because the program SCOPE is really written for an alt-azimuth
        and it does not display the correct azimuth and elevation when use
        in the equatorial mount version. Trying to use the equatorial mount
        in the conventional astronomical way proved a pain in the "end"
        because the camera view changes orientation as the hour angle
        varies so in the end I used my Altazimuth CoSaTrak mounting.
    
    (2) Quite a change now - previously most geostationary satellites I
        could only see by integrating the images obtained - now I see them
        in "real time" with no problems at all. The mount is kept stationary
        so the geosat appears "stellar like" whilst the stars produce short
        trails during the 2.56 second exposure so its very easy to spot
        a geostationary satellite or other slow moving object.
    
    (3) Most predictions for the geostationary satellites have the object
        outside the field of view. As the field of view is so small its
        almost impossible to do any form of "star hopping" so I do a short
        scan in azimuth and elevation to locate the satellite. This is a
        problem at the moment as the mounting has backlash in elevation
        of about half a degree which is more than the field of view. I
        propose to use my 145mm lens, with another camera, as a"finder" so
        that I can then "starhop" using the bigger field of view (about
        2 degrees).
    
    (4) Also seen, and got a "pretty picture", was the six ASTRA satellites
        above 19 degrees east longitude- I did not measure them because
        the SPACETRACK prediction does not match the actual formation
        shape so not 100% certain which is which.
    
    Cheers
    Greg
    
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