Development and Test of a Space Capable Miniaturized GPS/GNSS Receiver for Space Applications

Abstract

GPS receiver (GPSR) has become one of the most important navigation systems for more than two decades. Though GPS system was designed for near Earth navigation originally, it’s widely used in high dynamic environment such as Low Earth Orbit (LEO). Since a space capable GPSR is able to provide timing and navigation information for spacecraft to determine the orbit, attitude reference, antenna pointing direction, and operations, it is one of the essential components of spacecraft. However, a space-grade GPSR is technology sensitive and under export control. In order to overcome export control, National Space Organization (NSPO) has completed development of self-reliant space-grade GPSR in 2014. The NSPO in-house built GPSR is a software-based receiver which only uses generic chips. Compared with hardware-based GPSR, the functionality expansion of software-based receiver is more flexible. In addition, due to the utilization of generic chips, the NSPO GPSR consumes less power and lighter in mass. The NSPO GPSR has passed its qualification tests and planned to fly on board the FORMOSAT-7 Reflectometry (FS-7R) satellite. Because of the excellent performance and lower cost, the NSPO GPSR is also planned to fly with future FORMOSAT series satellite, university CubeSat, sounding rocket and so on. One key feature of the space-grade GPS receiver is capable to overcome the high Doppler shifts and Doppler shift rates of the high dynamics environment of LEO. In this paper, the design and development of the NSPO GPSR will be presented as well as the performance tested with a simulated high dynamical environment. Some unique features of the NSPO GPSR will also be highlighted, such as the expansion of GPS/GNSS-Reflectometry (GNSS-R) receiver. In addition, the environmental tests are needed to perform to verify that the NSPO GPSR is compliant with its specification and ready to fly with LEO satellite and sounding rocket. The conducted environmental tests will also be described. Through the endeavor of developing and testing of the in-house built GPSR, NSPO has not only obtained the self-development capability in meeting a high-quality and space-qualified standard, but also controlled one of the satellite key technologies.