RE: a general decrease in the numbers of TLEs since November?

From: Geoffrey E. Forden (forden@MIT.EDU)
Date: Tue Jan 06 2009 - 23:05:10 UTC

  • Next message: Geoffrey E. Forden: "RE: a general decrease in the numbers of TLEs since November?"

    Thanks to all who looked!  My friend looks at the daily TLEs (he downloads
    the daily file every day) and has noticed a 40% drop in its size starting in
    November.  So while the total catalog doesn’t change, the daily TLEs really
    do seem to have dropped.  I'm in the process of trying see if there is an
    altitude dependence (which might allow me to see if it is the Texas radar
    fence that is giving a problem.)  
      So far, this is all based on file sizes but I hope to be able to say
    something more quantitative soon.
    Best regards, Geoff
    
    -----Original Message-----
    From: Daniel Deak [mailto:dan.deak@sympatico.ca] 
    Sent: Tuesday, January 06, 2009 5:56 PM
    To: seesat-l@satobs.org
    Subject: RE: a general decrease in the numbers of TLEs since November?
    
     
    Hi,
    
    I just loaded the full satellite catalog file from Space-Track and it shows
    11669 objects, a number that I've never seen really drop. The youngest elset
    was 0.5 day old and the oldest was at 30.3. The description on Space-Track
    says : These files are generated twice a day, every day and consist of the
    most recent elset for every object in the specified group that has received
    an update within the past 30 days.
    
    So there is more objects up there, but I guess the great majority of them
    (those that have been catalogued) are in the elset file. High altitude
    objects look difficult to track...
    
    
    Daniel Deak
    Webmestre, site Obsat
     
    COSPAR site 1748 : 45.8813°N, 72.5317°W, 90 m., UTC-5:00
     
    Site en francais sur les satellites:
    French-language satellite web site : http://www.obsat.com
    
    -----Message d'origine-----
    De : Geoffrey E Forden [mailto:forden@MIT.EDU] 
    Envoyé : 6 janvier 2009 14:36
    À : seesat-l@satobs.org
    Objet : a general decrease in the numbers of TLEs since November?
    
    An analyst I respect a lot has told me that the number of cataloged TLEs
    posted by space-track has decreased by 40% since November (since roughly
    when those six satellites, including the CLUSTER II satellites, were lost).
    I'm only able to check a few satellites at a time and was wondering if
    anyone had also noticed this? Thanks!
    
    
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