New Trends For Space Based Positioning

Standard space based positioning approach include the full development and installation of GPS space receiver in both satellites and space vehicles such as stations or ships. The current limitations are on the cost, size, power consumption, dimensions as well as robustness against intentional disruption. This paper propose some emerging techniques well known for ground applications and their applicability to space applications. Particularly, applications of snapshot positioning in space, aiding of data from ground, ground to space code transmissions and space to ground signal transmission are analyzed. As the key point for these applications or positioning approaches is the available signal power and the data bandwidth overhead, the paper proposes three scenarios for analysis and simulation. Proposed scenarios are LEO, GEO and Spaceship in outer GEO mission. The simulations analyze the C/N0 versus the integration time, the cumulative distribution function of the power level, satellite visibility, range accuracy and finally compares position availability performances. Theoretical results are compared with real signal acquired from a realistic LEO applications: The Space Communication and Navigation ( SCaN) testbed currently under development by Qascom with ESA and NASA and installed in the International Space Station ( ISS). Conclusion and tradeoff analysis is provided at the end of the paper.