Abstract:The frequency band 8025-8400 MHz is extensively used by a large number of sounding data transmission systems of the FY-3 series non-GSO meteorological satellites with earth exploration-satellite service on a primary basis. Many other services and systems operate in the same frequency band. Finding a way to avoid harmful interference and ensure the sharing and compatibility between FY-3 systems and other incumbent systems is significant. At present, the domestic sharing and compatibility studies in this frequency band are not based on the accurate characteristics of the actual meteorological satellites systems, resulting in potential risks of negative effects on the application and delicacy management of the spectrum. Based on the parameters of the data link used by FY-3 satellites, this paper conducts the study and provides the aggregate and single-entry protection criteria and coordination threshold from space and ground directions respectively, which can be directly applied to coordination meetings between FY-3 series and other satellite networks at the national or international level.