Obs 29 March 2005

From: Greg Roberts (grr@iafrica.com)
Date: Thu Mar 31 2005 - 08:38:34 EST

  • Next message: Greg Roberts: "Geostationary problems"

    Observations 29 March 2005
    ---------------------------------
    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 145mm focal length f/2.5 lens giving a field of view of
    about 2.55 x 1.86 degrees and easily showing 12th magnitude stars.
    Not the best lens optically but the most useful in terms of field
    of view and magnitude penetration.
    
    Data recorded on DVD R/W disks - will be kept for 1 month and then
    re-used - just in case any queries as Im always making mistakes!
    
    Site 0433 : Longitude 18.51294 deg East, Latitude  33.94058 deg S,
    Elevation 10 metres - situated in Pinelands (Cape Town), South Africa
    
    
    90013 03 564A   0433 F 20050329173626200 17 15 0912325+113707 39 S+081 05
    90013 03 564A   0433 F 20050329192752400 17 15 1104319+084311 39 S+080 05
    21768 02 001A   0433 F 20050329173952000 17 15 0616068+070323 39
    21768 02 001A   0433 F 20050329184616400 17 15 0722443+062944 39 S+100 05
    21768 02 001A   0433 F 20050329184836500 17 15 0725048+062811 39 S+100 05
    21768 02 001A   0433 F 20050329184953400 17 15 0726210+062752 39 S+100 05
    21768 02 001A   0433 F 20050329193513200 17 15 0811441+060058 39
    21768 02 001A   0433 F 20050329215818600 17 15 1035054+043507 39 S+088 05
    90033 05 558A   0433 F 20050329180639400 17 15 0701394+062236 39 R+070 05
    90033 05 558A   0433 F 20050329215018400 17 15 1046022+070335 39  +105 05
    90033 05 558A   0433 F 20050329215141800 17 15 1047268+070337 30  +105 05
    90005 99 804A   0433 F 20050329205233700 17 15 0939550+110141 39  +108 05
    90005 99 804A   0433 F 20050329205324900 17 15 0940459+105946 39  +108 05
    
    IMMARSAT 4F1
    28628 05 009A   0433 F 20050329173048000 17 15 0627542+062438 39
    TELECOM 2A
    21813 91 084A   0433 F 20050329210315000 17 15 0935391+085045 39  +098 05
    METEOSAT 6
    22912 93 073B   0433 F 20050329211135000 17 15 1013182+103058 39  +109 05
    SL-12 R/B(20
    28466 04 043D   0433 F 20050329220230000 17 15 1058339+055830 39  +107 05
    EUTELSAT W1
    26487 00 052A   0433 F 20050329220454000 17 15 1109349+052918 39  +098 05
    INSAT 2C
    23731 95 067B   0433 F 20050329212136600 17 15 1019578+081821 39 I+115 05
    EUTELSAT W3A
    28187 04 008A   0433 F 20050329220122000 17 15 1051588+052958 39  +093 05
    
    Comments:
    -------------
    
    (1) Lot of positions for Milstar 5 - the positions around 18h46m were
        obtained when I was looking for #26356 and thought I had found it,but
        later analysis showed it was Milstar 5.
    
    (2) #90032 is a "new" object - however see my later report.
    
    (3) I have not given positions for several other geostationaries observed,
        amongst them being SIRIUS 2 and 3 and the HOTBIRD satellites. There
        are 5  HOTBIRD satellites ( #1,2,3,4 and 6) grouped in a "box" about
        5 arc minutes square. I was  unable to identify which HOTBIRD was which
        so not measured.Magnitude of each was about +8.9.
    
    (4) I am now using a new technique for locating geostationaries.Instead
        of looking at a particular location I now "scan" an area- for example
        this session I scanned in azimuth from 335 to 350 degrees and in
        elevation from 40 to 51 degrees in steps of 1.5 degrees so there is
        some overlap between successive areas.  Due to bright moonlight I
        could not see fainter than 12th magnitude but estimate that on a
        moonless night I should get to magnitude +14 using 128 frame
        integrations which provides one "image" equivalent to a 2.56 second
        exposure . These images are then "stacked" for 100 exposures ( hence
        total exposure time is 256 seconds) which results in trailed stars
        and geostationary satellites showing up as a bright "star".
    
    Cheers
    Greg
    
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