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Abstract

As a complementary alternative to GPS, the independent BDS-3 technology is of interest for low-cost space missions due to its global service. In this study, we assess the single-frequency real-time orbit determination accuracy using BDS-3-only and test the orbit determination algorithm with actual fight data of new frequencies of B1C and B2a from the Haiyang-2D satellite of China. Compared with the B1C frequency, the accuracy of the B2a code can be effectively improved due to a 10-time higher chipping rate, which makes the combined measurements of the code and the carrier phase to be better than 2 cm. Additionally, the B2a measurements exhibit good performance in terms of the availability and the antenna hemisphere's coverage, which reduce the differences between vertical and horizontal dilution of precision by 70%. Preliminary orbit determination results show that the solutions of the B2a frequency with three-dimensional position and velocity errors of 32 cm and 0.30 mm/s are achieved, and the position errors in the along-track, cross-track, and radial components are improved by 26.3%, 18.8%, and 18.2%, respectively, compared with the B1C. Overall, the achieved performance of the BDS-3 is expected to meet the needs of onboard position knowledge for many low-cost satellites.