Dissertations / Theses: 'Navigation (Aeronautics)'

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pozzobon, oscar. "Satellite Navigation Authentication and applications in Aeronautics." Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3426197.

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GNSS is becoming a fundamental mean of navigation for aviation, unmanned aircraft including drones and rockets. Although integrity of the system has been planned and designed since the 70s, little few work have been performed in the domain of security related to satellite navigation systems and aviation. The emerging threats refers to mainly intentional interferences such as jamming and spoofing. Today in an aircraft cockpit there is a number of technologies that rely on Global Satellite Navigation Systems (GNSS), from flight management to Timing, Navigation and anti-collision to Auto pilot functions. The increasing use of GNSS in the flight management and auto pilot systems and its benefits both for navigation and surveillances are the baseline to design protection and alerting systems for GNSS. This thesis begins with an introduction and review of use of GNSS in aeronautics with a particular focus in aviation. A number of critical avionics components are identified and potential risk and security issues are identified and discussed. A generalized theoretical threat model is defined which can be used as a starting point for risk assessment and analysis of vulnerabilities of GNSS. Attacks are categorized in different sophistication that can be used by risk planners to model the security requirements and probability of risk. The work continues with a theoretical background of GNSS authentication, to introduce the philosophical aspects of GNSS authentication design. Three postulates are announced and explained, which have the objectives to provide an instrument for verification of correct authentication protocol design and verification. The work analyzes two main possibilities for protecting the radio navigation in aeronautics: Aircraft protections, which include protections in the GNSS receiver or integration with other equipment in order to verify and mitigate any attacks, and GNSS System protections, which discusses authentication services that can be implemented in the ground or space component of GNSS. Details and results of all different techniques are presented and discussed for every group of technique presented. A final concluding chapter analyzes the pros and cons of the different techniques and attempts to perform an example of how risk assessment can be performed by government or service providers using as input the safety requirements and comparing them with the different attacks and protection techniques. The work concludes with directions and guidelines for future work.
I sistemi di navigazione satellitare stanno diventando un mezzo fondamentale di navigazione per l’aviazione ed aeronautica e la navigazione senza pilota, incluso droni e razzi. Sebbene l’integrità sia stata studiata ed implementata dagli anni 70, poco è stato fatto per discutere la sicurezza degli stessi nel settore dell’aviazione. I pericoli ed attachi che stanno emergendo sono in particolare interferenze di jamming e spoofing. Ad oggi nelle cabine pilota dei moderni aerei vi sono installate un gran numero di tecnologie che si basano sui sistemi di navigazione satellitare (GNSS), dalla gestione del volo al tempo, alla navigazione ed anti-collisione, alle funzioni di auto pilota. L’uso sempre più commune del GNSS nei sistemi di gestione del volo e gli autopilota ed I benefici per sia la navigazione che la sorveglianza sono le basi per il design dei sistemi di protezione ed alert del GNSS. La tesi inizia con una review ed introudzione al GNSS ed aeronautica con particolare focus all’aviazione civile. Gli elementi critici dell’avionica ed i potenziali rischi e limiti di sicurezza sono identificati e discussi. Un modello teorico generale è presentato e discusso ed usato come base per le discussioni sulla valutazione del rischio e dell’analisi vulnerabilità del GNSS. Gli attacchi sono categorizzati con diversi livelli di sofisticazione e possono essere usati per pianificare e modellare il rischio Il lavoro continua con introduzione al background della autenticazione GNSS ed introduce aspetti teorici dell’autenticazione. Tre postulati sono enunciati e spiegati, con l’obiettivo di dare uno strumento per la corretta definizione e progettazione degli schemi di autenticazione. Il lavoro analizza due maggiori possibilità per introdurre sicurezza nel settore dell’aviazione: protezione a livello dell’aereo e quindi dei sistemi avionici e protezione a livello sistema GNSS. Un numero di tecniche per la protezione a livello aereo e a livello GNSS sono presentate e per le quali sono state effettuate diverse sperimentaizoni e simulazioni. I risultati vengono presentati e discussi nelle varie sottosezioni e per ogni gruppo di tecniche presentate. Un capitolo in conclusione confronta le varie tecniche e cerca di fornire uno strumento su cui fare del risk assessment e come baseline per la definizione dei requisiti. Il lavoro conclude con conclusioni generali e proposte per lavoro futuro.

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Wang, Tianheng Ph D. Massachusetts Institute of Technology. "Network navigation with scheduling." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115653.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 155-164).
Network navigation is a promising paradigm for enabling location-awareness in dynamic wireless networks. A wireless navigation network consists of agents (mobile with unknown locations) and anchors (possibly mobile with known locations). An agent can estimate its locations based on inter- and intra-node measurements, as well as prior knowledge. In the presence of limited wireless resources, only a subset rather than all of the node pairs can perform inter-node measurements at a time. The procedure of selecting node pairs at different time instants for inter-node measurements, referred to as network scheduling, affects the time evolution of agents' localization errors. The key to achieve high navigation accuracy and efficient channel usage is to maximize the benefit from agents' inter-node measurements. Therefore, it is critical to design scheduling algorithms that decide for each agent with whom and when to perform inter-node measurements. This thesis introduces situation-aware scheduling that exploits network states to adaptively schedule agents' inter-node measurements. In particular, an analytical framework is developed to determine the effects of scheduling strategies and network settings on the localization error evolution. Furthermore, efficient and distributed situation-aware scheduling algorithms tailored for wireless navigation networks are designed, leading to high navigation accuracy and efficient channel usage. The first part of the thesis develops an analytical framework to determine the localization error evolution as a function of scheduling algorithms and network settings. In particular, both sufficient and necessary conditions for the boundedness of the error evolution are provided. Furthermore, opportunistic and random situation-aware scheduling strategies are proposed, and bounds on the corresponding time-averaged network localization errors are derived. These strategies are proved to be optimal in terms of the error scaling with the number of agents. Finally, the navigation accuracy is shown to be improved by sharing the wireless resources among multiple measurement pairs instead of allocating all the resources to a single pair at a time. The second part of the thesis designs efficient slotted and unslotted situation-aware scheduling algorithms tailored for wireless navigation networks based on the analytical results from the first part. The algorithm parameters, such as access probabilities and access rates, are optimized based on bounds for the time-averaged network localization error (NLE). The proposed algorithms lead to significant performance improvement compared with scheduling algorithms from wireless communication networks. The third part of the thesis develops a framework for the design of random-access-based distributed and asynchronous scheduling algorithms for wireless navigation networks, in which the channel access probabilities are optimized based on the evolution of agents' localization errors. The proposed algorithm achieves higher navigation accuracy and more efficient channel usage than the commonly used carrier sensing multiple access (CSMA) algorithm from wireless communication networks, at the cost of minimal communication overhead and computational complexity. The performance improvement is shown via numerical and experimental results. The contributions of this thesis provide a framework for the analysis and design of scheduling algorithms for wireless navigation networks, leading to high-accuracy, efficient, and flexible network navigation.
by Tianheng Wang.
Ph. D.

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Kotowick, Kyle (Kyle Jordan). "Adaptive modality selection for navigation systems." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120379.

