Gyroscopic system for boresighting equipment by transferring a frame of

Abstract

Advanced boresight equipment and methods of using the same to effect a transfer of a two- or three-dimensional frame of reference from an ADL to a device to be boresighted. The equipment includes a stationary inertial sensor that is boresighted with respect to a reference line (such as the aircraft ADL). The stationary inertial sensor includes a first gyroscopic combination for generating a first output indicating a two- or three-dimensional frame of reference based on the ADL, and a docking station. The docking station facilitates alignment of a portable inertial sensor that also has a gyroscopic combination for generating a second output indicating its frame of reference. The portable inertial sensor may be identical to the first inertial sensor, or it may additionally include means for automatic optical operation including a gimbal and a gimbal drive system, an electromagnetic energy beam generator for projecting a beam, a second gyroscopic combination for generating a second output signal indicating a frame of reference, and a collimator for indicating an angle between two beams. The various methods of using both embodiments are also described. The invention provides unique calibration techniques, unique adapter and mirror sets, background electronic calibration, accommodation of personality modules, and a unique common mode stabilization technique to eliminate the effect of motion of the aircraft and the boresight technician, such as ship motion, wind loading, and earth rate. The use of the equipment includes the steps of boresighting the stationary inertial sensor with respect to the ADL reference line, positioning the portable inertial sensor in the docking station of the first inertial sensor for relative alignment relative thereto, processing the first and second outputs from the respective first inertial sensor and second inertial sensor to determine a difference between the respective frames of reference, aligning the portable second inertial sensor with respect to a device to be boresighted, reprocessing the first and second outputs from the respective first inertial sensor and second inertial sensor and determining a third frame of reference of the second portable inertial sensor relative to the first stationary inertial sensor, and translating the first, second and third frames of reference to thereby calculate the difference for alignment of the device with respect to the ADL reference line. The invention minimizes size, weight, and complexity of operation, and it reduces the alignment time associated with prior boresighting systems. There is no compromise of accuracy or of ruggedness for operation in adverse conditions.