Q: Can RF interference to GNSS signals be generated by satellites in orbit? Has this occurred, and how can it be detected? - Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design
A: Unfortunately, uninterrupted use of GNSS navigation cannot be assured due to GNSS signal susceptibility to various disruptions. All GNSS systems rely on the ability to receive weak signals from thousands of kilometers away in space, making them vulnerable to Radio Frequency Interference (RFI). GN
Source: insidegnss.com