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Thesis: Ph. D. in Human Systems Integration, Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2018.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 203-221).
People working in extreme environments, where their mental and physical capabilities are taxed to the limit, need every possible advantage in order to safely and effectively perform their tasks. When these people -- such as soldiers in combat or first responders in disaster areas -- need to navigate through various areas in addition to performing other concurrent tasks, the combination can easily result in sensory or attentional overload and lead to major reductions in performance. Since the tasks that these people must perform often require intense visual attention, such as scanning an area for threats or targets, conventional visual navigation systems (map-based GPS displays) add to that visual workload and put users in danger of divided attention and failure to perform critical functions. This has lead to substantial research in the field of tactile navigation systems, which allow the user to navigate without needing to look at any display or use his or her hands to operate the system. While they have been shown to be extremely beneficial in many applications, tactile navigation systems are incapable of providing the detailed information that visual systems can and they make it more difficult to use the tactile sensory modality for other notifications or alerts due to tactile interference. This dissertation proposes a novel navigation system technology: one that adaptively and dynamically selects a navigation system's modality based on a variety of factors. Each modality has varying levels of compatibility with the different types of concurrent tasks, which forms the basis for the adaptive modality selection (AMS) algorithm. Additionally, there are time-varying factors called switching cost, sensory adaptation, and habituation that negatively affect navigation performance over long-duration navigation tasks; by switching between navigation system modalities when these effects have reached a point of notable performance loss, their effects can be mitigated. By considering both the task-specific benefits of each modality as well as the time-varying effects, an AMS navigation system can dynamically react to changes in the user's mission or environmental parameters to provide consistent, reliable navigation support. The research presented in this dissertation is divided into three phases, each involving a distinct human-participants experiment. The first phase investigated methods for selecting which modality to use for providing information to users when they are already completing other high-workload tasks. Results from the 45-participant experiment indicated that the primary consideration should be to avoid presenting multiple sources of information through the tactile modality simultaneously, suggesting that an AMS navigation system should ensure that the tactile modality is never used for navigation while it is also necessary for concurrent tasks. The second phase investigated the effects of sensory adaptation and habituation on navigation tasks, and evaluated whether it was possible to alleviate those effects by regularly changing between navigation system modalities. Results from the 32-participant experiment indicated that periodically changing between navigation system modalities induces a transient switching cost after each change, but that it also prevents long-term adaptation/habituation. The analysis indicated that the optimal time to change modalities was approximately once every five minutes. The third and final phase investigated the efficacy of an AMS navigation system algorithm, the design of which was informed by the results from the first two phases of research in combination with results from prior work. Participants were required to navigate while also performing various concurrent tasks while using a conventional single-modality navigation system, a multimodal system, or the novel adaptive system. Results from the 32-participant experiment indicated that when a user must both navigate and perform a concurrent non-navigation task simultaneously, use of an AMS navigation system can result in improved performance on both the navigation and the concurrent task.
by Kyle Kotowick.
Ph. D. in Human Systems Integration

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Alvarsson, Karl Sigurður Alvar. "Perspectives of joint financing of air navigation services." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33353.

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According to Chapter XV of the Chicago Convention, the Joint Financing Aid has been successfully applied in the North Atlantic Region since 1948. The Agreement on the Joint Financing of Certain Air Navigation Services in Iceland, the main topic of this thesis, has ensured the availability of the service and facilities in the Reykjavik Flight Information Region, in accordance with the Standards and recommended practices of the Annexes to the Chicago Convention. The services were at first financed by the participating States, but later on user charges were gradually introduced and, since 1981, they became the principal means of services financing.
During the last thirty years, a series of significant social, economic and technical developments has changed the aviation and the air navigation services environment. This thesis examines the evolution of the Agreement and the general technical and economic tendencies that are likely to affect its future.
This thesis critically examines the Agreement in light of ICAO policy on the joint support aid and the general economic situation surrounding the Agreement. (Abstract shortened by UMI.)

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Andrade, Alessandra Arrojado Lisbôa de. "Navigating into the new millennium : the global navigation satellite system regulatory framework." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ64258.pdf.

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Chari, Raja Jon Vurputoor 1977. "Autonomous orbital rendezvous using angles-only navigation." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8716.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2001.
Includes bibliographical references (p. 193-195).
This study assesses navigation performance for rendezvous and close approach applications where on-board navigation must be accomplished through the use of angles-only measurements by developing various relative motion orbital trajectories. Chaser vehicle maneuvers designed to enhance the estimator's observability of the downrange distance to the target are considered. The target vehicle is assumed to be non-maneuvering and in a near-circular orbit. The modeled system includes representative scenarios from the Orbital Express mission. Although a wide array of angle measurement sensors are available, their use in orbital rendezvous is generally limited by the fact that they are unable to provide direct target ranging information which leads to significant downrange error accumulation in the navigation filter. These navigation problems inherent to angles-only measurements in a natural motion environment are first qualitatively studied both analytically and through linear covariance modeling. It is shown that different target-chaser geometries lead to different navigation uncertainties in target downrange distance. The conclusions drawn from considering natural motion geometries are used to study candidate maneuver-assisted trajectories. The results from this study are used to select and combine the most promising maneuver-assisted trajectories for more in-depth consideration as potential scenarios for the Orbital Express mission. These selected trajectories are then analyzed in depth to determine the interdependency of range observability using angles-only navigation with angular sensor quality, inertial measurement accuracy, attitude determination accuracy, and trajectory design. Using the Orbital Express mission as a baseline, maneuver-assisted trajectories for angles-only navigation are tested with realistic error models to validate the rules of thumb created for improved angles-only navigation even in the presence of biases, misalignments, and degraded sensors. The results show that using well-chosen trajectories leads to navigation error uncertainties acceptable for rendezvous applications when only angular measurements are available.
by Raja Jon Vurputoor Chari.
S.M.

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Mitchell, Megan Leigh 1978. "CDGPS-based relative navigation for multiple spacecraft." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/17782.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.
Includes bibliographical references (p. 129-134).
This thesis investigates the use of Carrier-phase Differential GPS (CDGPS) in relative navigation filters for formation flying spacecraft. This work analyzes the relationship between the Extended Kalman Filter (EKF) design parameters and the resulting estimation accuracies, and in particular, the effect of the process and measurement noises on the semimajor axis error. This analysis clearly demonstrates that CDGPS-based relative navigation Kalman filters yield good estimation performance without satisfying the strong correlation property that previous work had associated with "good" navigation filters. Several examples are presented to show that the Kalman filter can be forced to create solutions with stronger correlations, but these always result in larger semimajor axis errors. These linear and nonlinear simulations also demonstrated the crucial role of the process noise in determining the semimajor axis knowledge. More sophisticated nonlinear models were included to reduce the propagation error in the estimator, but for long time steps and large separations, the EKF, which only uses a linearized covariance propagation, yielded very poor performance. In contrast, the CDGPS-based Unscented Kalman relative navigation Filter (UKF) handled the dynamic and measurement nonlinearities much better and yielded far superior performance than the EKF. The UKF produced good estimates for scenarios with long baselines and time steps for which the EKF would diverge rapidly. A hardware-in-the-loop testbed that is compatible with the Spirent Simulator at NASA GSFC was developed to provide a very flexible and robust capability for demonstrating CDGPS technologies in closed-loop.
(cont.) This extended previous work to implement the decentralized relative navigation algorithms in real time.
by Megan Leigh Mitchell.
S.M.

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Boehmer, Rudy Avi 1974. "Navigation analysis and design for Mars entry." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/46645.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1998.
Includes bibliographical references (p. 127-128).
This thesis presents a navigation system design for a lander module during entry at Mars. The system estimates the state vector with an extended Kalman filter, which utilizes update information provided by the following measurement types: two-way range with orbiting satellites, two-way Doppler with orbiting satellites, two-way range with surface beacons, two-way Doppler with surface beacons, altitude, and relative surface velocity. Filter performance of the navigation design is analyzed using a computer simulation of such a spacecraft during Mars entry. Simulation results are presented to evaluate the effectiveness of the filter using each of the individual measurement types. In addition, the sequence in which the measurements are filtered that yields the most favourable results is determined. Using this optimal sequence, the simulation produces a final standard deviation of 105.25 m for the lander position and 0.168 m/s for the lander velocity, compared to final standard deviations of 1218.85 m and 3.700 m/s for a case where no measurements are processed.
by Rudy Avi Boehmer.
S.M.

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Nuzzo, Nicholas C. (Nicholas Christopher) 1974. "Effects of propagation techniques on relative GPS navigation." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/8965.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1999.
Includes bibliographical references (p. 173-176).
Various service vehicles are being developed to resupply the International Space Station (ISS). These service vehicles and the ISS will perform automated space rendezvous. The performance of a relative GPS navigation filter for this application is presented. Specifically, the effects of four different techniques for propagating the filter state are demonstrated and evaluated. These techniques include, (1) integration of the equations of motion accounting for J2, J3, J4 and aerodynamic drag, (2) first-order equations of relative motion that account for the effects of J2 and include a second-order conic approximation, (3) the Universal Keplerian state transition matrix, and (4) the use of the Clohessy-Wiltshire equations of relative motion. GPS measurements were simulated and included errors due to Selective Availability, clock bias, clock drift, and receiver noise. The relative navigation filter used pseudorange and delta-range measurements to estimate the filter state which included the relative position and relative velocity between the vehicles conducting the space rendezvous. The results demonstrated that all four techniques surpassed the performance requirements on relative position and velocity errors. However, integrating the equations of motion, technique (1), resulted in the best performance. The filter state errors for this technique were the smallest and remained within the 3 [sigma] covariance bounds for all the cases studied. Effects due to eccentricity were observed in the remaining propagation techniques with the worst noted in technique (4). The most significant perturbation was shown to be J2, producing significant propagation and filter errors when the state was being propagated by methods (3) and (4), which did not account for it.
by Nicholas C. Nuzzo.
S.M.

