Ground-based optical detection of deep space nuclear detonations

Simple approximate expressions are developed to describe the ring of fluorescent light from X rays impinging on the atmosphere. The relative ranging capability of zenith-oriented detectors is then estimated as a function of effective collecting area, field of view, electronic bandwidth, burst angle, and atmospheric pulse broadening. Narrow fields of view comparable in width to the fluorescent ring are shown to afford greater ranging capability than wide ones for all events more than 10° above local horizon, even under hazy conditions; however, the advantage is at most a factor of two. Both photomultiplier and solid-state detectors are treated. Some consideration is given to the performance of a multistation network, each station of which uses a solid-state detector array fed by a large collecting mirror. Triangulation out to 10 4 or 10 5 km appears feasible and would allow an approximate determination of yield.