New Program

From: Scott Campbell (
Date: Mon Nov 21 2005 - 23:50:35 EST

  • Next message: Russell Eberst: "2005NOV21.OBS"

    Been having a little trouble getting this message to post, so after several
    tries, I hope it only goes through once.
    I just put the finishing touches on an algorithm to produce SGP4 / SDP4 mean
    orbital elements from a position and velocity vector at epoch.  The
    algorithm essentially reverses the process of SGP4 which takes mean elements
    and produces a position and velocity vector.
    I needed the ability to advance a TLE to another epoch for SATFIT and
    SATID.  Up until today, I had been using a numerical method that converged
    to the mean elements most of the time...but this one gets exact results
    every time.
    If anyone would like this capability for their programs, I have posted the
    algorithm in C++ at
    Both SATFIT and SATID have been updated.  A demonstrator program, RV2TLE,
    can also be found on the site
    RV2TLE does essentially the same thing that VEC2TLE does, but the interface
    is easier for me to work with.
    Scott Campbell
    Beeville, Texas
    Cospar 6226 28.4861N 97.8194W 107m
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