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Gingiss, Anthony John. "Navigation analysis of Earth-Moon libration point missions." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/42542.

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Richter, Charles Andrew. "Autonomous navigation in unknown environments using machine learning." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112457.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 165-175).
In this thesis, we explore the problem of high-speed autonomous navigation for a dynamic mobile robot in unknown environments. Our objective is to navigate from start to goal in minimum time, given no prior knowledge of the map, nor any explicit knowledge of the environment distribution. Faced with this challenge, most practical receding-horizon navigation methods simply restrict their action choices to the known portions of the map, and ignore the effects that future observations will have on their map knowledge, sacrificing performance as a result. In this thesis, we overcome these limitations by efficiently extending the robot's reasoning into unknown parts of the environment through supervised learning. We predict key contributors to the navigation cost before the relevant portions of the environment have been observed, using training examples from similar planning scenarios of interest. Our first contribution is to develop a model of collision probability to predict the outcomes of actions that extend beyond the perceptual horizon. We use this collision probability model as a data-driven replacement for conventional safety constraints in a receding-horizon planner, resulting in collision-free navigation at speeds up to twice as fast as conventional planners. We make these predictions using a Bayesian approach, leveraging training data for performance in familiar situations, and automatically reverting to safe prior behavior in novel situations for which our model is untrained. Our second contribution is to develop a model of future measurement utility, efficiently enabling information-gathering behaviors that can extend the robot's visibility far into unknown regions of the environment, thereby lengthening the perceptual horizon, resulting in faster navigation even under conventional safety constraints. Our third contribution is to adapt our collision prediction methods to operate on raw camera images, using deep neural networks. By making predictions directly from images, we take advantage of rich appearance-based information well beyond the range to which dense, accurate environment geometry can be reliably estimated. Pairing this neural network with novelty detection and a self-supervised labeling technique, we show that we can deploy our system initially with no training, and it will continually improve with experience and expand the set of environment types with which it is familiar.
by Charles Andrew Richter.
Ph. D.

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Tweddle, Brent Edward. "Computer vision based navigation for spacecraft proximity operations." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/57545.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2010.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 219-226).
The use of computer vision for spacecraft relative navigation and proximity operations within an unknown environment is an enabling technology for a number of future commercial and scientific space missions. This thesis presents three first steps towards a larger research initiative to develop and mature these technologies. The first step that is presented is the design and development of a " flight-traceable" upgrade to the Synchronize Position Hold Engage Reorient Experimental Satellites, known as the SPHERES Goggles. This upgrade enables experimental research and maturation of computer vision based navigation technologies on the SPHERES satellites. The second step that is presented is the development of an algorithm for vision based relative spacecraft navigation that uses a fiducial marker with the minimum number of known point correspondences. An experimental evaluation of this algorithm is presented that determines an upper bound on the accuracy and precision of this system. The third step towards vision based relative navigation in an unknown environment is a preliminary investigation into the computational issues associated with high performance embedded computing. The computational characteristics of vision based relative navigation algorithms are discussed along with the requirements that they impose on computational hardware. A trade study is performed which compares a number of dierent commercially available hardware architectures to determine which would provide the best computational performance per unit of electrical power.
by Brent Edward Tweddle.
S.M.

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Mu, Beipeng. "Task-driven navigation and mapping with resource constraints." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107046.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 129-139).
Breakthroughs in sensing technology in the past decade have greatly improved the capability of robots to sense complicated, partially-known environments. For example, RGB-D cameras and Velodyne scanners allow for the collection of massive amounts of sensor data in real time. These new technologies enable many new possibilities for mobile robots, such as driverless cars, drones, delivery robots, and autonomous marines vehicles. While advances in sensing technology have enabled robots to obtain data quickly and cheaply, robots are typically resource-constrained in storing and processing all the of the data. New algorithmic challenges arise that how to process data selectively to be directly useful for the robot tasks, and use sparse models to meet resource constraints. In many of the applications, a fundamental problem for autonomous systems is the ability to simultaneously map the environment and localize within, especially when there is no global reference. This problem is often referred to as Simultaneous Localization and Mapping (SLAM). This thesis particularly studies three related key technologies in SLAM, sparse mapping, autonomous path planning and interacting with natural objects, but in the content of being task-driven and resource-constrained. In part one, given a pre-collected dataset, only a subset of landmarks and measurements of landmarks are carefully selected to build a sparse map, such that the robot still achieves good navigation performance (minimal collision) with this sparse map. Part two extends the robot's capability to plan its own trajectories while autonomously exploring an unknown environment to build maps. A Topological Feature Graph is developed to maintain sparsity of the map but still enable collision check for path planning. The new approach uses a .unified information metric to explicitly balance exploration of new environment and exploitation of mapped environments. Part three uses deep neural networks to detect real-world objects as landmarks for map building. The new algorithm explicitly takes into account false positives in object detection, and performs object data association and SLAM simultaneously. The proposed approaches are compared with existing methods using both detailed simulations as well as real-world experiments. The results show that the new approaches have good navigation and mapping performance with significantly less memory and computation resources.
by Beipeng Mu.
Ph. D.

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Chaudhari, Pratik (Pratik Anil). "Algorithms for autonomous urban navigation with formal specifications." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90726.

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Thesis: E.A.A., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 58-62).
This thesis addresses problems in planning and control of autonomous agents. The central theme of this work is that integration of "low-level control synthesis" and "high-level decision making" is essential to devise robust algorithms with provable guarantees on performance. We pursue two main directions here. The first part considers planning and control algorithms that satisfy temporal specifications expressed using formal languages. We focus on task specifications that become feasible only if some of the specifications are violated and compute a control law that minimizes the level of unsafety of the system while guaranteeing that it still satisfies the task specification. Examples in this domain are motivated from an autonomous car navigating an urban landscape while following road safety rules such as "always travel in the left lane" and "do not change lanes frequently" or an electric vehicle in a mobility-on-demand scenario. The second part of the thesis focuses on multi-agent control synthesis, where agents are modeled as dynamical systems and they interact with each other while sharing the same road infrastructure - all the while respecting the same road driving rules expressed as LTL specifications. We discuss algorithms that identify well-defined notions in the game theory literature such as Stackelberg equilibria and non-cooperative Nash equilibria under various information structures. This work builds upon ideas from three different fields, viz., sampling-based motion-planning algorithms to construct efficient concretizations of general, continuous time dynamical systems, model checking for formal specifications that helps guarantee the safety of a system under all scenarios, and game theory to model the interaction between different agents trying to perform possibly conflicting tasks.
by Pratik Chaudhari.
E.A.A.

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15

Carter, Scott Shannon. "Precision orbit determination from GPS receiver navigation solutions." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/17418.

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Bradley, Christopher Powell. "Navigation of unknown environments using high-level actions." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/124173.

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This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 91-96).
Goal-oriented, autonomous navigation through previously unexplored environments presents challenges to a robot on a number of different fronts. First, the robot must construct a representation of its environment that enables it to reason about entering and exploring unknown regions, while still allowing it to backtrack through previously explored space. Additionally, the robot must be able evaluate the expected cost of plans through unobserved space to reach its objective efficiently. This thesis presents work that addresses each of these challenges with respect to a mobile robot. The Learned Subgoal Planner provides an abstraction for planning using high-level actions to reduce the complexity of the planning problem. Using learning to estimate the cost of different actions, a 21% improvement in terms of distance traveled versus a baseline was shown in a simulated environment replicating real-world floor plans. A second contribution is a novel mapping paradigm which represents the world with a graph of actions build from monocular visual input. To construct this map, a convolutional network is used to detect high-level actions from vision. The map is shown to be robust to noise, with particular attention paid to the problem of associating detected actions from frame to frame using a learned association metric. Preliminary results show this metric is an improvement compared to a baseline.
by Christopher Powell Bradley.
S.M.
S.M. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics

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Campbell, Jacob L. "Application of Airborne Laser Scanner - aerial navigation." Ohio University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1147294952.

