Two-dimensional spatial spectrum estimation direction finding method at subarray level

There is a great practicality in applying spatial spectrum estimation direction finding method to large arrays where only subarray outputs are digitized, such as multi-function phased array radar. The proposed spatial spectrum estimation direction finding methods need the complete array manifold. But it is difficult to obtain the whole array manifold for large phased array at subarray level, the above methods is hardly to be applied. For this case we construct a space array manifold and present a two-dimensional spatial spectrum estimation direction finding method for the array at subarray level. The basic idea is to treat each subarray as a 'super-array element', subarray centers as phase centers of 'super-array elements' and subarray combined gains as gains of 'super-array elements'. And we only use the phase centers and gain of each subarray in practice. Therefore it is no essential to know the complete array manifold and to calibrate the whole array. And it is suitable for the arbitrary plane arrays. The simulation results demonstrate the efficiency of the method.