Flight Demonstration Results of an Inertial Measurement Unit and Global Positioning System Translator Telemetry System

The U.S. Army Research Laboratory (ARL) has been evaluating global positioning system (GPS) technology and strap-down inertial measurement units (IMUs) configured from inexpensive, miniature micro-electro-mechanical systems for the purposes of obtaining aerodynamics, trajectory reconstruction, and/or diagnostic information. A GPS translator from the Johns Hopkins University Applied Physics Laboratory and a low-cost IMU designed by ARL from commercial off-the-shelf components were combined with a telemetry system, packaged into a 2.75-inch HYDRA-70 rocket platform, and flight demonstrated. The onboard IMU sensors included accelerometers for measuring the thrust axis and lateral accelerations, angular rate sensors for measuring pitch and yaw rate, a dual axis magnetometer for roll rate and angular yawing motion, and sun-sensing optical sensors to provide a truth measurement for the rate sensor and magnetometer data. Hawk and Weibel tracking radars were also used as a truth measurement of the rocket's velocity and position for comparison to the acquired GPS data and integrated IMU accelerometer data. Results from comparisons of the IMU sensor data to the truth measurements suggest that reasonable aerodynamics and trajectory reconstruction can be achieved. The instrumentation system's development, calibration, demonstration, and the experimental results are described.Army Research Lab Aberdeen Proving Ground Weapons and Materials Research Directorate is the author of 'Flight Demonstration Results of an Inertial Measurement Unit and Global Positioning System Translator Telemetry System', published 2001 under ISBN 9781423525189 and ISBN 1423525183.