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Leber, Douglas Eric. "A systems analysis of the impact of navigation instrumentation on-board a Mars rover, based on a covariance analysis of navigation performance." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/42544.

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Chabot, Thomas. "Integrated navigation architecture analysis for Moon and Mars exploration." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32440.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2005.
Includes bibliographical references (p. 127-131).
The new solar system exploration objectives announced in January 2004 have the goal of sending humans back to the Moon by the year 2020 in preparation for human exploration of Mars. Advanced, but cost effective, surface navigation and communication capabilities are required to support these new exploration objectives. In response to this need, a set of three Navigation/Communication architectures have been designed: Minimalist, Simple, and Performance, as well as several augmentation options. The design and refinement of these architectures was performed using numerous models and tools developed for this work. A unique feature of the analysis in this thesis was that the architectures considered combine different navigation assets (onboard, on-surface and on-orbit). The three main Navigation/Communication architectures were then evaluated and compared using several metrics, such as navigation coverage, accuracy and operability, communication metrics, and mass. Based on this analysis we recommend the initial deployment of the Simple architecture for surface exploration of the Moon and Mars with a gradual accretion of assets and possibly transition to the Performance architecture. A specific combination of onboard and vision-based sensors is recommended as the fundamental navigation equipment. In addition to this navigation study, a control-based analysis of formation flying dynamic models around the libration point L₂ of the Sun-Earth system is also presented. The objective of this research was to assess the quality of different dynamical models of the relative motion of two spacecraft in orbit around Sun-Earth L₂.
(cont.) This was done using open-loop simulations to investigate the intrinsic fidelity of each model and closed-loop simulations to evaluate the impact of modeling errors on fuel costs. The conclusion from this analysis is that the more sophisticated models give appreciable better closed-loop performance, and that the difference appears to be sufficient to justify the additional effort required to implement them on-line.
by Thomas Chabot.
S.M.

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Lefebvre, de Plinval-Salgues Henry Jacques. "Analysis of relative navigation architectures for formation flying spacecrafts." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35575.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2006.
Includes bibliographical references (p. 191-194).
Many future space missions will involve fleets with a large number of satellites flying in formation. Indeed, such fleets provably offer more reliability, redundancy, scalability and repeatability. However, large fleets also represent a challenge, especially for the navigation algorithms, which must provide an accurate estimate of the state of the fleet, with minimum requirements. Furthermore, as the number of satellites in the fleet increases, the computations to be performed increase dramatically, as well as the synchronization and communication requirements, making the design of efficient algorithms a difficult challenge. Based on previous studies, Decentralized Algorithms were designed to spread the computational task. Hierarchic Algorithms were also studied in order to reduce the synchronization requirements. This thesis presents both analytical and numerical comparisons of these algorithms in terms of accuracy, computational complexity, synchronization, and communication. The Decentralized and Hierarchic Algorithms were shown to have good performance in terms of accuracy, while involving far fewer computations than the Centralized Algorithm. As a result, they can be used as scalable algorithms for large formation flying fleets.
(cont.) The thesis investigated two additional problems often associated with navigation filters. The first study considers the problem of processing delayed measurements. Three strategies are analyzed, and compared in terms of the accuracy of the estimate they perform, and the memory and computations they require. One of these approach is shown to be efficient, being accurate without requiring heavy computations nor memory. The second study analyzes a particular instability of the Extended Kalman Filter, encountered when two sensors have very different accuracies. The instability is explained and a method to fix it is proposed. In the example analyzed the method proves to be efficient in addressing the instability.
by Henry Jacques Lefebvre de Plinval-Salgues.
S.M.

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Paschall, Stephen C. (Stephen Charles) 1978. "Mars entry navigation performance analysis using Monte Carlo techniques." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/16661.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.
Includes bibliographical references (p. 169-170).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
An atmospheric entry and descent full-state navigation filter is developed and presented. Using this filter a navigation performance analysis is performed to examine the effects of various instrument packages and differing sensor scenarios for the entry and descent phase of the Mars Aerial Regional-scale Environmental Survey (ARES) mission. Deterministic simulation in conjunction with Monte Carlo techniques is used to verify navigation performance of an extended Kalman filter. This analysis specifically compares the performance of four feasible instrument packages. examines navigation performance as it varies with changes to initial sensor activation altitude, and examines error sources and covariance trends for this entry and descent scenario. The results from the analysis show that large attitude uncertainty resulting from the LN200 IMU bias causes a breakdown of the filter algorithm dlue to nonlinearities. The addition of a surface relative velocity measurement, to the altimeter measurement provides only marginal position uncertainty improvement and significant velocity and attitude uncertainty improvement. Increasing the initial altitude for sensor activation provides slight improvements in position uncertainty. but large velocity and attitude uncertainty improvements. Finally, it is shown that initial state uncertainty dominates over all other error sources in this navigation analysis. Error growth within the principal states (position, velocity, and attitude) is predominantly a product of the near-constant attitude uncertainty as it transfers from the innocuous roll attitude channel into the more consequential pitch and yaw attitude channels.
by Stephen C. Paschall, II.
S.M.

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Woffinden, David C. 1976. "On-orbit satellite inspection : navigation and [Delta]v analysis." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28862.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.
In title on t.p., "[Delta]" appears as the upper-case Greek letter.
Includes bibliographical references (p. 213-215).
Since the late 1950's when the first man-made satellite was launched into space, there has been a keen interest to inspect these orbiting spacecraft. In the past, there have been employed a variety of inspection methods which primarily consisted of different ground observation facilities. Unfortunately, ground-based sensors are often limited to the weather conditions and the particular flight path of the satellite. To overcome these and other obstacles, the inspection sensors can be moved from the ground and placed on spacecraft in orbit dedicated for satellite inspections. Is it possible for a miniaturized satellite to perform these inspections while on orbit? In this thesis, a small inspection satellite concept is developed and then verified using a high-fidelity 6 degree-of-freedom simulation. A detailed angles-only navigation analysis and [delta]v performance analysis of three different inspection trajectories are performed. The results of this analysis show the feasibility of angles-only rendezvous navigation and the over-all inspection satellite concept while validating the implemented flight algorithms.
by David C. Woffinden.
S.M.

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Axelrad, Penina. "Near Earth orbit determination and rendezvous navigation using GPS." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/15034.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1986.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND AERO.
Bibliography: leaves 144-148.
by Penina Axelrad.
M.S.

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Dave, Pratik K. (Pratik Kamlesh). "Autonomous navigation of distributed spacecraft using intersatellite laser communications." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/128308.

