#40 Use Satellite Catalog Information for re-entry dates

open
nobody
None
5
2013-02-04
2011-06-20
Charles Suprin
No

The current decay time algorithm relies on accurate and recent TLE information being available. This may not be available when updated tle's are no longer published (in the case of an infrequently updated system) or are not published after orbital maneuvers (STS-133 and STS-134 fall into this case).

One alternative is to take the decay date from a more permanent source. The satellite catalog <http://celestrak.com/pub/satcat.txt> is one example of this data. However this file is large and probably should not be downloaded as frequently as the TLE's.

A more compact source of information would be nice as well..

Discussion

  • Charles Suprin
    Charles Suprin
    2012-01-28

    Where should additional information about a satellite go? sat_t or a sub structure thereof?

    I have an initial patch for downloading the catalog and adding the catalog entry for a file to the .sat file using a menu entry. (No automatic updates as with the TLE's)

    Now I am looking at adding this information to the sat_t structures. In particular, the launch date, reentry status, and re-entry date. Originally I was going to add them to a structure and add the structure to the sat_t definition. However given that the sat_t definition lives in sgp4sdp4.h it may not know about structures in the src directory. Some of the information is already in sat_t.

    Information available in the category entry includes:
    International ID
    Catalog Number
    Launch Date (if we want to not show satellites in the past using the time-controller.)
    Multiple Name Flag (Could be useful for the satellite editor)
    Payload Flag (useful if we want to implement a filter to eliminate debris and boosters in the satellite selector)
    Operational Status (useful as the operational status in the TLE's but how do we maintain coherency)
    Name (Yes, another place to get names from.)
    Source/Ownership
    Launch Site
    Decay date
    Various orbital parameters
    Orbital Status code (Useful for knowing if TLE's will continue coming.)

     
  • Charles Suprin
    Charles Suprin
    2012-02-10

    Four patches are now added. They add the menus to download the catalog, download code, then finally implement it in the decayed function.