Determination, control and improvement of an SKA radio environment in South Africa
NeŽl Smuts (South Africa) neelsmuts@icon.co.za

South Africa, in its bid to host the SKA, has adopted a dual approach to determine, assess and improve the radio environment and RFI that would be experienced by the SKA. The one approach was to determine all the transmissions that would provide signals which exceed the various threshold levels, including the saturation level, by means of computerised signal level calculations and the establishment of a database which could be used for assessment and analysis. The other was to carry out RFI measurements at the sites according to the RFI Measurement Protocol. This paper aims to provide a review of the data collection and the computerised signal calculation process. At the same time it was realised that the regulatory position would be a key issue and required attention.

The method used to create the database for transmissions in the frequency band from 150 MHz to 25 GHz which would affect the SKA will be described as well as its limitations and the process used to carry out calculations to predict signal levels. The telecommunications and broadcasting signal distribution network operators were involved in this process. The saturation level and the radio astronomy threshold levels are included in the database. Possible improvements to the radio environment are receiving attention.

As the telecommunications and broadcasting regulatory framework will play a key role in the control and improvement of the radio environment, an analysis of the existing regulatory framework in the context of the SKA was done considering the SKA science requirements, ITU Recommendations and Resolutions and South African legal provisions. An overview of this process will be provided.

A summary will be provided of the results obtained, the analyses carried out and the conclusions made. Analyses made include factors such as signal level graphs, number of signals involved and spectrum occupancy.