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This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Thesis: Ph. D. in Space Systems, Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2020
Cataloged from the PDF of thesis.
Includes bibliographical references (pages 149-157).
Autonomous navigation refers to satellites performing on-board, real-time navigation without external input. As satellite systems evolve into more distributed architectures, autonomous navigation can help mitigate challenges in ground operations, such as determining and disseminating orbit solutions. Several autonomous navigation methods have been previously studied, using some combination of on-board sensors that can measure relative range or bearing to known bodies, such as horizon and star sensors (Hicks and Wiesel, 1992) or magnetometers and sun sensors (Psiaki, 1999), however these methods are typically limited to low Earth orbit (LEO) altitudes or other specific orbit cases. Another autonomous navigation method uses intersatellite data, or direct observations of the relative position vector from one satellite to another, to estimate the orbital positions of both spacecraft simultaneously.
The seminal study of the intersatellite method assumes the use of radio time-of-flight measurements of intersatellite range, and a visual tracking camera system for measuring the inertial bearing from one satellite to another (Markley, 1984). Due to the limited range constraints of passively illuminated visual tracking systems, many of the previous studies restrict the separation between satellites to less than 1,000 kilometers (e.g., Psiaki, 2011), or simply drop the use of measuring intersatellite bearing and rely solely on obtaining a large distribution of intersatellite range measurements for state estimation (e.g., Xu et al., 2014). These assumptions have limited the assessment of the performance capability of autonomous navigation using intersatellite measurements for more general mission applications.
In this thesis, we investigate the performance of using laser communication (lasercom) crosslinks in order to achieve all necessary intersatellite measurements for autonomous navigation. Lasercom systems are capable of measuring both range and bearing to a receiving terminal with greater precision than traditional methods, and can do so over larger separations between satellites. We develop a simulation framework to model the measurements of intersatellite range and bearing using lasercom crosslinks in distributed satellite systems, with consideration of varying orbital operating environments, constellation size and distribution, and network topologies. We implement two estimation algorithms: an extended Kalman filter (EKF) used with Monte Carlo sampling for performance analyses, and a Cram~r-Rao lower-bound (CRLB) computation for uncertainty analyses.
We evaluate several case studies modeled off of existing and planned constellation missions in order to demonstrate the new capabilities of performing intersatellite navigation with lasercom links in both near-Earth and deep-space orbital applications. Performance targets are generated from the current state-of-the-art navigation capabilities demonstrated by Global Navigation Satellite Systems (GNSS) in Earth-orbit, and by radiometric tracking and orbit estimation using the Deep Space Network (DSN) in deep-space orbits. For Earth-orbiting applications, we simulate a relay satellite system in geosynchronous orbit (GEO) inspired by current optical communications missions in development by both ESA and NASA, and Walker constellations in LEO inspired by the upcoming mega-constellations for global broadband internet service, such as those proposed by SpaceX and Telesat.
In both case studies, we demonstrate improved navigation performance over the current state-of-the-art in GNSS receiver technologies by using intersatellite measurements from lasercom crosslinks. Monte Carlo simulations show median total position errors better than 3 meters in LEO, 12 meters in GEO, and 45 meters in high-altitude or highly-eccentric orbits (HEO), showing promise as an alternative navigation method to GNSS in Earth-orbiting environments. We also simulate current and future Mars-orbiting missions as examples of deep-space applications. In one case study, we create an ad-hoc constellation comprised of low-altitude Mars exploration orbiters modeled off of current Mars-orbiting missions. In a second case study, we focus on a high-altitude constellation proposed for dedicated Earth-to-Mars networked communications.
Again, in both case studies, we demonstrate improved navigation performance over the current state-of-the-art in DSN radiometric orbit solutions by using intersatellite measurements from lasercom crosslinks. Monte Carlo simulations show stable median total position errors better than 25 meters for Mars-orbit, which demonstrates a notable improvement both spatially and temporally versus DSN orbit estimation, mitigating the large cost and time constraints associated with DSN tracking. These results demonstrate the promise of using lasercom intersatellite links for autonomous navigation, offering enhanced performance over current state-of-the-art capabilities, and a greater applicability to missions both near Earth and beyond.
by Pratik K. Dave.
Ph. D. in Space Systems
Ph.D.inSpaceSystems Massachusetts Institute of Technology, Department of Aeronautics and Astronautics

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Grenfell, Peter W. (Peter William). "GNSS-based relative navigation for LEO nanosatellite laser communications." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/128311.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2020
Cataloged from PDF of thesis.
Includes bibliographical references (pages 153-162).
The Size, Weight, and Power (SWaP) efficiency of laser communications make it a good fit for development in concert with rising interest in small satellite mission concepts. The CubeSat Laser Infrared CrossinK (CLICK) mission has the objective of demonstrating the first Low-Earth orbit (LEO) nanosatellite crosslink. The need for precise and accurate pointing with laser instruments motivates a formalized, systematic approach to fulfilling this need called Pointing, Acquisition, and Tracking (PAT). The focus of this work is the initial Global Navigation Satellite System (GNSS) based relative navigation pointing process for LEO crosslinks and downlinks. In Chapter 2, the baseline CLICK pointing budgets are given for crosslink and downlink relative navigation based body pointing. For crosslink, the 9 9 th percentile angular relative navigation errors are 1367 [mu]rad & 76.58 [mu]rad for the minimum 25 km range and maximum 580 km range cases, respectively.
The corresponding 99.7% pointing losses are -0.278 dB & -0.182 dB, with margins of 1.222 dB & 1.318 dB relative to the -1.5 dB requirement. For downlink, the 9 9 th percentile angular relative navigation error is 17.29 [mu]rad, with a corresponding 99.7% pointing loss of -0.189 dB and margin of 1.311 dB. The crosslink and downlink access durations are also determined by simulation. In Chapter 3, using Cowell's method with only an appropriate central body gravity model, model-induced propagation error is maintained to less than 50 m for intervals up to 90 minutes and less than 25 m for intervals up to 30 minutes. This corresponds to crosslink 9 9 th percentile angular errors of less than 600 [mu]rad at 25 km and less then 40 [mu]rad at 580 km. Earth-Centered-Inertial (ECI) to Earth-Centered-Earth-Fixed (ECEF) transformations are discussed for ground station position prediction, and even with the simplest transformation formulation, position error remained less than 16 m.
Model-induced error for all downlink cases had a 9 9 th percentile error of less than 32 [mu]rad. The relative navigation error for crosslinks is analyzed for the baseline CLICK configuration of directly propagating GPS fixes. For crosslinks across all configurations, the 9 9 th percentile angular errors are less than ~2000 [mu]rad at 25 km and less then ~200 [mu]rad at 580 km, corresponding to 99.7% pointing losses less than -1.235 dB at 25 km and -0.427 dB at 580 km and corresponding margins greater than 0.265 dB and 1.073 dB, respectively. For downlinks, the 9 9 th percentile error across all cases is less than ~45 [mu]rad, which corresponds to 99.7% pointing losses of less than -0.434 dB with margins greater than 1.066 dB across all cases, including simplified Earth rotation models. In Chapter 4, Kalman filtering algorithms are explored to improve GNSS-based orbit determination for relative navigation in LEO.
Three different formulations of the Extended Kalman Filter (EKF) correction and prediction subroutines are explored in depth: 1) the Conventional EKF (CEKF); 2) the Joseph Sequential EKF (JSEKF); 3) the UD Sequential EKF (UDSEKF). Implementation and time complexity differences are discussed for Runge-Kutta methods used to solve state prediction problem and for matrix exponential methods used to approximate continuous-time covariance prediction. The EKF for orbit determination using GNSS measurements is formulated using the ECI position and velocity, a central body gravity model, and nondimensionalization. The CEKF, JSEKF, and UDSEKF filter formulations are evaluated on three metrics: efficiency as per analytical time complexity results, consistency, and orbit determination accuracy. The overall ranking is 1) UDSEKF, 2) CEKF, 3) JSEKF.
With the addition of Kalman filtering, across all crosslink configurations, the 9 9 th percentile angular errors are less than -1000 [mu]rad at 25 km and less then ~100 [mu]rad at 580 km, and the 99.7% pointing losses are less than -0.623 dB at 25 km and -0.421 dB at 580 km with corresponding margins greater than 0.877 dB and 1.079 dB, respectively. This corresponds to improvements of at least 50% for the angular error across all cases. For the CLICK hardware configuration, filtering has a significantly greater effect on pointing loss at shorter ranges. Applying filtering for downlinks yields an improvement in the overall 9 9 th percentile error across all cases by at least 22.2% to less than ~35 [mu]rad. As anticipated from previous analysis, filtering has a negligible impact on pointing loss for downlink due to the dominance of mechanical and spacecraft errors in the CLICK downlink pointing budget. Filtering had the greatest impact for short range crosslinks.
Nevertheless, for future missions with more stringent requirements, narrower beams, improved mechanical errors, and/or significantly worse GPS measurement errors, filtering may also have significant benefit for long range crosslinks and for downlinks.
by Peter W. Grenfell.
S.M.
S.M. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics

