Abstract
The navigation techniques for spacecrafts are based on different systems or sensors, depending on the specific mission. The spacecrafts operating near the Earth surface (LEO missions for example) can use GPS to estimate position, speed and, in more advanced applications, attitude too. For interplanetary missions, GPS is unsuitable, thus other systems have to be applied. In both cases, inertial sensors are always applicable for navigation and attitude determination, even if they have some disadvantages. In the field of spacecrafts navigation, several algorithms and systems have been developed and patented in recent years. In this paper, the most relevant patents presented in recent years, concerning spacecraft navigation, have been reviewed. The following fields have been covered: i) application of GPS for spacecraft navigation, ii) application of stars trackers, or more in general celestial sensors for attitude determination, iii) application of video and radio systems for navigation and control purposes. Furthermore, some proposals of integration among different navigation systems will be presented. This review considers various applications, emphasizing main advantages and weaknesses of the proposed solutions and suggesting some possible future developments.
Keywords: Spacecraft navigation, GPS, star trackers, celestial sensors, Algorithms, Globastar constellations, Interplanetary Navigation, navigation signals, satellite constellations, GLONASS signals
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