Accession Number : ADA267281


Title :   Rapid Determination of Satellite Visibility Periods


Corporate Author : AIR FORCE ACADEMY COLORADO SPRINGS CO


Personal Author(s) : Alfano, Salvatore ; Negron, David, Jr ; Moore, Jennifer L


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a267281.pdf


Report Date : Jun 1992


Pagination or Media Count : 17


Abstract : This paper presents a numerical method to rapidly determine the rise- set times of satellite-satellite and satellite ground station visibility periods, with the line-of-sight corrected for an oblate Earth. The algorithm uses space curve modeling technique known as parabolic blending to construct the waveform of the visibility function, psi (t), versus time. The waveform is produced from either uniform or arbitrarily spaced abscissa points, from which rise-set times are obtained by extracting the real roots of a localized cubic polynomial. This algorithm works for all orbital eccentricities and perturbed satellite motion, provided the visibility function, psi(t), does not become discontinuous as it could from thrusting or deploying a tether. For this study, the rise-set truth table is constructed using a standard five second step-by- step integration with a linear interpolator to locate the exact crossing times. ne simulation results from this algorithm are almost identical to those obtained by modeling satellites subject to first order secular perturbations caused by mass anomalies, but generated in considerably less time. Advantages of this numerical method include compact storage and ease of calculation, making it attractive for supporting ground-based and autonomous onboard satellite operations.... Mathematical models, Numerical methods and procedures, Parabolas, Visual surveillance, Tracking, Visibility, Observation satellites (artificial).


Descriptors :   *ORBITS , *ARTIFICIAL SATELLITES , *SATELLITE COMMUNICATIONS , MATHEMATICAL MODELS , ALGORITHMS , LINE OF SIGHT , EARTH ORBITS , OBSERVATION , MOTION , TIME , POLYNOMIALS , VISUAL SURVEILLANCE , GROUND STATIONS , OPTICAL TRACKING , SURVEILLANCE , NUMERICAL METHODS AND PROCEDURES , GROUND BASED , PERTURBATIONS , PARABOLAS , VISIBILITY , CURVE FITTING , ECCENTRICITY , INTEGRATION , TRACKING , WAVEFORMS , MASS , REPRINTS , SIMULATION , ANOMALIES


Subject Categories : Unmanned Spacecraft
      Spacecraft Trajectories and Reentry


Distribution Statement : APPROVED FOR PUBLIC RELEASE