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O'Shea, Patrick Joseph S. M. Massachusetts Institute of Technology. "Multiple hypothesis positioning algorithm for robust GPS-denied navigation." Thesis, Massachusetts Institute of Technology, 2018. https://hdl.handle.net/1721.1/122396.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2018
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 113-117).
In the past few decades, GPS has become the dominant source of precision navigation and is often required for many modern systems to operate. However, recent exposure of GPS vulnerabilities have called into question its overall resiliency and shown necessity for robust alternatives. Precision celestial navigation using Draper's Skymark technique can be used to replace GPS. However, these systems rely on prior position knowledge for system initialization. In GPS-denied scenarios, prior position knowledge may not be available or trustworthy. Similarly, other GPS-denied navigation techniques such as landmark navigation or vision-aided navigation can be difficult when there is limited prior position information. Therefore, the Multiple Hypothesis Positioning algorithm is developed in this thesis to provide robust positioning in GPS-denied navigation scenarios where little or no prior position knowledge is available.
The proposed robust positioning algorithm makes use of Multiple Hypothesis Tracking techniques to develop an object identification and observer positioning framework. The Multiple Hypothesis Positioning framework is developed broadly in this thesis to encompass multiple applications of the proposed algorithm. The Multiple Hypothesis Positioning framework is applied to two separate applications including a Lost-at-Sea positioning algorithm and a Lost-in-a-Forest positioning algorithm. The Lost-at-Sea application serves as an initialization process for Draper's Skymark technique in situations where no prior position knowledge is available. The Lost-in-a-Forest positioning algorithm uses pattern matching techniques to identify trees near an observer and compare these locally observed trees to a global map of all tree locations. The pattern matching techniques are combined with the Multiple Hypothesis Positioning framework to determine the observer's global position.
Both applications were tested in robust Monte Carlo simulations with positive results. Overall, the proposed Multiple Hypothesis Positioning algorithm and framework prove effective tools for robust positioning in GPS-denied navigation applications where prior position information is unavailable.
"The material included in this thesis was funded through internal research and development funds from the Charles Stark Draper Laboratories. This research is this thesis was supported by the Draper Education Office and the Draper Fellowship Program"--Page 5.
by Patrick Joseph O'Shea.
S.M.
S.M. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics

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27

Yates, Max William Major. "Angles-only navigation technique for maneuver-free spacecraft proximity operations." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113719.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis. Vita.
Includes bibliographical references (pages 242-256).
The technique of angles-only navigation consists of a single surveyor making line-of-sight observations of a target to deduce a relative navigation state from a sequence of angle measurements. Historically, angles-only navigation has been impeded by a range ambiguity problem in its many applications, especially those involving linear dynamical models. A classical solution to the problem is for the surveyor to perform precise maneuvers to change the nominal angle profile between the surveyor and the target. In the space environment, the orbital dynamics are inherently nonlinear and natural orbit perturbations have the effect of continuous micro-maneuvers. These advantageous conditions present an opportunity to overcome the ambiguity problem and enable spacecraft to navigate passively with a lightweight, low-power camera without the associated fuel cost of maneuver-assisted angles-only navigation. This technology has military and civilian utility for a wide range of missions involving rendezvous and proximity operations, most notably with non-cooperative resident space objects (RSOs). A novel procedure is developed that constrains the admissible region of the target's natural motion to a set of unit-less parameters. These parameters and an arbitrary scale factor combine to describe a single orbit hypothesis that translates into a set of classical orbital elements (COEs). A cluster of uniformly sampled hypotheses are propagated and rendered into angle vs. angle-rate curves. Although these curves exhibit very similar trends for all admissible hypotheses, the angles are slightly different at common angle-rate waypoints during certain parts of the orbit. The set of angle and range hypotheses at these waypoints form a linear map to transform the observed angle to a range approximation. Photometry can complement this procedure with a secondary mapping from the timing of virtual eclipse events if a sufficient time differential is manifested across the admissible hypotheses. A nonlinear least squares (NLS) filter is designed to refine the accuracy of the initial orbit solution using a novel application of Kolmogorov-Arnold-Moser (KAM) theorem to model the Earth's geopotential to any degree and order in the filter dynamics. The KAM torus conveniently captures the full nonlinear effects that make angles-only navigation possible in space and is computationally superior to numerically integrated reference trajectories for exact temporal synchronization with angle observations. Numerical results are presented that demonstrate the first angles-only navigation technique for natural motion circumnavigation trajectories without prior knowledge of the Target's state. An analytical proof is developed to compliment and verify the results.
by Max William Yates.
Ph. D.

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Steiner, Theodore J. III (Theodore Joseph). "A unified vision and inertial navigation system for planetary hoppers." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/85812.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 139-146).
In recent years, considerable attention has been paid to hopping as a novel mode of planetary exploration. Hopping vehicles provide advantages over traditional surface exploration vehicles, such as wheeled rovers, by enabling in-situ measurements in otherwise inaccessible terrain. However, significant development over previously demonstrated vehicle navigation technologies is required to overcome the inherent challenges involved in navigating a hopping vehicle, especially in adverse terrain. While hoppers are in many ways similar to traditional landers and surface explorers, they incorporate additional, unique motions that must be accounted for beyond those of conventional planetary landing and surface navigation systems. This thesis describes a unified vision and inertial navigation system for propulsive planetary hoppers and provides demonstration of this technology. An architecture for a navigation system specific to the motions and mission profiles of hoppers is presented, incorporating unified inertial and terrain-relative navigation solutions. A modular sensor testbed, including a stereo vision package and inertial measurement unit, was developed to act as a proof-of-concept for this navigation system architecture. The system is shown to be capable of real-time output of an accurate navigation state estimate for motions and trajectories similar to those of planetary hoppers.
by Theodore J. Steiner, III.
S.M.

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Steiner, Theodore J. III (Theodore Joseph). "Utility-based map reduction for ground and flight vehicle navigation." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98802.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 167-182).
Maps used for navigation often include a database of location descriptions for place-recognition (to enable localization or loop-closing), which permits bounded-error navigation performance. A standard localization system must describe the entire operational environment in its place-recognition database. A standard pose-graph-based simultaneous localization and mapping (SLAM) system adds a new place-recognition database entry for every new vehicle pose, which grows linearly and unbounded in time and thus becomes unsustainable. To address these issues, this thesis proposes a new map-reduction approach that pre-constructs a fixed-size place-recognition database amenable to the limited storage and processing resources of the vehicle by exploiting the high-level structure of the environment and vehicle motion. In particular, the thesis introduces the concept of location utility - which encapsulates the visitation probability of a location and its spatial distribution relative to nearby locations in the database - as a measure of the value of potential localization or loop-closure events to occur at that location. While finding the optimal reduced location database is NP-hard, an efficient greedy algorithm is developed to sort all the locations in a map based on their relative utility without access to sensor measurements or the vehicle trajectory. This enables predetermination of a generic, limited-size place-recognition database containing the N best locations in the environment. A street-map simulator using city-map data and a terrain relative navigation simulator using terrestrial rocket flight data are used to validate the approach and show that an accurate map and trajectory reconstruction (pose-graph) can be attained even when using a place-recognition database with only 1% of the entries of the corresponding full database.
by Theodore J. Steiner III.
Ph. D.

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Forbes, Nicholas Lloyd. "Behavioural adaptation to in-vehicle navigation systems." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/10798/.

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This PhD investigates driver behavioural adaptation to in-vehicle navigation systems (IVNS). Behavioural adaptation is receiving an increasing amount of research attention in traffic psychology, but few studies have directly considered the concept in relation to IVNS. The thesis aims were addressed using a range of quantitative and qualitative methodologies. Using two online surveys, over 1300 drivers (including over 1000 IVNS users) were sampled, to identify a range of positive, neutral and negative aspects of end-user behavioural adaptation to IVNS in terms of both safety and navigational efficiency. The first survey (N=450) aimed at drivers in general, showed that IVNS users believe they commit some common driving errors (e.g. misreading signs when leaving a roundabout) significantly less frequently than ordinary drivers who do not use these systems, but that they also feel they drive without fully attending to the road ahead significantly more frequently. The second survey (N=872) was aimed at IVNS users only, and further explored distracted driving. This survey found that the majority of IVNS users have interacted with their system while driving (e.g. to enter a destination), and that some do so frequently. It also showed that system reliability is a key issue affecting most current IVNS users, revealing that some drivers have followed inaccurate as well as illegal and potentially dangerous, system-generated route guidance information in a range of different contexts. A longitudinal diary study (N=20) then collected rich qualitative data from a sample of worker drivers who regularly used their IVNS in unfamiliar areas. The data collected illustrated the diverse contexts in which drivers experience aspects of behavioural adaptation to IVNS identified in the surveys. Both the IVNS user-survey and diary study also identified key demographic individual difference variables (most notably age and computing skill) that were associated with the extent to which driver’s experienced different manifestations of behavioural adaptation to IVNS. Moreover, other individual difference variables (e.g. complacency potential, system-trust, confidence) were found to be associated with more specific behavioural adaptations. Two simulator studies investigated system interaction while driving. The first (N=24) demonstrated the poor degree of correspondence between drivers’ perceptions of driving performance when entering destinations while driving (relative to normal driving) and objective performance differences between these conditions. The second simulator study (N=24) showed that safety and training based interventions designed to reduce the extent to which drivers use IVNS while driving or to improve their performance if they do had only a modest effect on dependent measures. This thesis represents the first attempt in the literature to bring together research from diverse areas of human factors and traffic psychology to consider behavioural adaptation to in-vehicle navigation systems. By associating a range of these issues with behavioural adaptation to IVNS, it has indirectly increased the scope of several salient, previous research findings. Moreover, by investigating many of these issues in depth, using both quantitative and qualitative methodological approaches, it has set the foundation for future work. Such work should aim to explore many of the issues raised, and develop effective remediating or mitigating intervention strategies for negative behavioural adaptations that could adversely affect driving safety, as well as to encourage and support those which may be considered more positive.

