The perspective from Asia concerning the Impact of Compass/Beidou-2 on future GNSS

Abstract The next decade promises drastic improvements to global navigation satellite systems. The USA is modernizing GPS, Russia is refreshing GLONASS, Europe is moving ahead with its own Galileo system, and The People's Republic of China is expanding its Beidou-1 system from a regional navigation system to a full constellation global navigation satellite system known as Compass/BeiDou-2, which consists of thirty five satellites including geostationary satellites, MEO satellites, and geosynchronous satellites in the coming year. Extra satellites will improve performance for all applications, and especially where satellite signals can be obscured, such as in urban canyons, under tree canopies, or in open-cut mines. The benefits of the expected extra satellites and their signals are increased availability, accuracy, continuity, and reliability. The advent of hybrid GNSS constellation has made the study of compatibility and interoperability increasingly important. A number of performance analyses have been conducted on a global scale with respect to availability, reliability, accuracy, and integrity in different simulated scenarios (such as open sky and urban canyons) for each system individually as well as for all possible combinations. Since the Compass/BeiDou-2 has received increasing attention from GNSS communities, the main objective of this study is to investigate the performance of Compass/BeiDou-2 in comparison with GPS, GLONASS, and Galileo in the greater Asia region; and also to explore whether combining Compass/BeiDou-2 with another GNSS would yield performance improvements in the region. Performance analysis can be conducted using either signals or geometrical conditions. However, the scope of this study is limited to the impact of current and future GNSS based on geometrical conditions. Therefore, the satellite visibility and DOP values of each system or their possible combinations are used as the major indices for the performance evaluation with an emphasis on the addition of Compass. In addition, those indices are analyzed in terms of their spatial and temporal distributions with an emphasis on the greater Asia region. Moreover, the spatial performance analyses are conducted as both global and regional scales to provide more insightful comparisons to illustrate the importance of Compass for users in the greater Asia region.