The purpose of the meeting was to revise pre-selected parts of the ITU Radio regulations which form the basis of planned international usage of the radio spectrum. Several of the agenda items for the meeting involved radio astronomy. For the first time since 1979 this would enable radio astronomy to improve its allocations in this range in order to protect the greatly increased radio astronomy usage of the band. We have already reported on the radio astronomy preparations for the meeting, and the development of a set of allocation proposals for which widespread approval had been obtained before WRC-2000 began. The new radio astronomy allocations for 71-275 GHz.
Unfilled blocks represent secondary allocations.
WRC-2000, with about 2,500 attendees, has now come and gone, and we are happy to report that the astronomers' careful preparations have been well and truly rewarded. More than a dozen radio astronomers participated in the meeting and carefully nursed the proposals through the various committees which had to approve them. Even extra protection proposed only by Asia-Pacific countries for some spectral lines not covered by the allocations was approved. The line profile shows the variation of zenith atmospheric attenuation with frequency. The new radio astronomy allocations now extend across most of the windows, and for the central window in particular, the improved protection is enormous.