The International Telecommunication Union (ITU) provides the international regulatory framework that governs the uses of the radio spectrum that the SKA will cover. The primary instrument used by the ITU to accomplish its task is the Radio Regulations (RR), an international treaty. Below the RR in hierarchy, but still at an important level, are the set of ITU-R Recommendations. For radio astronomy, the most important is Recommendation ITU-R RA.769, which lists the thresholds levels of interference harmful (or, in ITU-speak, detrimental) to observations in various bands allocated to radio astronomy. At a still lower level in this hierarchy are ITU Reports and the Rules of Procedure (ROPs), an interpretation of the Radio Regulations internal to the ITU that allows it to proceed with practical work.
I examine what provisions of the Radio Regulations cover radio astronomy, and how they may be applied to the SKA. I then discuss how the set of ITU-R radio astronomy recommendations, in particular Recommendation ITU-R RA.769, could be modified to cover the SKA. I discuss some of the assumptions that go into the calculation of threshold levels in and how they may change under the SKA scenarios envisioned.