A system comprising: a radar field unit configured to be supported by a structure that partially blocks the angle of view including: - an antenna comprising a plurality of antenna elements disposed azimuthally around the field unit to provide a substantially continuous coverage area, that does not include the structure, in the azimuthal plane, the antenna elements being arranged in an array in azimuth and elevation axes, the antenna being a phased array antenna wherein the radiation from the antenna may be steered both in azimuth and elevation; and - at least one beam control element positioned along the perimeter of the antenna at a first azimuth angle relative to the main lobe axis of the antenna to exclude the structure from the radiation field of the antenna array such that reflections from the structure received by the antenna are reduced, the beam control element including a reflective material and an absorptive material positioned between the antenna and the reflective material configured to attenuate radiation approaching the antenna from the structure and radiation emitted by the antenna toward the structure. a radar field unit configured to be supported by a structure that partially blocks the angle of view including: - an antenna comprising a plurality of antenna elements disposed azimuthally around the field unit to provide a substantially continuous coverage area, that does not include the structure, in the azimuthal plane, the antenna elements being arranged in an array in azimuth and elevation axes, the antenna being a phased array antenna wherein the radiation from the antenna may be steered both in azimuth and elevation; and - at least one beam control element positioned along the perimeter of the antenna at a first azimuth angle relative to the main lobe axis of the antenna to exclude the structure from the radiation field of the antenna array such that reflections from the structure received by the antenna are reduced, the beam control element including a reflective material and an absorptive material positioned between the antenna and the reflective material configured to attenuate radiation approaching the antenna from the structure and radiation emitted by the antenna toward the structure. - an antenna comprising a plurality of antenna elements disposed azimuthally around the field unit to provide a substantially continuous coverage area, that does not include the structure, in the azimuthal plane, the antenna elements being arranged in an array in azimuth and elevation axes, the antenna being a phased array antenna wherein the radiation from the antenna may be steered both in azimuth and elevation; and - at least one beam control element positioned along the perimeter of the antenna at a first azimuth angle relative to the main lobe axis of the antenna to exclude the structure from the radiation field of the antenna array such that reflections from the structure received by the antenna are reduced, the beam control element including a reflective material and an absorptive material positioned between the antenna and the reflective material configured to attenuate radiation approaching the antenna from the structure and radiation emitted by the antenna toward the structure.