Feature Identification from Unresolved Electro-optical Data

ABSTRACT: As the number of objects in orbit about the Earth and the capabilities of satellites increase, it becomes more difficult to obtain true space situational awareness (SSA). In many cases, the small size or distance of these resident space objects (RSOs) further complicate this problem because it is beyond the capability of ground-based electro-optical sensors to resolve them. For that reason, novel ways to use time-resolved radiometric, photometric, and polarimetric measurements to estimate relevant characteristics of these RSOs are vital to SSA and protecting our assets in space. To that end, Emergent Space Technologies, Inc. and the University of Texas at Austin propose using Hierarchical Mixtures of Experts (HMEs) to process electro-optical measurements, including apparent magnitude, declination, and right ascension, in order to estimate the size, shape, configuration, attitude, angular velocity, and reflectivity of resident space objects. BENEFIT: Our goal is to increase the utility of unresolved electro-optical measurement data in estimating important characteristics of RSOs. Using the models and algorithms developed in Phase 1, we can estimate the size, shape, configuration, attitude, angular velocity, and attitude of an RSO. This improves SSA because the function and intent of an RSO is more easily inferred when these estimates are available. In Phase 2 we will develop and validate an operational prototype of our system and demonstrate it in the AFRL JMS Test Bed. A validated and tested feature identification system could be used not only by the JMS but by any commercial or government organization that uses optical observations of space objects to estimate their attitude or material properties. The HME could have commercial applications for collaborative GPS tracking applications in which multiple, distributed GPS sensors are operating in degraded environments. The HME may also provide an ability to accomplish integrity monitoring of GPS satellite systems for applications that are life critical and require the highest levels of navigation accuracy, such as in automated precision landing systems. This technology is also applicable to medical imaging, meteorology, and homeland security applications.