Optical 02 June 2007

From: Greg Roberts (grr@telkomsa.net)
Date: Sun Jun 03 2007 - 10:51:28 EDT

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    Observations 02 June 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 50mm focal length f/1.8 lens,integrating for 96 frames
    which is equivalent to an exposure of 1.92 seconds per image.
    
    Site 0433 : Longitude 18.51294 deg East, Latitude  33.94058 deg S,
    Elevation 10 metres - situated in Pinelands (Cape Town), South Africa
    
    
    OPS 9845 - DMSP  mag 5.5 to invisible - variable
    13736 82 118A   0433 F 20070602163519400 56 15 1044170+160906 39  +055 05
    SL-14 R/B  Mag +6.5 steady
    12880 81 098B   0433 F 20070602164602900 56 15 1043380+163042 39  +065 05
    OPS 8364 - DMSP  mag 6.0 to invisible - variable
    06787 73 054A   0433 F 20070602165201500 56 15 1048460+192406 39  +060 05
    Cosmos 1707  mag 4.0 steady
    16326 85 113A   0433 F 20070602165535100 56 15 1039260+160944 39  +040 05
    SL-14 R/B  mag 6.0 steady
    19791 89 009G   0433 F 20070602165954200 56 15 1111240+151801 39  +060 05
    SL-8 R/B  mag 3.0 steady
    25723 99 022C   0433 F 20070602171510100 56 15 1124430+161901 39  +030 05
    Iridium 69 mag +5.0 variable
    25319 98 026A   0433 F 20070602171542800 56 15 1059310+175940 39  +050 05
    Thor Agena rocket mag 4.5 steady
    01245 65 016J   0433 F 20070602172030400 56 15 1107480+182432 39  +045 05
    Iridium 76  mag 6.0 steady
    25432 98 048B   0433 F 20070602172038600 56 15 1129060+190041 39  +060 05
    SJ-6D mag 3.5 steady
    29506 06 046B   0433 F 20070602173313400 56 15 1130060+162208 39  +035 05
    Argos mag 6.5 steady
    25634 99 008A   0433 F 20070602174549700 56 15 0922440+093136 39  +065 05
    Atlas 5 centaur  mag 7.0 variable, range 8670 kms
    28473 04 048B   0433 F 20070602175953100 56 15 0950500+162519 39  +070 05
    Meteor 1-26  mag 6.0 steady
    09481 76 102A   0433 F 20070602180442400 56 15 0948390+114024 39  +060 05
    Delta 1 Rocket body mag 6.5 steady, range 3240 kms
    14051 83 041B   0433 F 20070602181419700 56 15 0946190+112021 39  +065 05
    SL-8 R/B mag 7.0 steady
    18710 87 106B   0433 F 20070602181543000 56 15 1003200+132321 39  +070 05
    Delta 2 R/B mag 6.5 steady, range 3250 kms
    21965 92 027B   0433 F 20070602181737500 56 15 0954320+111940 39  +065 05
    Delta 1 R/B  mag 7.0 steady
    10517 77 118B   0433 F 20070602185058200 56 15 1036080+134512 39  +070 05
    Delta 2 R/B mag 6.5 steady, range 2620 kms.
    24809 97 025B   0433 F 20070602185647600 56 15 1043170+164839 39  +065 05
    
    
    Notes:
    --------
    
    (1) Satellites observed whilst looking for unknowns - nothing particularly
        exciting about them.
    
    (2) Am now occupying my time with improving the determination of orbital
        elements of unknown satellites and have made some very good progress.
    
        Using the method of Gauss ( 3 times and three positions) I am now able
        to determine the parameters of most satellites to within a few percent
        of the actual value at the time of observation - ALL the parameters are
        very close to the actual values except for a few percent error in the
        orbital period - usually of the order of 3 - 5 minutes after one day
        but in some cases within 5 minutes after 5 days. This applies to LEO
        as well as MEO satellites eg 63 degree inclination, mean motion
        around 2 revs per day. The procedure generates 18 equations in 18
        unknowns but using the Lagrange coefficients f and g, as well as
        using the Stumpff functions and state vectors etc and applying the
        conservation of angular momentum, some valid approximations can be
        made which gives an initial solution, then by a process of iteration
        one homes in on the correct values that fit the observations.
    
        Full details of the method used may be found in "Orbital Mechanics
        for Engineering Students" by Howard D.Curtis (2005) - an excellant
        book on ALL aspects of orbital mechanics with lots of problems and
        detailed solutions. Preliminary tests indicate that a minimum arc
        covering 2 - 3 minutes in time is necessary to get the right answer.
       Anything less will only provide the RA of Node and the inclination.
       For the  approximations made in the computation it is not wise to use
       too long  an arc and a maximum of 10 degrees of the satellites orbit is
        recommended in the literature.
    
        Further testing is being done but so far results are extremely
        encouraging - ( something I did NOT expect when I started as I did not
        consider it possible to derive an eccentric orbit from a very small
        arc of the satellites orbit!)
    
    
    
    
    Cheers
    Greg
    
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