Flexible Architecture for Space Navigation

摘要

Space-borne navigational receivers are used for accurate and stable navigation over an extended period of time and can provide valuable navigation, guidance and control functions for a variety of space missions. They can also be used for surveillance and remote sensing operations. The demanding requirements need to be met with superior performance, flexible architecture immune to obsolescence and rapid development cycle. Although the specific requirements will depend on the mission, the overall navigational principle will be central to all of these missions. In general, they involve some relatively minor changes over a few central architectures. Because of the limited applications of the space borne systems, the conventional hardware based architecture is not cost effective; nor does it provide a timely adaptation for specific missions. Software digital receivers provide this flexibility, performance, adaptability to various signals and scenarios, and at the same time ensure vertical growth. The open architecture software GPS receiver platform, developed at CRS, offers the modular design capabilities that allow easy and efficient integration of various advanced signal-processing techniques with the conventional GPS receiver blocks. It provides a reconfigurable solution capable of incorporating new design concepts. A few standard hardware platforms suitable for different space missions (depending on the application, orbit, lifecycle, cost etc.) would provide cost effective and timely solutions for most of the future space systems. The different requirements are easily met using software modifications. The software modifications can also be used during the flight, enabling the same platform for various phases of the mission. The receiver platform has been used to implement a variety of advanced navigational systems. Optimum use of the resources necessary for space missions also requires novel receiver architecture. Novel architectures suitable for flexible implementation and particularly suitable for space missions have been developed and demonstrated. In this paper we describe the implementation of some of these applications, particularly those employing high dynamics and maneuvers.