Computer modeling of jamming effects on infrared missiles

Abstract

Development of effective countermeasures for use against infrared (IR) missiles is hindered by the difficulty inherent in testing tactical missiles. The designers of such a countermeasure must devise a means of reproducing missile attitude after the test flight to allow for further analysis. This thesis describes an Inertial Measurement Unit (IMU) compact enough to be mounted on board a 4.5 inch missile. The IMU sensing elements are three quartz rate sensors providing yaw, pitch and roll rates, arid the functionality of a gyro-stabilized system without the extensive electronics and high-speed spinning rotor. These micro-miniature, solid state devices are durable and compact; yet robust enough to allow for the precise recreation of missile attitude. A Simulink model is presented that accepts missile strap-down angular rates and, using an Euler rotation technique, produces yaw, pitch, and roll angles in an earth reference. The model corrects for sensor cross coupling, bias, and other factors. It has been calibrated using Carco Table test data, producing angles that matched expected values to within 2 degrees RMS on each axis. The resulting highly accurate attitude profile is stored as angle data and can also be viewed via an animation utility.