RE: OGO 1

From: Chris Peat (chris.peat@dlr.de)
Date: Wed Jan 16 2008 - 09:51:48 UTC

  • Next message: Brad Young: "RE: OGO 1"

    Hi all,
    The Heavens-Above site doesn't properly handle pass predictions for objects
    which are not in low Earth orbit. I am in the process of updating the
    algorithms, and the pass summary page has already been updated, so it finds
    the OGO 1 "passes", even though they can last several hours. However, the
    pass details page uses an old algorithm, and this causes the error. The
    details page will be updated soon, so please bear with me until then. For
    geostationary satellites, which have passes of essentially infinite length,
    a new kind of reporting table will be needed.
    
    Best wishes,
    Chris Peat
    
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    This error also occurs for NavStars at 20000 km altitude
    , even for ICO F2 #26857 in 10300 km circular orbit.
    
    EXPLORER 38 in 5800 km circular orbit is OK.
    
    For an elliptic orbit like #31863's (Breeze tank)
    a pass at 5000 km altitude is OK, but one at 5900 is not!
    
    For GEOsync satellites it doesn't even find visible passes,
    probably because they are above (or below!) 10 degrees
    elevation for week-long periods or more.
    For InSat 2D slightly below geosync I have a "pass"
    on Jan.22, the last "culmination" above 10 degrees with a dip below.
    Using a starting date of '54474' it finds the first "culmination"
    above 10 degrees, but also a strange "pass" the following day.
    15 Jan 12.5 02:45:09 10 WSW 06:09:43 13 WSW 09:41:46 10 WSW
    16 Jan 13.7 19:20:05 10 SW  12:07:00 10 SW  12:07:00 10 SW
     Starting date of '54479' shows 15 Jan and 22 Jan, but not the
    16 Jan "pass", nor other days when InSat 2D is constantly above 10 degrees 
    from my horizon.
    
    > Interestingly, when you click on the date in Heavens Above for
    > details, it generates the following error (Chris Peat, please note)...
    >
    > Microsoft VBScript runtime error '800a01a8'
    >
    > Object required: ''
    >
    > /PassDetails.asp, line 332
    
    
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