Study of a Strong L-Band RFI Source

• Main Authors: Paolo de Matthaeis, David M. LeVine, Yan Soldo, Alvaro Llorente
• Format: Article
• Language: English
• Published: IEEE 2021-01-01
• Series: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
• Subjects: L-Band; microwave radiometer; radio frequency interference (RFI)
• Online Access: https://ieeexplore.ieee.org/document/9511806/

CN006 is the name given by the European Space Agency (ESA) in their reports on radio frequency interference (RFI) to an instance of RFI in the L-band spectral window at 1.413 GHz protected for passive use only. The source of the interference is located east of the Chinese city of Hangzhou in an area with radar installations. Its effect was initially indistinguishable from that of many such RFI sources observed by the ESA's SMOS and NASA's Soil Moisture Active Passive (SMAP) radiometers over China. However, in July 2020, the level of radiation increased dramatically reaching levels exceeding 1700000 K as reported by Soil Moisture and Ocean Salinity (SMOS) becoming the strongest source observed by SMOS. This article describes an analysis of this very strong source (a radar). It provides information to provide insight into an example of a well-defined source of RFI and illustrates the powerful capability of the SMAP radiometer receiver and RFI processing incorporated in it for identifying and understanding interference.