Generic model for line of sight analysis and calibration

Many electrooptical (E/O) systems incorporate an imaging sensor and a Line of Sight (LOS) deflection mirror. At a higher system level, such as for fire control or missile homing applications, these sensors are required to measure angular target position very accurately. This work presents an approach that has been developed for the modeling and calibration of such electrooptical systems. Using a generic system which includes a mirror mounted on a two-axis LOS steering unit and an imaging sensor, a description of the mathematical model of the system is given here. This model may be used for system performance analyses as well as for developing various algorithms for the calculation of target angular position. The system model uses a number of calibration parameters such as gimbal nonorthogonality and other assembly and production errors. These are obtained from laboratory measurement results via a mathematical calibration model. We explain how the calibration model is developed from the system model. The method shown here can significantly reduce the number of computations and the look-up-table capacity needed in an operational system, as well as reducing the extent of laboratory calibrations usually required.