Francis Chun, USAF Academy, Department of Physics and Meteorology; Timothy Giblin, i2 Strategic Services, LLC; David Strong, Strong EO Imaging, Inc.; Benjamin Roth, USAF Academy, Department of Physics and Meteorology; Kyle Jones, Axient Corporation; Phillip Fishbein, Applied Optimization, Inc.; Anil Chaudhary, Applied Optimization, Inc.; Charles Wetterer, KBR, Inc.
Keywords: Falcon Telescope Network, Small Telescopes
Abstract:
Since the days of Sputnik, the Air Force has surveilled, tracked, and cataloged space objects primarily by ground-based radars and optical systems. Paradigm-shifting events such as the Chinese anti-satellite (ASAT) weapon test in 2007, the collision between an Iridium and Russian Cosmo satellite in 2009, India’s ASAT weapon test in 2019, and Russia’s recent ASAT test in April 2020, demonstrate the great need for more comprehensive space situational awareness (SSA). More so, commercial companies are becoming big investors in space capability, as demonstrated by SpaceX’s intent to create a 12,000+ constellation of low-earth orbiting satellites providing world-wide broadband internet service. It is estimated there will be more than 54,000 new satellites launched in the next decade by more than 90 nations and companies. The space catalog maintains tracks on less than 1 percent of the current objects in orbit. This has led to the recent creation of the latest military branch of service, the United States Space Force. Space situational awareness or space domain awareness (SDA) is, more than ever, an increasingly important mission to the Department of Defense and to the security of the United States. The next step beyond maintaining awareness of a satellite’s position is the ability to characterize them, and in general, the preferable method is to obtain a high-resolution image. However, high-resolution images from ground-based telescopes are only achievable if the satellite is large and close in range. Thus, small satellites in low-earth orbits and large satellites in geosynchronous orbits are essentially unresolved in the focal plane of a ground-based telescope. The unresolved signature problem could be overcome by building ever larger telescopes capable of tracking rates fast enough for satellites, but that requires tremendous resources and funding. Consequently, in 2011, the Department of Physics and Meteorology at the United States Air Force Academy was awarded a grant to develop a low-cost, commercially-purchased, network of small telescopes for the purpose of conducting education and research in non-resolvable space object identification (NRSOI). The Falcon Telescope Network (FTN) was born and now consists of 11 observatories across the world; six sites in Colorado, one in Pennsylvania, two in Australia, and one-each in Chile and Germany [1]. As we enter the second decade of operating the FTN, there is a need to upgrade and modernize it to keep up with the newest technology, increase the reliability of the system, and enable the latest observation techniques. The upgrades will help to increase the throughput of research in SSA/SDA, astronomy, and STEM outreach for future Air Force and Space Force cadets.
For the FTN upgrade program, we are essentially replacing everything except for the telescope or the optical tube assembly. The upgrades include a larger format CMOS camera, dual filter wheels, a direct-drive mount, an all-sky imager, and a redundant weather station. The dual filter wheels will have multi-spectral photometric filters (Kron-Cousin and Sloan Prime), hyper-spectral transmission gratings (100- and 200-lines per millimeter), and both linear and circular polarization filters. In addition to single filter measurements, the dual filter wheels will allow us to collect double filter measurements such as polarized spectra. We will present more details of the FTN upgrades and provide examples of the different image types and optical signatures that we can obtain for non-resolved satellite characterization. We will also present details of the image processing pipeline that was developed to process raw FTN imagery to final photometric, spectroscopic, and polarimetric signatures using the EOSSA data format [2-3]. Finally, the FTN upgrade program allows us the opportunity to look back on what has been achieved with the FTN over the past decade and look forward to what is planned using the upgraded network. We will highlight the opportunities afforded by having the individual components of the FTN upgrade designed to be identical, enabling research possibilities comparing and combining output from the network as a whole that can’t be achieved with the single sensor.
References
[1] Francis K. Chun et al 2018 PASP 130 095003
[2] Payne, T.E., S. Mutschler, N. Shine, D. Meiser, R. Crespo, E. Beecher, and L. Schmitt, “A Community Format for Electro-optical Space Situational Awareness (EOSSA) Data Products,” 2014 AMOS Conference Proceedings, Maui Economic Development Board, Hawaii, 2014.
[3] Payne, T.E., P.J. Castro, V.C. Frey, M.H. Ernst, C.R. Hufford, and T.J. Godar, “Enhanced Statndard Data Format for Reporting Electro-optical Data Products for Space Domain Awareness,” 2021 AMOS Conference Proceedings, Maui Economic Development Board, Hawaii, pp. 776-780, 2021.
Distribution A. Approved for public release: distribution unlimited. (PA #USAFA-DF-2024-199)
Disclaimer:
“The views expressed in this article, book, or presentation are those of the author and do not necessarily reflect the official policy or position of the United States Air Force Academy, the Air Force, the Department of Defense, or the U.S. Government.”
Date of Conference: September 17-20, 2024
Track: SDA Systems & Instrumentation