Design of a Space-Borne Autonomous Infrared Tracking System

<p>Complete characterization of the space environment in support of the United States' goal of Space Situational Awareness is not currently achievable. When confronted with recent increases in the deployment and miniaturization of microsatellites by numerous nations the questions of foreign space capabilities are magnified. This study sought to determine the feasibility of and experimentally demonstrate a microsatellite capability to autonomously loiter about and track a target satellite. Various methods of passive remote sensing were investigated to determine the best means of detecting and tracking a target in space. Microbolometer-based infrared sensors were identified as the best sensor for several reasons primarily due to their ability to track in the absence of light. A representative system was constructed for demonstration in AFIT's SIMSAT laboratory. Software modeling results identified open-loop instability and therefore the requirement for closed-loop control. A simple PD control algorithm served as the basis for control and a pseudo-feed-forward term was added to improve the results. The feed-forward term was derived form orbital dynamics as the rate at which the chase satellite traverses around an ellipse formed in the target's frame of reference. Reduction in pointing errors of up to 67% were found in simulations. Non-optimal yet successful tracking results were obtained in the laboratory with a hardware-in-the-loop model for both step and moving inputs. With minor modification this infrared tracking system could be implemented onboard a microsatellite.</p><p>This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact and remains as true to the original work as possible. Therefore you will see the original copyright references library stamps (as most of these works have been housed in our most important libraries around the world) and other notations in the work.</p><p>This work is in the public domain in the United States of America and possibly other nations. Within the United States you may freely copy and distribute this work as no entity (individual or corporate) has a copyright on the body of the work.</p><p>As a reproduction of a historical artifact this work may contain missing or blurred pages poor pictures errant marks etc. Scholars believe and we concur that this work is important enough to be preserved reproduced and made generally available to the public. We appreciate your support of the preservation process and thank you for being an important part of keeping this knowledge alive and relevant.</p><br>