Space Track API - Problems

Date: Mon Aug 27 2012 - 14:17:47 UTC

  • Next message: Björn Gimle: "Re: Regarding Geos"

    After a couple of days playing with the API, I found another
    problem of the available functions (the first one is the 
    missing 3 line format):
    If one wants to download the latest TLE for ALL the objects 
    (bulk catalog), two ways can be used:
    1) request the latest elements for all the objects using such
    a query:
    .../NORAD_CAT_ID/1--40000/sortby/EPOCH desc/sublimit/1
    unfurtunately this solution generates 40000 unions resulting
    in a query that is too long to work properly. 
    Try yourself and you will see that this method works only for
    a very limited range of NORAD_CAT_ID.
    I don't know if the situation will change later (after the test
    phase), but I fear this will not work.
    2) request a larger number of TLEs (let say 20.000) 
    starting from the new ones:
    .../FILE/>xxxxxx/oderby/FILE desc/sublimit/20000
    which is the solution abopted by my program.
    However also this solution doesn't work completely since:
    A) some elements are acquired only once in a few days 
    and they are not in the first 20.000 objects so they are 
    not downloaded!!!
    If you compare the bulk.txt file after the first download, more 
    than 3000 Objects are missing!!!! (Most of them are DEB)
    B) if we want all the elements we have to generate a traffic 
    much larger than actually required. (e.g. tents of MB against 
    0.8 MB of the old zip bulk file).
    (this method works well only to keep the bulk file up-to-date,
    e.g. once a day).
    If someone of you has got any idea on how to retrieve only 
    the last TLEs of each object, I will be glad to implement is 
    in the downloader.
    Best regards,
    Seesat-l mailing list

    This archive was generated by hypermail 2b29 : Mon Aug 27 2012 - 14:19:03 UTC