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Rochlis, Jennifer Lisa. "A vibrotactile display for aiding extravehicular activity (EVA) navigation in space." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/49981.

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Butts, David LaGrange. "Light pulse atom interferometry at short interrogation times for inertial navigation." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/71453.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, February 2012.
"February 2012." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 141-150).
Light pulse atom interferometry with cold atoms is a promising inertial sensing technology for high accuracy navigation. At present, laboratory atom interferometers match or surpass state of the art mechanical and optical inertial sensors in terms of sensitivity and long term stability. Conventional laboratory systems, however, do not achieve sufficient bandwidth or dynamic range to operate in a dynamic environment; furthermore, the size, weight and power of laboratory sensors are unsuitable for many applications. In this thesis, atom interferometry is realized at shorter interrogation times (<15 ms as opposed to >100 ms), in which the required sensitivity, bandwidth and dynamic range of navigation systems becomes feasible. A cold atom gravimeter testbed using atom interferometry with stimulated Raman transitions was developed, which executed the entire measurement cycle in a compact vacuum cell (~ ~ 80 cc). The system demonstrated an inferred sensitivity of 2 [mu]g[square root] Hz for an interrogation time of 2T = 10 ms (based on measured phase SNR, scale factor, and repetition rate). With realistic improvements to the apparatus, it could achieve a sensitivity of <1 [mu]g[square root]Hz, advancing toward the realization of a compact, atom-based inertial measurement unit with unprecedented performance. In addition, a method for increasing the momentum splitting of Raman pulse interferometers with sequential Raman pulses was demonstrated, and interferometer area was increased by up to a factor of nine without altering the interrogation time (corresponding to a momentum splitting of 18hk, the largest reported for Raman pulse interferometry). Composite Raman pulses were implemented to improve population transfer efficiency, which limits the achievable increase in precision. Finally, the effect of coherent population trapping (CPT) induced by Raman pulse atom optics was identified as a source of systematic phase shifts in the [pi]/2 - [pi] - [pi]/2 interferometer used for sensing acceleration and rotation. CPT effects were modeled in a three-level (A) atom, and were experimentally characterized using atom interferometry. Based on the magnitude of measured coherences induced by Raman pulse atom optics, phase shifts of several milliradians should occur for a typical GHz-scale laser detuning. A method for suppressing this bias in realistic operation by Raman beam propagation direction reversal is proposed.
by David L. Butts.
Ph.D.

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Aoudé, Georges Salim. "Threat assessment for safe navigation in environments with uncertainty in predictability." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68401.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 213-224).
This thesis develops threat assessment algorithms to improve the safety of the decision making of autonomous and human-operated vehicles navigating in dynamic and uncertain environments, where the source of uncertainty is in the predictability of the nearby vehicles' future trajectories. The first part of the thesis introduces two classes of algorithms to classify drivers behaviors at roads intersections based on Support Vector Machines (SVM) and Hidden Markov Models (HMM). These algorithms are successfully validated using a large real-world intersection dataset, and can be used as part of future driver assistance systems. They are also compared to three popular traditional methods, and the results show significant and consistent improvements with the developed algorithms. The second part of the thesis presents an efficient trajectory prediction algorithm that has been developed to improve the performance of future collision avoidance and detection systems. The proposed approach, RR-GP, combines the Rapidly-exploring Random Trees (RRT) based algorithm, RRT-Reach, with mixtures of Gaussian Processes (GP) to compute dynamically feasible paths, in real-time, while embedding the flexibility of GP's nonparametric Bayesian model. RR-GP efficiently approximates the reachability sets of surrounding vehicles, and is shown in simulation and on naturalistic data to improve the performance over two standard GP-based algorithms. The third part introduces new path planning algorithms that build upon the tools that have been previously introduced in this thesis. The focus is on safe autonomous navigation in the presence of other vehicles with uncertain motion patterns. First, it presents a new threat assessment module (TAM) that combines the RRT-Reach algorithm with an SVM-based intention predictor, to develop a threat-aware path planner. The strengths of this approach are demonstrated through simulation and experiments performed in the MIT RAVEN testbed. Second, another novel path planning technique is developed by integrating the RR-GP trajectory prediction algorithm with a state-of-the-art chance-constrained RRT planner. This framework provides several theoretical guarantees on the probabilistic satisfaction of collision avoidance constraints. Extensive simulation results show that the resulting approach can be used in real-time to efficiently and accurately execute safe paths. The last part of the thesis considers the decision-making problem for a human-driven vehicle crossing a road intersection in the presence of other, potentially errant, drivers. The proposed approach uses the TAM framework to compute the threat level in real-time, and provides the driver with a warning signal and the best escape maneuver through the intersection. Experimental results with small autonomous and human-driven vehicles in the RAVEN testbed demonstrate that this approach can be successfully used in real-time to minimize the risk of collision in urban-like environments.
by Georges Salim Aoudé.
Ph.D.

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Broll, Anthony W. "Trust in adaptive automation in a tactical search and navigation task." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105090.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 271-275).
Handheld smart phone devices incorporate communication and mapping tools into small military squads to increase their effectiveness. These devices link a squad with headquarters, satellites and unmanned aerial vehicles to provide them with up to date intelligence. This information is filtered by adaptive technology which prioritizes the most vital pieces. An indoor search and navigation experiment was conducted to determine the appropriate type of automation (adaptive or adaptable) to prioritize this intelligence for decision makers in an uncertain, time-critical scenario. An experiment was conducted with eight males in their early 20's actively serving the US military or part of a training program. Subjects utilized an app on an HTC Desire designed to navigate the user indoors from a start QR code to a goal QR code while collecting additional QR codes to maximize their point totals within three minutes. Subjects utilized the app in one of two modes: computer-select (adaptive automation) and user-choice (adaptable automation). In addition, updates in the form of floor closures would occur in half of the 24 trials. Results of the study showed a preference for computer-select with better performance on the primary task. Users ended up using both systems as a type of user-choice by disregarding the app's path planning beyond the initial route. The user preference for computer-select was tied to the ability of the system to adjust to the human instead of the user having to tell the system what it was doing. Subjects wanted the flexibility of adaptable and user-choice before the trial to plan and define their own route, but once the trial began, the subject's temporal demand was too high to want to maintain that level of control beyond the subject's actions in the real world.
by Anthony W. Broll.
S.M.

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Lopez, Brett Thomas. "Low-latency trajectory planning for high-speed navigation in unknown environments." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107052.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 105-109).
The ability for quadrotors to navigate autonomously through unknown, cluttered environments at high-speeds is still an open problem in the robotics community. Advancements in light-weight, small form factor computing has allowed the application of state-of-the-art perception and planning algorithms to the high-speed navigation problem. However, many of the existing algorithms are computationally intensive and rely on building a dense map of the environment. Computational complexity and map building are the main sources of latency in autonomous systems and ultimately limit the top speed of the vehicle. This thesis presents an integrated perception, planning, and control system that addresses the aforementioned limitations by using instantaneous perception data instead of building a map. From the instantaneous data, a clustering algorithm identifies and ranks regions of space the vehicle can potentially traverse. A minimum-time, state and input constrained trajectory is generated for each cluster until a collision-free trajectory is found (if one exists). Relaxing position constraints reduces the planning problem to finding the switching times for the minimum-time optimal solution, something that can be done in microseconds. Our approach generates collision-free trajectories within a millisecond of receiving perception data. This is two orders of magnitude faster than current state-of-the art systems. We demonstrate our approach in environments with varying degrees of clutter and at different speeds.
by Brett Thomas Lopez.
S.M.

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36

Weigl, Harald Jürgen. "Vision based navigation and control for unmanned free-flying remote vehicles." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/43263.

