An economical semianalytical orbit theory for microcomputer applications
Abstract
An economical algorithm is presented for predicting the position of a satellite perturbed by drag and zonal harmonics J2 through J4. Simplicity being of the essence, drag is modeled as a secular decay rate in the semimajor axis (retarded motion) with the zonal perturbations modeled from a modified version of Brouwers formulas. The algorithm is developed as an alternative onboard orbit predictor; a back up propagator requiring low energy consumption; or a ground based propagator for microcomputer applications (e.g., at the foot of an antenna). An O(J2) secular retarded state partial matrix (matrizant) is also given to employ with state estimation. The theory has been implemented in BASIC on an inexpensive microcomputer, the program occupying under 8K bytes of memory. Simulated trajectory data and real tracking data are employed to illustrate the theory's ability to accurately accommodate oblateness and drag effects.
 Publication:

24th AIAA Aerospace Sciences Meeting
 Pub Date:
 January 1986
 Bibcode:
 1986aiaa.meetT....G
 Keywords:

 Computer Techniques;
 Microcomputers;
 Orbital Mechanics;
 Satellite Perturbation;
 Airborne/Spaceborne Computers;
 Decay Rates;
 Eccentric Orbits;
 Orbit Perturbation;
 Orbital Elements;
 Satellite Drag;
 Trajectory Analysis;
 Astrodynamics