RFI Measurement Database Assembled During the Square Kilometre Array Site Qualification Campaigns

The Radio Astronomy and Remote Sensing communities are linked both formally and informally. The objective of this paper is to bring to the attention of the wider RF sensor remote sensing community some of the recent work undertaken while qualifying potential sites around the world for siting of the Square Kilometre Array (SKA). The construction of this SKA telescope is planned for some time after 2015, in a number of phases. At present, demonstrator systems are being assembled and tested at a number of locations around the world. Although remote sensing RF sensors are mostly directed from space to the earth, and the SKA candidate sites have been selected for radio quietness, it will be seen that SKA qualification measurements do provide a good assessment of the broad spectrum of radio frequency signals measured close to the surface of the earth, almost with global coverage. The SKA project adopted an approach of measuring average RF occupancy over a wide band (70 MHz to 26 GHz) and true RFI only in the L Band. The latter uses time domain sampling and FFT spectral analysis of the whole L Band.