Lightweight Compact Optical Correlator For Spacecraft Docking

摘要

Spacecraft docking, landing and star tracking are critical operations in various space missions. Docking provides the opportunity to joint two vehicles in order to change crews and deliver resources to a spacecraft. One of the main challenges in docking is to perform real-time tracking of the docking point for a precise and rapid feedback to the control system in order to achieve reliable operations. The same requirements are found for landing operations and star-tracking with main difference that the ground or sky is used for position and attitude tracking. Docking operations found multiple earth counterpart applications. Many of these earth-based applications concern the use of robotic devices to grab a specific object. In these cases various location parameters of the object are needed, such as rotation angle, scale and position. INO has developed a compact lightweight optical correlator prototype. This prototype provides a tool for the evaluation of various applications. In collaboration with ESA, INO studied the use of an optical correlator for selected space applications such as rendez-vous and docking, landing and star tracking operations. Optical correlator provides beyond real-time image processing capabilities and is well suited for target identification and positioning purpose. The optical correlator also shows low power consumption. In this paper, the latest analyses of the docking and landing applications are presented. For evaluation purpose, video sequences of Soyuz docking the International Space Station (ISS) were used. In the case of landing, moon images acquired in the SMART-1 mission, during its last orbits, were used. Mt. Wilson telescope images were used for star tracking examples.