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 http://www.coastalbend.edu/acdem/math/sats/rv2el.txt Both SATFIT and SATID have been updated. A demonstrator program, RV2TLE, can also be found on the site http://www.coastalbend.edu/acdem/math/sats/ 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 campbel7@the-i.net --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.719 / Virus Database: 475 - Release Date: 7/12/2004 ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Mon Nov 21 2005 - 23:59:45 EST