Re: GPS for ISS transits and iridium flares

From: Kevin Fetter (kfetter@yahoo.com)
Date: Thu Feb 12 2004 - 14:25:56 EST

  • Next message: Thomas Fly: "Re: GPS for ISS transits and iridium flares"

    You mean like this:)
    
    Here's the approx area, where the iss will Buzz Jupiter
    
    ISS             20.0 10.0  0.0  0.5 d 
    1 25544U 98067A   04043.71650473  .00016531  00000-0  15159-3 0  1761
    2 25544  51.6266 244.5270 0007160 158.0764 202.1067 15.67023840298639
    
    12 Feb 2004 17:00:00.00          -37.9164          -179.0460
    12 Feb 2004 17:00:01.00          -37.8691          -178.9852
    12 Feb 2004 17:00:02.00          -37.8220          -178.9242
    12 Feb 2004 17:00:03.00          -37.7744          -178.8641
    12 Feb 2004 17:00:04.00          -37.7271          -178.8034
    12 Feb 2004 17:00:05.00          -37.6796          -178.7431
    12 Feb 2004 17:00:06.00          -37.6322          -178.6826
    12 Feb 2004 17:00:07.00          -37.5850          -178.6218
    12 Feb 2004 17:00:08.00          -37.5373          -178.5620
    12 Feb 2004 17:00:09.00          -37.4898          -178.5018
    12 Feb 2004 17:00:10.00          -37.4424          -178.4413
    
    This is the predicted path for 0 m elevation in terms of the ellipsoid. The ellipsoid is different
    then sea level, so that one thing that must be factored in. For example for my location there's a
    diference of approx 32.7 m between the sea level height and the ellipsoid height.
    
    So for example if I am approx 132.7 m above sea level, then I would be 100 m approx above the
    ellipsoid. And while SGP4/SDP4 uses the old WGS72 datum, the newest datum is ITRF 2000. So which
    datum is used for the obsevers position, will have some effect on the computations.
    
    But then errors in the iss, planet and observer's position will effect the real view.  
    
    So I like to compute where the iss will pass approx across a planet, then send out a prediction,
    so people can watch the iss pass by the planet fairly close, are it passes a few degrees away. It
    makes for a nice view, and people like to watch the show. 
    
    The predictions I generate are good enough for me and others, to see something, that all that
    matters to me.
    
    If tom generates very precise info, good for him. People can use his info, and get a really nice
    view.
    
    Kevin
    
    --- Tom Wagner <wagnert@walnutridge.pvt.k12.ia.us> wrote:
    
    I would imagine that once Tom gets the predictions up for ISS transits of planets, 
    using a GPS unit will almost be a must! 
    
    
    
    =====
    COSPAR Site #1775  Long 75.6910 W, Lat 44.6062 N, altitude 100 metres
    
    
    
    
    __________________________________
    Do you Yahoo!?
    Yahoo! Finance: Get your refund fast by filing online.
    http://taxes.yahoo.com/filing.html
    
    -------------------------------------------------------------------------
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:  
    http://www.satobs.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Thu Feb 12 2004 - 15:39:33 EST