Standard for Remote Sensing Frequency Band Radio Frequency Interference (RFI) Impact Assessment

Radio Frequency Interference (RFI) originating either from radiocommunication services in nearby frequency bands or from sources transmitting illegally or above permissible power limits is affecting spaceborne passive and active microwave Earth Observation instruments. 

Microwave (MW) sounders are designed to measure the total amount of radiative power in the form of brightness temperature. A 230 K natural occurring signal that also has a 5 K anthropogenic sourced signal would be measured by the MW sounder as a 235 K brightness temperature.  Similarly, a 235 K naturally occurring signal without any added anthropogenic sourced signals would also be measured as 235 K.  The two scenarios are indistinguishable from each other in current MW sounders.  Similar issues are expected with other types of remote active and passive band sensors.  Efforts are underway to develop methods and technologies that may reduce the risk of data corruption and loss.

This non-natural radio frequency (RF) contamination will only continue to increase in intensity and number.  This growth has been observed by the spectrum management community for decades.  Information is needed for spectrum managers to allocate the efforts to enforce radio-regulations, for space agencies to protect the remote sensing instruments that will provide more benefit to society, and/or to allocate efforts in RFI mitigation techniques, and for researchers to understand the errors associated with their retrievals.

The IEEE Geoscience and Remote Sensing Society/Standards Committee (GRSS/SC) has initiated a standard development process to address the concerns for RFI caused degradation to remote active and passive sensors. This standard will provide a standard for RFI assessment of the affected frequency bands.