Analyses show that astronomical occultation methods may be used to determine the silhouettes of satellites at geostationary distances, a result few other techniques can achieve. Specifically, an array of photon-counting detectors is positioned in the path of the target shadow from one star. Reduction of the received star intensity vs. time can yield silhouette resolution of less than a meter. In this paper, we address the critical issues of a) the limited density of useable stars, b) positioning of the detector array into the path of the shadow, and c) undoing the effects of diffraction. A conceptual design for an imaging station is presented.
Beginning with the launch of Sputnik in 1957, the United States Air Force has actively pursued the development and application of optical sensor technology for the detection, tracking, and monitoring of artificial satellites. Until the mid-1980s, these activities were conducted within various Air Force Research and development agencies which supplied data to the operational components on a 'contributing' basis. This paper traces the early evolution of the optical space surveillance technologies from the experimental sensors into the current operationally deployed systems. The contributions of the participating organizations and facilities is reviewed with special emphasis on the development of techniques for the identification and monitoring of spacecraft using optical imagery and signatures.
The Air Force Maui Optical Station (AMOS) has demonstrated follow-up astrometry and photometry for near-earth objects (NEOs), with results published in the Minor Planet Circulars. Although this information is important for the cataloging of all NEOs, it does not provide all of the data needed to assess the potential hazard posed by these objects, i.e. composition, size, shape, and dynamics. AMOS has increased its capability by adding a six position filter wheel (in conjunction with Phillip's Laboratory's Geophysics Directorate and the University of Arizona), for use on the Jet Propulsion Laboratory's CCD camera mounted on the AMOS 1.2 meter telescope. The paper provides the rationale for three-color photometry for determination of NEO characteristics, as well as preliminary results of the observations of several NEOs an main-belt asteroids. It also discusses the design of a photo-polarimeter, to be built in the near future, which will add more capability to AMOS, and determination of albedo and size of NEOs of particular interest to both the scientific and government communities.
To better characterize the orbital debris environment, improvements must be made to the overall sensitivity of the orbital debris surveillance system. There are many ways to improve the sensitivity of the optical system: through hardware and software improvements, and through observing techniques. AMOS has been investigating algorithms for processing video data as a technique for improving the sensitivity of the optical sensors. This paper discusses preliminary results for two different approaches to the sensitivity issue, and the potential for implementing them in real time.
The Air Force Maui Optical Station (AMOS) conducted searches, measurements, and analyses of the orbital debris environment for the Air Force Space Command and the Phillips Laboratory since May 1991 in support of the Air Force Orbital Debris Measurements Program. The objective of this program was to detect orbiting low earth objects not currently in the United States Space Command Space Surveillance Center catalog. Once objects were detected, further objectives were to track, catalog, and maintain those objects locally, to determine statistics on detected objects, and perform relevant analyses. AMOS has developed a prototype surveillance system for the detection and tracking of orbital debris. In addition to this surveillance activity, AMOS has also automated the post-processing videotape streak detection process and is automating the analysis process. Both the optical tracking of orbital debris and the automatic streak detection process were thought to be virtually impossible only a few years ago. The AMOS program employed wide field of view optical telescopes using the Maui Groundbased Electro-Optical Deep Space Surveillance site and AMOS narrow field of view tracking telescopes, both located at the Maui Space Surveillance Site.
The Air Force Phillips Laboratory (PL) is tasked by Air Force Space Command to characterize the orbital debris environment. Part of this task is to search for and detect debris using the optical facilities at the PL Air Force Maui Optical Station (AMOS), which is located at the Maui Space Surveillance Site (MSSS). The goals of the program are discussed, with emphasis on the detection program. This includes telescopes and sensors available, how they are used, and handoffs from one sensor to another. Results of this correlation, as well as conclusions on the orbital debris environment, are presented.
The Air Force Phillips Laboratory is conducting measurements to characterize the orbital debris environment using wide-field optical systems located at the Air Force's Maui, Hawaii, Space Surveillance Site. Conversion of the observed visible brightnesses of detected debris objects to physical sizes require knowledge of the albedo (reflectivity). A thermal model for small debris objects has been developed and is used to calculate albedos from simultaneous visible and thermal infrared observations of catalogued debris objects. The model and initial results will be discussed.