Abstract: Methods and apparatus for a radar system having an array including a series of concentric rings of array elements, wherein the concentric rings that have a shape defined by respective ellipses that increase in size from a center that is common to the respective ellipses. The series of concentric rings can include multiple groups of the concentric rings, wherein the concentric rings in each successive group are larger in size than the concentric rings in the first group.

Abstract: Described herein is an apparatus and a method for an antenna array calibration device and method. The device comprises a radio frequency/optical (RF/optical) data center having at least one optical input/output; N single mode fibers (SMF) each having a proximal end connected to the at least one optical input/output of the RF/optical data center and a distal end, where N is a positive integer; N optical/RF dish calibrators each having an optical input/output connected to the distal end of the at least one SMF input/output; N coaxial transmission lines each having a proximal end connected to one of the RF input/output of the N optical/RF dish calibrators and a distal end; and N dish antennas each connected to the distal end of one of the N coaxial transmission lines.

Abstract: Methods and apparatus to calibrate an array by sequentially calibrating elements in a subarray with respect to each other using a satellite. The satellite is repeatedly illuminated for calibrating the elements using reference elements to determine plane fronts from which active elements can be calibrated with respect to each other.

Abstract: Methods and apparatus to calibrate an array by sequentially calibrating elements in a subarray with respect to each other using a satellite. The satellite is repeatedly illuminated for calibrating the elements using reference elements to determine plane fronts from which active elements can be calibrated with respect to each other.