DIRECTED ENERGY SYSTEM POINTING THROUGH GEOSYNCRONOUS POSITIONING SATELLITE INTERFEROMETRY

CURRENT STUDIES CONCENTRATE ON GLOBAL POSITIONING SYSTEM (GPS) AS A SPACECRAFT ATTITUDE DETERMINATION TOOL. TWO GPS ANTENNAS RECEIVING THE SAME SIGNAL CAN COMPARE THEIR RELATIVE PHASES TO DETERMINE THE ANGLE BETWEEN THE TWO ANTENNAS AND THE GPS SATELLITE. BY COMPUTING THE ANGLE TO THREE OR MORE SATELLITES, THE COMPLETE INERTIAL ORIENTATION MAY BE DETERMINED. APPLYING ADVANCES IN GPS INTERFEROMETRY TO PRECISION POINTING OF DIRECTED ENERGY SYSTEMS LOCATED IN SPACECRAFT IS BEING INVESTIGATED. BY MEASURING THE ORIENTATION OF THE LASER ITSELF, MANY ERROR SOURCES SUCH AS GYROS, STAR TRACKERS, HORIZON SENSORS, GIMBAL PICK-OFFS, DEPLOYMENT MISALIGNMENT, AND STRUCTURAL BENDING MAY BE ELIMINATED OR REDUCED. THE RESULTING IMPROVEMENT IN POINTING ACCURACY DIRECTLY IMPROVES THE CHANCES OF HITTING AND DESTROYING THE TARGET, AND THUS IMPROVES THE UTILITY OF SPACE-BASED BALLISTIC MISSILE DEFENSE SYSTEMS. THE STUDY INCLUDES CONCEPT DEVELOPMENT, ERROR BUDGETING, AND TRADE-OFF ANALYSIS.