masterThesis
Desenvolvimento e testes de software de um receptor de GPS para uso espacial
Fecha
2011-03-25Registro en:
RAPOSO, Tullio Emmanuel Messias. Desenvolvimento e testes de software de um receptor de GPS para uso espacial. 2011. 135 f. Dissertação (Mestrado em Automação e Sistemas; Engenharia de Computação; Telecomunicações) - Universidade Federal do Rio Grande do Norte, Natal, 2011.
Autor
Raposo, Tullio Emmanuel Messias
Resumen
Spacecraft move with high speeds and suffer abrupt changes in acceleration. So, an
onboard GPS receiver could calculate navigation solutions if the Doppler effect is taken into
consideration during the satellite signals acquisition and tracking. Thus, for the receiver
subject to such dynamic cope these shifts in the frequency signal, resulting from this effect, it
is imperative to adjust its acquisition bandwidth and increase its tracking loop to a higher
order. This paper presents the changes in the GPS Orion s software, an open architecture
receiver produced by GEC Plessey Semiconductors, nowadays Zarlink, in order to make it
able to generate navigation fix for vehicle under high dynamics, especially Low Earth Orbit
satellites. GPS Architect development system, sold by the same company, supported the
modifications. Furthermore, it presents GPS Monitor Aerospace s characteristics, a
computational tool developed for monitoring navigation fix calculated by the GPS receiver,
through graphics. Although it was not possible to simulate the software modifications
implemented in the receiver in high dynamics, it was observed that the receiver worked in
stationary tests, verified also in the new interface. This work also presents the results of GPS
Receiver for Aerospace Applications experiment, achieved with the receiver s participation in
a suborbital mission, Operation Maracati 2, in December 2010, using a digital second order
carrier tracking loop. Despite an incident moments before the launch have hindered the
effective navigation of the receiver, it was observed that the experiment worked properly,
acquiring new satellites and tracking them during the VSB-30 rocket flight.