Low earth orbit satellite propagators

Du Plessis, Jan Abraham Francois (1999-12)

Thesis (M.Ing.) -- University of Stellenbosch, 1999.

Thesis

ENGLISH ABSTRACT: The objective of this study was to implement an orbital propagation algorithm, which could be used for the purpose of mission planning and hardware-in- the-loop simulations for the SUNSAT microsatellite. Different propagation algorithms were investigated in order to find one for which the initial conditions for the propagator was freely obtainable and that satisfied the accuracy specification as determined by the onboard activities. The SGP4 analytical algorithm was selected for this purpose. Along with the propagation of the position of the satellite in its orbit, different models were investigated and implemented for modelling the space environment as the sensors observe it onboard the satellite. A conceptual study was performed on methods to improve the quality of the orbital predictions by the combination of sensor measurements with an orbital propagation algorithm in an extended Kalman filter. Knowledge was gained and documented in the field of astrodynamics and it was applied in a practical situation during the launch and operation of SUNSAT.

AFRIKAANSE OPSOMMING: Die doelwit van hierdie studie was die implementering van 'n wentelbaan voorspellings-algoritme wat gebruik kon word vir missie-beplanning en apparatuur- in-die-lus simulasie van die SUNSAT mikrosatelliet. Verskeie voorspellings algoritmes is ondersoek in 'n poging om 'n algoritme te vind waarvan die begintoestande algemeen beskikbaar is en wat aan die vereistes vir akkuraatheid, soos bepaal deur die aktiwiteite aan boord van die satelliet, voldoen. Die SGP4 analitiese voorspellings-algoritme is gekies vir hierdie doel. Saam met die voorspelling van die posisie van die satelliet in die wentelbaan is verskeie modelle wat die ruimte omgewing beskryf soos wat dit deur die sensore waargeneem word, ondersoek en gelmplementeer. 'n Ondersoek in beginsel is ingestel na metodes wat gebruik kan word om die kwaliteit van die wentelbaan-voorspellings te verbeter deur sensor-lesings en 'n voorspellingsalgoritme te kombineer in 'n uitgebreide Kalman-filter. Kennis is versamel en gedokumenteer in die studieveld van ruimte-dinamika en hierdie kennis is prakties toegepas tydens die lansering en bedryf van SUNSAT.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/51326
This item appears in the following collections: