Monopulse Phased Array Radar Channel Uncertainty Calibration

Inconsistency between the sum and difference channels in the phased array radar system will affect angle measurement accuracy if the monopulse angle measurement technique is employed. In order to achieve better angle measurement accuracy, they need to be calibrated. The calibrating technology is mainly divided into two groups: the off-line ones and the on-line ones. The former one is now widely used in the monopulse system to calibrate the amplitude and phase imbalances between the sum and difference channels by injecting test signals. Because we can have a full knowledge of the input signal, the conception and realization of this idea is not too complicated. Chapter Four is focused on this and it gives us a very detailed introduction to the calibrating idea and algorithm realizations. It also introduces the calibrating performances by using three different off-line calibrating algorithms along with the simulation results. The deficiencies of the off-line methods are as follows: it is not an adaptive method so it cannot change when the system parameter changes; it is, to some degree, depend on the form of the injecting signal. Owing to the complexity of the on-line methods and the diversity of the form of radar echo wave, there aren't many people who have paid much attention to this question of on-line calibrating. But along with the development of nonlinear regression and system identification, on-line detection and calibrating gained their former attention. Chapter Five in details introduces the on-line calibrating idea and method based on nonlinear regression and system identification. It also analyses the performance characteristics of this methods under two different error systems while at last gives us the simulation results. Finally, a summary is given.