Wrong Metop Data with H.A.

From: Gerhard HOLTKAMP (grd.holtkamp@t-online.de)
Date: Fri Jul 14 2006 - 15:48:49 EDT

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    Heavens-Above allows you already to select Metop (MetOp-A) but be advised that 
    you should not yet generate any predictions for it with H.A. as their orbit 
    elements are about half a revolution out of step with the actually planned 
    ones (at least at the moment of this posting - 19 UTC, 14-JUL-06). Maybe they 
    fix it before Monday's launch; otherwise as soon as Spacetrack posts Metop 
    elements after the launch the situation will probably remedy itself. (So a 
    day after launch you should be safe.)
    
    The following is the planned insertion state vector for Metop (which I got 
    from Metop flight dynamics):
    
    Elements in J2000.
    EPOCH: 2006/07/17-17:36:53.560 UTC
    X 522.81136
    Y -2427.98222
    Z -6764.74918
    Vx -1.8691329
    Vy -6.8111776
    Vz 2.30034444
    
    From this I get the following TLEs (which I already posted earlier):
    
    Metop Sep
    1 99999U 06099A   06198.73395324  .00000028  00000-0  26562-4 0     1
    2 99999  98.7337 257.5914 0024535 156.6977 131.5842 14.21428546     1
    
    I should add that these TLEs are not as perfect as I would like them. They 
    show deviations up to 30 km from the numeric propagation of the state vector 
    (Usually when generating TLEs out of state vectors my deviations are only 
    about 2 or 3 km - I don't know why I got this fairly large deviation here.) 
    Still this would mean an error of only 4 seconds or so and the above TLEs 
    should be more than adequate to locate Metop in the hours after launch. (And 
    keep in mind that the insertion might not be perfect! I think 2 or 3 seconds 
    either way might not be uncommon.)
    
    Gerhard HOLTKAMP
    Darmstadt, Germany
    
    
    
    
    
    
    
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