Abstract: A detector beamformer array system having a sparse array and a reference ay. The reference array is adapted, according to known principles, to have an output response with one main lobe significantly larger than all other side lobes, and with a substantially flat response. Signals received by both arrays are cross-correlated with one another, and only signals sufficiently correlated are annunciated. The resulting adaptive array system has a resolution even better than that of the sparse array's aperture, and with directional sector selectivity corresponding to the angular width of the reference array's mainlobe, providing a system having high resolution and directional selectivity, but with far fewer sensors than with filled arrays used for this purpose.

Abstract: A method of nulling out interference sources in a large-aperture phased ay radar system is described. The system has apriori knowledge of the interference sources and depends upon access to the array element phase shifters for injection of phase only or phase and amplitude perturbations, of a mainbeam aperture distribution, into said array element phase shifters. The phase or phase and amplitude perturbations are derived from an aperture ripple modulation algorithm. The system does not require any auxiliary elements or correlators or beamformers.A method of nulling out interference sources in a monopulse large-aperture phased array radar system is also described wherein the phase only or phase and amplitude perturbations are injected into both the sum and difference beams.

Abstract: A partially adaptive array which compensates for jamming. The array is comprised of more than 1000 elements and uses a bootlace lens to form a family of beams from which an adaptive array chooses at least one beam of the family of beams that most closely represents the jamming, and subtracts the beam from a main beam. In this way jamming of the beam is compensated for.