Optimum number of faces of a volume-scanning active array radar

The problem of finding the optimal number of phased array faces for performing hemispheric volume surveillance is considered. Assuming the detection performance is the same in all beam positions and the total number of modules are constant, it is shown that the optimal number of array faces is three. This is true when coverage extends to the zenith and to 45/spl deg/ elevation. It is also true whether the array faces are operating simultaneously or sequentially.