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Preliminary Lunar Surface SSA Architecture Optimization for the Observabilty of Cislunar and Lunar Resident Space Objects
No full textWith the extreme cost and rapid expansion of national, commercial, and international missions to cislunar space, proper tracking and conjunction-awareness by an efficient system is increasingly important. Although not the sole solution to cislunar space situational awareness (SSA), the lunar surface provides unique advantages to augment the observation of cislunar space. To prioritize efficiency, a framework is developed to create a heuristically optimized optical lunar-based SSA system. A sample implementation of this framework resulted in a system that is designed in response to Sun occlusion with a focus on three distinct cislunar regions of interest. This framework has provided a foundation to begin building more complex cost and sensor models to create lunar-based SSA systems of increasing fidelity and utility. A case-study implementation of this framework resulted in a system that was responsive to the environment that prioritized both overall coverage and consistency of coverage
Improving Military Medical Evacuation System Performance via Stochastic Optimization
Get PDFThis research highlights the importance of improving the performance of military medical evacuation systems to reduce the risk of permanent disability or death among service members in deployed environments. We employ a range of stochastic optimization techniques relating to integer programming, Markov decision process, approximate dynamic programming, and machine learning, as appropriate, to gain insights into factors that contribute to improving system performance
Preliminary Architecture Assessment of Lunar Surface Sensors for Cislunar SSA
Get PDFThe exploration of the lunar and cislunar realm is becoming increasingly active as several entities, private and public, foreign and domestic, set their sights beyond traditional Earth-centered space operations. Along with this renewed activity is a growing need for comprehensive Space Situational Awareness (SSA) and Space Traffic Management (STM) in the inherently chaotic cislunar system. This thesis seeks to embolden the study of cislunar SSA by considering the lunar-surface as a platform from which to conduct optical SSA. In this thesis, a lunar-based SSA system is heuristically optimized via a genetic algorithm through three separate implementations. All surface locations considered for sensor placement are derived from consideration of the lunar surface as a topological body, using NASA LOLA data and JAXA Kaguya stereo-imagery. The three implementations of the genetic algorithm optimize an SSA system based on stationary targets arranged in an equidistant set, an orbit family set and a combined equidistant and orbit family set. The results of this research show that a system comprised of small number of sensors with large fields of view is adequate to view specific out of plane orbits, but ultimately struggle to cover large swaths of the cislunar region. Any observation about the Earth-Moon equatorial plane will be greatly challenged both by the brightness of the Earth and the Sun. Although smaller sensor fields of view cover less area, they proved advantageous at avoiding exclusion zones. Additionally, the heuristic optimization of an SSA system in this fashion is responsive to the solar environment and can recognize and take advantage of obvious optimal placements even with a relatively simple algorithm
Analysis of Receiver Position and Velocity Uncertainty on Passive RF Cislunar SSA Architectures
No full textThis paper explores the utilization and analysis of a cislunar-based receiver to enhance a network of terrestrial and near-earth space-based passive RF receivers for conducting Space Situational Awareness (SSA) of objects in cislunar space. It models and explores the integration of a cislunar receiver into a network of terrestrial and GEO- based receivers. The added receivers are in various periodic, closed orbits around the Earth-Moon Lagrange points 1 , 2 , and 5 . The addition of the cislunar receiver is beneficial as the estimation accuracy of passive RF systems is based on the geometric orientation of the constituent emitter and receivers and a diverse geometric setup provides greater theoretical accuracy. The orientation’s usefulness for estimation is often measured through the metric of the dilution of precision (DOP). This research effort applies and adapts previous research into UAV-based passive RF estimation where receiver position and velocity uncertainty are considered and adapts/applies it to the problem of augmenting a terrestrial and near-earth passive RF architecture with a cislunar receiver. Provided is a derivation of the relationship between the receivers’ position and velocity uncertainties and relates that to the Cramer -Rao Lower Bound of the anticipated final estimation accuracy of the cislunar emitter
Propagation through and Characterization of Atmospheric and Oceanic Phenomena: Introduction to the Joint Feature Issue in \u3ci\u3eApplied Optics\u3c/i\u3e and \u3ci\u3eJournal of the Optical Society of America A\u3c/i\u3e
No full textThis joint feature issue in Applied Optics and JOSA A collects articles focused on the topic of propagation through and characterization of atmospheric oceanic phenomena. The papers cover a broad range of topics, many of which were addressed at the 2023 Propagation Through and Characterization of Atmospheric Oceanic Phenomena (pcAOP) Topical Meeting at the Optica Imaging Congress in Boston, Massachusetts, 14–17 August 2023. These papers are supplemented by numerous examples of the current state of research in the field. This is the first pcAOP feature issue, with the intention to produce an issue on this topic every two years
Training-informed Air Traffic Control Workforce Scheduling
No full textThe Radar Control Facility (RCF) at Eglin Air Force Base creates monthly workforce schedules. Adherence to regulations must be verified manually and no evaluation criteria exist to compare schedules. A mixed-integer program model for air traffic controllers allocates workers across 19 positions for a user-defined number of weeks of 24-hour operations. Across eight consecutive months, this model produced schedules to nearly eliminate all shifts with critical shortages from the reference schedules. Without civilian overtime work, gains in positional coverage require a 35% increase in overtime work for military workers and 35% reduction in monthly training instances. We recommend users adopt this generalizable model
Open-loop Wavefront Sensing in the Presence of Speckle and Weak Scintillation
Get PDFIn this paper, we show that speckle averaging helps to reduce the measurement error associated with a Shack–Hartmann wavefront sensor (SHWFS); however, this reduction is rendered ineffective with increasing beacon anisoplanatism. We do so operating in a weak-scintillation regime, where the SHWFS offers robust performance, and using in-plane translation of the illuminated rough surface to accomplish frame-to-frame speckle diversity. Understanding these trade-space limitations is critical when performing wavefront sensing with noncooperative, extended-source beacons
Real-time Synthesis of a Nonuniformly Correlated, Partially Coherent Beam using an Optical Coordinate Tansformation
Get PDFWe design, build, and validate an optical system for generating light beams with complex spatial coherence properties in real time. Beams of this type self-focus and are resistant to turbulence degradation, making them potentially useful in applications such as optical communications. We begin with a general theoretical analysis of our proposed design. Our approach starts by generating a Schell-model (uniformly correlated or shift-invariant) source by spatially filtering incoherent light. We then pass this light through an optical coordinate transformer, which converts the Schell-model source into a nonuniformly correlated field. After the general analysis, we discuss system engineering, including trade-offs among system parameters and expected performance. Finally, we test and validate the system by comparing experimental results to theoretical predictions. We conclude with a brief summary and a discussion of future work
