Optical 21 October 2008

From: Greg Roberts (grr@telkomsa.net)
Date: Wed Oct 22 2008 - 10:15:22 UTC

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    Observations 21 Oct 2008
    -------------------------------
    
    Cosatrak 1 (Computerised satellite Tracking System).
    Camera mount now carries two systems that can be operated
    together as two totally different sytems and computers used.
    Generally the DSI Pro II camera will be used for high altitude
    slow moving objects. Tests seem to indicate that its sesnitivity
    is comparable to the MINTRON ( possibly better) but as its not
    possible (?) to time stamp to better than 1 second accuracy the
    time resolution is not good enough for LEO objects.
    
    (1) 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 135mm focal length f/2.8 lens,integrating for 128 frames
    which is equivalent to a max exposure of 2.56 seconds maximum
    per image. Field of view 2.7 x 2.1 degrees.
    Individual frames are video time stamped with GPS derived signal.
    
    (2)Meade DSI Pro II Monochrome CCD camera without filters.
    using integration times of 20 sec min to 60 seconds maximum
    depending on brightness of sky in particular area.No image
    processing done but dark field applied.
    Used with 200mm focal length f/2.8 Nikkon telephoto lens,
    field of view 1.88 x 1.40 degrees. Can get to magnitude 13
    or so in less than 20 seconds exposure.
    Exposure time to nearest second inserted into image FITS header
    from PC clock which is automatically checked every minute against
    GPS signal.
    
    Site 0433 : Longitude 18.51294 deg East, Latitude  33.94058 deg S,
    Elevation 10 metres-situated in Pinelands (Cape Town),South Africa
    
    
    For CLASSFD.TLE:
    -------------------------- 
    96145 96 645A   0433 F 20081021182358000 56 15 2022361+103712 39  +130 05
    96145 96 645A   0433 F 20081021182929000 56 15 2028175+110534 39  +130 05
    96076 96 576A   0433 F 20081021190950000 56 15 2230218+035443 39  +125 05
    96076 96 576A   0433 F 20081021191602000 56 15 2237551+041150 39  +125 05
    96076 96 576A   0433 F 20081021194022000 56 15 2307289+051948 39  +125 05
    96062 96 562A   0433 F 20081021191825000 56 15 2201436+034845 39  +110 05
    96062 96 562A   0433 F 20081021192156000 56 15 2205150+034834 39  +125 05
    96032 96 032A   0433 F 20081021192653000 56 15 2223347-053743 39  +120 05
    96032 96 032A   0433 F 20081021192812000 56 15 2224532-053340 39  +120 05
    96032 96 032A   0433 F 20081021193050000 56 15 2227340-052557 39  +120 05
    96038 96 538A   0433 F 20081021194945000 56 15 2110229+033923 39  +125 05
    96038 96 538A   0433 F 20081021195727000 56 15 2118059+040446 39  +125 05
    96012 96 512A   0433 F 20081021200905000 56 15 0146416+021006 39  +125 05
    96012 96 512A   0433 F 20081021201433000 56 15 0151489+020813 39  +125 05
    96055 96 555A   0433 F 20081021201944000 56 15 2000030-060348 39  +125 05
    96055 96 555A   0433 F 20081021202435000 56 15 2004388-054855 39  +125 05
    
    Strays seen:
    -------------
    TELSTAR 11 geostationary, varying +10 >+12 - some bright flashes
    23413 94 079A   0433 F 20081021184454000 56 15 2217168+004205 39  +100 05
    AFRISTAR geostationary
    25515 98 063A   0433 F 20081021194022000 56 15 2307517+052506 39  +105 05
    EUTELSAT W3 geostationary
    25673 99 018A   0433 F 20081021194022000 56 15 2310326+052548 39  +105 05
    ARABSAT 1A geostationary
    15560 85 015A   0433 F 20081021200905000 56 15 0143129+024701 39  +120 05
    
    
    
    Notes:
    ------
    (1) Usual story - troubled by clouds until I had to stop.
    
    (2) The magnitudes of the 96*** objects above are probably 2- 3 magnitudes
    fainter than reported. Due to their faintness and high inclinations in
    most cases I had to automatically track on the predicted track which means
    the image integrates. I was using exposures as long as 50 seconds for some
    of the objects.
    
    (3) 96012   maybe slight variability
        96032   appeared to be steady
        96062   variable, period VERY roughly around 50-60 seconds. Rate it
                     as "easy"
        96076   slight variability
        96145   appeared steady
    
    (4) During the "dark" of the moon I will only attempt to track/locate the
        fainter satellites. The bright ones can be done in moonlight.
    
    (5) My next job is to add peltier cooling to my camera. As summer approaches
          the operating temperature of the camera increases and the picture becomes
          more "noisy" with dead or hot pixels that could be mistaken for a faint
          satellite. An efficient peltier could decrease the temperature by 15 deg C 
    or
          more and reduce the noise quite dramatically.
    
    Cheers
    Greg
    
     
    
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