Obs 08 July 2005

From: Greg Roberts (grr@iafrica.com)
Date: Sun Jul 10 2005 - 11:53:11 EDT

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    Observations 08 July 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 25m focal length f/1.4 lens,integrating for 64 frames,
    thus giving an equivalent exposure of 1.28 seconds.The field of
    view was 14.3 x 11.6 degrees and faintest star seen was about
    magnitude 9.2. Theoretically I should have got about a magnitude
    fainter but transparency was poor and image focus was not as sharp
    as I would have liked.  The lens came from a surveillance video camera
    and, whilst maybe good enough to see crooks, was not good enough
    for stellar points.  Not all lenses are high quality.
    Site 0433 : Longitude 18.51294 deg East, Latitude  33.94058 deg S,
    Elevation 10 metres - situated in Pinelands (Cape Town), South Africa
    21798 91 082A   0433 F 20050708172456900 56 15 1518070-004810 39
    21798 91 082A   0433 F 20050708172516100 56 15 1507420+052839 39
    21798 91 082A   0433 F 20050708172536600 56 15 1457220+113231 39
    91034 05 189LEO 0433 F 20050708174145600 56 15 1520560+095253 39
    91034 05 189LEO 0433 F 20050708174157200 56 15 1523050+091751 39
    91034 05 189LEO 0433 F 20050708174207400 56 15 1525180+084113 39
    91034 05 189LEO 0433 F 20050708174218900 56 15 1527400+080107 39
    91034 05 189LEO 0433 F 20050708174220200 56 15 1527520+075503 39
    91034 05 189LEO 0433 F 20050708174227900 56 15 1529290+072624 39
    91034 05 189LEO 0433 F 20050708174238100 56 15 1531590+064421 39
    (1) After having nearly completed my geostationary project I am now
        looking for greener pastures in satellite tracking so decided to
        try wide angle tracking to investigate feasibility of locating
        lost satellites etc. Over the next few sessions I will be testing
        out various camera lenses/techniques with my MINTRON camera.
    (2) This session I set the camera on RA 15h00m Dec +05deg00min which is
        in the Clarke belt and let the CoSaTrak computer program drive
        the altazimuth mounting at sidereal rate for four hours which is
        the recording duration of one DVD disk at medium resolution. At
        the same time I ran a PC program called SKYPATROL which was
        designed for observing meteors. I then "abandoned" the equipment
        whilst it ran unattended and went and watched TV for the next few
        Every minute a "summed" image of all frames obtained in the
        previous minute ( 1500frames) is displayed and saved to a BMP file
        on the hard drive.This produces nearly the same effect as taking
        a 1 minute exposure at night with an ordinary photo camera,
        however you do not see more stars but all objects that were seen
        in the previous minute are recorded at their "normal" intensities.
        At the end of the tracking session ( say of 4 hours duration) one
        has approximately 240 BMP images and one then examines each image
        to see what happened in that minute. Satellites and meteors appear
        as trailed objects as well as other objects such as aircraft,birds
        etc, whilst stars/planets appear as point sources since the camera
        tracked at sidereal rate.
        If the subject looks interesting one can then go to the DVD recording
        to examine the 1500 frames recorded in that particular minute.Each
        frame is time stamped so positional information can be derived.
        It is much quicker to check 240 BMP images than sit through watching
        4 hours of recording.
    (3) At least 14 satellites were seen as follows:
        90055D #20666  SL-6 R/B(2)
        78039B #10793  Delta 1 R/B(1)
        93016B #22566  SL-16 R/B
        91082A #21798  DMSP B5D2-6
        77005B #09786  Delta 1 R/B(1)
        99045B #25893  SL-8 R/B
        76108B #09510  SL-8 R/B
        94077B #23405  SL-16 R/B
        93056B #22788  Atlas Centaur
        87074G #18340  SL-14 R/B
        61031C #00204  SL-14 R/B
        80098B #12445  Atlas Centaur
        Since 91028A is a satellite appearing in CLASSFD.TLE I measured
        three positions. However due to the image scale the positions will
        not be as accurate as those obtained with the 145mm focallength
        lens normally used for positional work ( being about 6x more "course")
    (4) An unknown LEO satellite was observed for which I can find no match
        in my element database. This was fairly slow moving,about magnitude
        +7.5 at maximum to invisibility with a fairly regular variation.
    (5) No geostationary satellites were seen as such since I obviously was
        not able to go faint enough, however three possible flashers were
        seen (- still to be investigated), one of them being SATCOM 1 flashing
        about every 51 seconds to about magnitude 7.
    (6) My conclusions re this lens was that the field of view was too wide
        for precise positional work and the magnitude penetration is not
        sufficient for most optical tracking (this applies to my particular
        city lit skies). An altazimuth mount is not suitable for driving at
        sidereal rate as field rotation is particularly noticeable when close
        to the meridian.Ideally a true equatorial mount should be used.
    (7) On the 9th July I tested a photographic camera (film) 50mm f/1.8 lens
        but have still to examine the results but first impressions are that
        the optical quality was good and I probably got another 2 magnitudes
        fainter.I scanned the same area as on the 8th July. More tomorrow
        after I have examined the results etc.
    (8) A program such as SKYPATROL was written to make an AVI recording
        whenever a meteor was seen. I am certain that the program can be
        used to operate in the same way with satellites. The detection
        sensitivity appears to be adequate and I was in fact able to see
        satellites in the BMP image that I missed in real time. Satellite
        observed in the BMP images should be ideal for photometric use such
        as brightness and magnitude variations as these are clearly shown.
        I intend to try at least one session with completely automated
        tracking of satellites in the CLASSFD.TLE elements database with me
        not being in attendence. I think it can be done on most satellites
        of interest.
        Other meteor detection programs are available- such as UFOCapture
        ( more versatile than SKYPATROL but shareware as opposed to SKYPATROL
        which appears to be freeware)- Im a great supporter of freeware :-))
        Another point "against" UFOCapture is that the manual is in Japanese
        - something I dont plan to learn.
    (9) Sorry this is so long - I feel its worthwhile "publishing" such so
        that other video observers may find it useful - in fact ANY video
        camera sensitive enough to spot satellites will find this technique
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