Coverage restricted to an angle

Given a set S of n antennas and point q on the plane, q is α-covered by S if ∃si,sj∈S such that the angle ∡(si,q,sj)≥α. It is shown how to minimise the transmission range of S to α-cover a point in O(n) time and space, and how to construct the π2-covered region in O(nlogn) time and O(n) space. Finally, this paper introduces the Coverage Voronoi diagram and an algorithm to construct it in O(n4logn) time.