Objectives The polar region is a globally critical area, and its environmental monitoring is vital for climate change research. Given the unique application potential of the BeiDou-3 satellite navigation system (BDS-3) reflectometry (BDS-3-R) technology for polar observation, we aim to systematically evaluate and quantify its spatiotemporal observation performance under various orbital configurations to guide future mission planning.

Methods We take BDS-3 satellites of multiple orbit types as the research objects and conduct a detailed analysis of a 10 d BDS-3-R polar observation simulation event. Based on this analysis, we innovatively propose a new set of spatiotemporal observation performance evaluation methods. Focusing on two core parameters of satellite orbital altitude and orbital inclination, we deeply investigate their influence mechanisms on the polar coverage capability and revisit characteristics of BDS-3-R.

Results The simulation results reveal a close relationship between the spatiotemporal performance in the polar region (latitudes above 66.34°) and the orbital parameters. As the satellite orbital altitude increases, while the observation range may expand, the revisit period correspondingly lengthens, and the spatial resolution significantly decreases. Quantitative analysis shows that at a typical orbital altitude of 800 km, the revisit period is approximately 35 hours, with an average spatial resolution of about 17.6 km. Notably, high-orbit geostationary Earth orbit (GEO) satellites were found to be conducive to generating grazing angle observation events in the polar region. Regarding orbital inclination, the revisit period gradually lengthens as the inclination approaches 90°. More critically, when the inclination is set below 80° or above 100°, the BDS-3-R observations produce distinct monitoring blind zones in the central Arctic and Antarctic regions. Furthermore, the analysis indicates that polar observation missions tend to adopt a larger reflector antenna tilt angle, and the pointing azimuth has a significant regulatory effect on the number of obtainable reflection events.

Conclusions The performance evaluation framework and the quantitative results obtained in this study successfully reveal the optimal orbital configuration for the BDS-3-R system in the polar environment. The study recommends a dual-satellite networking approach with inclinations of 70°,80° and 80°,90° for comprehensive polar coverage observation, providing an important theoretical basis and technical support for the orbital design, satellite configuration, and mission planning of future GNSS-R-based polar exploration missions.