this procedure is the sgp4 prediction model from space command. this is an
updated and combined version of sgp4 and sdp4, which were originally
published separately in spacetrack report //3. this version follows the
methodology from the aiaa paper (2006) describing the history and
development of the code.
author : david vallado 719-573-2600 28 jun 2005
inputs :
tle - initialised structure from sgp4init() call.
tsince - time since epoch (minutes)
outputs :
r - position vector km
v - velocity km/sec
return code - non-zero on error.
1 - mean elements, ecc >= 1.0 or ecc < -0.001 or a < 0.95 er
2 - mean motion less than 0.0
3 - pert elements, ecc < 0.0 or ecc > 1.0
4 - semi-latus rectum < 0.0
5 - epoch elements are sub-orbital
6 - satellite has decayed
procedure sgp4
this procedure is the sgp4 prediction model from space command. this is an updated and combined version of sgp4 and sdp4, which were originally published separately in spacetrack report //3. this version follows the methodology from the aiaa paper (2006) describing the history and development of the code.
author : david vallado 719-573-2600 28 jun 2005
inputs : tle - initialised structure from sgp4init() call. tsince - time since epoch (minutes)
outputs : r - position vector km v - velocity km/sec return code - non-zero on error. 1 - mean elements, ecc >= 1.0 or ecc < -0.001 or a < 0.95 er 2 - mean motion less than 0.0 3 - pert elements, ecc < 0.0 or ecc > 1.0 4 - semi-latus rectum < 0.0 5 - epoch elements are sub-orbital 6 - satellite has decayed
locals : am - axnl, aynl - betal - cosim , sinim , cosomm , sinomm , cnod , snod , cos2u , sin2u , coseo1 , sineo1 , cosi , sini , cosip , sinip , cosisq , cossu , sinsu , cosu , sinu delm - delomg - dndt - eccm - emsq - ecose - el2 - eo1 - eccp - esine - argpm - argpp - omgadf - pl - r - rtemsq - rdotl - rl - rvdot - rvdotl - su - t2 , t3 , t4 , tc tem5, temp , temp1 , temp2 , tempa , tempe , templ u , ux , uy , uz , vx , vy , vz inclm - inclination mm - mean anomaly nm - mean motion nodem - right asc of ascending node xinc - xincp - xl - xlm - mp - xmdf - xmx - xmy - nodedf - xnode - nodep - np -
coupling : getgravconst- dpper dspace
references : hoots, roehrich, norad spacetrack report //3 1980 hoots, norad spacetrack report //6 1986 hoots, schumacher and glover 2004 vallado, crawford, hujsak, kelso 2006