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Vydhyanathan, Arun. "Effect of atmospheric paticulates on airborne laser scanning for terrain-referenced navigation." Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1163793662.

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Van, Graas Frank. "Hybrid GPS/LORAN-C a next-generation of sole means air navigation." Ohio : Ohio University, 1988. http://www.ohiolink.edu/etd/view.cgi?ohiou1171674578.

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39

Kahraman, Eren. "Navigation Algorithms And Autopilot Application For An Unmanned Air Vehicle." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612797/index.pdf.

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This study describes the design and implementation of the altitude and heading autopilot algorithms for a fixed wing unmanned air vehicle and navigation algorithm for attitude and heading reference outputs. Algorithm development is based on the nonlinear mathematical model of Middle East Technical University Tactical Unmanned Air Vehicle (METU TUAV), which is linearized at a selected trim condition. A comparison of nonlinear and linear mathematical models is also done. Based on the linear mathematical model of the METU TUAV, the classical control methods are applied during the design process of autopilot algorithms. For the confirmation purposes of the autopilot and navigation algorithms, a nonlinear simulation environment is developed in Matlab/Simulink including nonlinear model of the METU TUAV, altitude and heading autopilot loops, nonlinear actuator models, sensor models and navigation model. In the first part of the thesis, feedback signals for the controller are provided by IMU free measurements. In the second part, the feedback signals are provided by an attitude and heading reference mode, which incorporates the gyroscope solutions with the magnetic sensor and accelerometer sensor measurements by using a Kalman filter algorithm. The performance comparison of the controller is done for both cases where the effects of having different modes of the measurement sources are investigated.

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40

Griffiths, Stephen Richard. "Remote terrain navigation for unmanned air vehicles /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1167.pdf.

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41

Poutrel, Richard 1977. "Global Positioning System navigation and digital communications for cooperating Unmanned Air Vehicles." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/82243.

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42

Kremer, Alison Sara. "Linear covariance analysis trade study of autonomous navigation schemes for cislunar missions." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/47795.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2007.
Includes bibliographical references (p. 175-177).
Deep space missions to the Moon and Mars under NASA's Constellation Program are a tangible goal. However, the Deep Space Network (DSN) antennas which provided ground based navigation state updates to spacecraft of the Apollo era are aging and overtaxed. The over-reliance on this ground based system for high accuracy navigation of deep space vehicles presents a distinct challenge. One viable solution to this dilemma is the application of autonomous navigation for deep space vehicles. This thesis investigates the problem of autonomous navigation by conducting a linear covariance analysis trade study on various configurations of autonomous sensors for a representative cislunar mission. The sensor suite is comprised of twelve sensors of varying measurement types and levels of flight readiness: MIMU IMU, LN200 IMU, star tracker, Inertial Stellar Compass (ISC), lunar orbiting beacon (Navsat), lunar ground beacons (Navsites), LIDAR, known lunar landmarks, SkyMark, TDRS, and GPS. A complete formulation of the linear covariance tool (LINCOV) dynamics and mathematical models of the sensors are presented. The primary focus of the study is a scenario based analysis of the navigation position, velocity, and attitude error covariances along the Moon to Earth trajectory for a specified set of sensor configurations. Major trends and observations from the lunar and Earth region navigation error covariances are discussed. Additionally, a short series of sensitivity tests on the sensor error model parameters, measurement geometry, and system process noise were conducted, providing notable insight and incentive for further studies. The conclusions of this trade study point to a promising future for autonomous space navigation.
by Alison Sara Kremer.
S.M.

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43

Fuhry, Douglas Paul. "A design study of onboard navigation and guidance during aerocapture at Mars." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/34037.

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Neirinckx, Peter J. (Peter Joseph). "Autonomous onboard guidance and navigation performance for Earth to Mars transfer missions." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/42522.

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Kaliardos, William N. "Sensors for autonomous navigation and hazard avoidance on a planetary micro-rover." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/49903.

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Willhite, Weldon Barry. "An analysis of ICBM navigation using optical observations of existing space objects." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/57986.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 123).
This thesis investigates the potential of a space-based navigation concept known as Skymark to improve upon the accuracy of inertially-guided intercontinental ballistic missiles (ICBMs). The concept is to use an optical tracker to take line-of-sight measurements to nearby space objects with known ephemerides to update the state knowledge of the onboard inertial navigation system. The set of existing space objects that would be potentially useful for this application are tabulated, and a simulation determines their availability from realistic trajectories. A follow-on navigation simulation investigates the accuracy improvement potential in terms of Circular Error Probable at impact. Two scenarios are investigated, one in which the Skymark system is an add-on aid-to-inertial-navigation for an existing missile system, and one in which the Skymark system is completely integrated with a new inertial navigation unit. A sensitivity analysis is performed to determine how several performance factors affect Skymark accuracy. Finally, a brief discussion of some operational implementation issues is included.
by Weldon Barry Willhite.
S.M.

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47

Goulart, Paul James 1976. "A dynamics based method for accelerometer-only navigation of a spinning projectile." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8094.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2001.
Includes bibliographical references (p. 83).
A method of navigating a gun-launched, spinning projectile using only accelerometers is presented. A linear combination of the outputs of a general configuration of at least 12 accelerometers is shown to provide measurements of angular acceleration and angular rate products of the form w2/i and wiwj. These measurements are used in the development of a 12 state, extended Kalman filter to estimate position, velocity, attitude, and angular rate, with twelve additional states included to estimate accelerometer biases. Assumptions about the dynamic behavior of the vehicle are used to assist in attitude estimation. These assumptions come in two parts. First, that the nose of the vehicle remains pointed along the air-relative velocity vector during flight. Second, that the vehicle lateral angular rates have a secular component due to the vehicle pitching over during flight to maintain this alignment. A digital filter is used to isolate the secular pitch-over component of the estimated rate in an intermediate, non-rolling frame. These dynamics-based estimates are then incorporated as measurements in the navigation filter. A configuration of 12 accelerometers arranged on the faces of a 10 cm cube is used in a six degree of freedom simulation to navigate a projectile spinning at 2 Hz. The navigation filter is shown to reliably estimate angular rates with biases as large as 1 g. Bias state estimation is also shown to compensate for instrument misalignments up to 1 degree. Using the dynamics-based measurements, the navigation filter successfully estimates projectile roll attitude to within 20 degrees for instrument random walk errors up to 2.5 milli-g/[square root] Hz.
by Paul James Goulart.
S.M.

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48

Wetherbee, Lisa D. (Lisa Dawn). "Optimal estimation of the vehicle state in an embedded dopploer/GPS navigation system." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/47361.

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Hassannia, Jeff Hossein. "Navigation performance and integrity monitoring for ballistic missiles using all-in-view GPS." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/47380.

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50

Chaudhry, Atif Iqbal 1973. "Navigation of a high velocity tele-operated ground vehicle through an obstacle rich environment." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/50549.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1999.
Includes bibliographical references (leaf 41).
An experiment was designed and conducted to investigate the use of a priori overhead images in navigating an unmanned tele-operated ground vehicle through an obstacle rich environment. The obstacle courses contained many of the same types of elements that would exist in an urban setting. The corresponding a priori images depicted these obstacle courses but included some drawbacks that could be expected in an overhead image of an urban environment. For instance there were objects on the course that were not depicted on the overhead image and vice versa. The overhead images were prepared in low, medium, and high resolutions. These resolutions, one meter, half meter, and centimeter scale, were selected to be representative of what might be available in real situations. Subjects controlled the vehicle using a joystick, with reference to the a priori image and a real-time video image from the vehicle. The subjects' times to navigate the courses and their paths were recorded during the experiment. From this information, post analysis showed what types of decision errors they made on each course. Statistical analysis showed that there was no significant performance difference between the three different obstacle courses. Subjects took the longest time to navigate the courses using the low resolution overhead images, and took the shortest time with the high resolution images. There was a statistically significant difference between the average course completion time with the medium resolution map and the high resolution map. Medium and high resolution lead subjects to rely less on the video image from the vehicle. This caused them to occasionally make incorrect navigation choices. With low resolution subjects tended to use clearly discernible paths and avoid shortcuts which could have saved time. This nuance in the behavior with different resolutions underscores the importance of experimentation and suggests that further study is necessary.
by Atif Iqbal Chaudhry.
S.M.

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Dissertations / Theses on the topic 'Navigation (Aeronautics)'

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