Research Online: Navigation augmentation based on LEO communication satellite constellations

March 16, 2018  - By , and
Image: GPS World

Presented at ION International Technical Meeting 2018

The main objective of this work is to investigation the feasibility and performances of LEO communication satellite constellations as potential navigation augmentation platforms. The further examination of the existing and upcoming LEO communication satellite constellations has been conducted, such as Iridium, Globalstar, Teledesic, One Web, Boeing, SpaceX, Samsung, etc. The comprehensive performances of LEOs for navigation augmentation are evaluated and analyzed in terms of constellation characteristics, footprint, coverage, signal strength, dilution of precision (DOP, including GDOP, PDOP, VDOP, HDOP), and number of in-view satellites, with comparison of these to the current GPS, Galileo and BeiDou systems. The results showed that LEOs present superior performances compared with GNSS systems, and demonstrate promises as navigation augmentation platforms for challenging environments.

Moreover, the real-time signal-aided navigation method is explored, from user geometry and signal ranging errors to position errors. Then, we proposed a navigation system based on signals of opportunity from LEO platform. The proposed system relay on a terrestrial benchmark network consists of several monitoring stations with time synchronization. It would acquire the downlink communication signal from LEO platforms, and then estimate the time difference of arrival (TDOA) between stations with a correlation-based blind detection algorithm. The TDOA estimations and geographical position information are utilized to develop the time-delay-based spatio-temporal distribution model, which can determine the user’s position by matching the model with its estimated TDOA values. The proposed navigation system can operate stand-alone and facilitates the integration of communication and navigation system.

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