Assessment of real-time and backup GNSS orbit, clock, attitude, and biases products from CNES/Nav

To ensure reliability and accuracy in the Global Navigation Satellite Systems (GNSS) real-time data streams, maintenance operations may be performed at the server side, which could temporarily interrupt the availability of the real-time products for users. To address these issues, backup products were introduced by Centre National d’Etudes Spatiales Navigation Team (CNES/Nav) in November 2022. During maintenance periods in nominal real-time services, CNES/Nav switch to backup data stream, ensuring continuous products to real-time Precise Point Positioning (PPP). However, only a few studies have analyzed the backup products, and their application in the PPP with ambiguity resolution (AR) has not been investigated. In this research, the consistency of orbit, clock and bias products of real-time and backup products provided by CNES/Nav were assessed over 1 year. In addition, characteristic of yaw attitude behavior with two different products was also presented in the eclipse seasons. Moreover, static and kinematic multi-frequency PPP-AR was conducted to further verify the quality of real-time and backup products. Taking the Wuhan University (WUM) final products as the reference, the results demonstrated that orbit, clock and bias of backup products exhibited better consistency than these of nominal real-time products. For multi-frequency PPP-AR solutions, after convergence, the 3D Root Mean Square (RMS) of static and kinematic solutions were 1.2 and 2.8 cm with backup products, respectively, position performance mostly agreed well by using two products. Therefore, backup data stream could serve as reliable substitute when nominal real-time data stream during maintenance operations.