Moving through varied and complex environments every day is something that most people do with ease. However, if the input from the visual system is unavailable (e.g., damage to the optic nerves or smoke in a burning building), navigating and avoiding obstacles becomes much more demanding. It is therefore desirable to develop a navigation aide for use where visual input has become unavailable. There is a small body of research concerning such navigation aides and their efficacy. However, many issues that may have serious human factors repercussions for such a system are unexplored. This study was conducted in order to examine the effect of an attentionally demanding distractor task on wayfinding performance with an audio only navigation aide, in this case the System for Wearable Audio Navigation (SWAN). The distractor task was found to have a significant impact on wayfinding performance, which decreased when both tasks were performed simultaneously. However, performance on the distractor task improved during this time, in some cases reaching performance levels similar to when the distractor task was performed by itself. This result may be due to participants shifting attention to the task they perceive to be more difficult when asked to do both simultaneously, in this case the distractor task.

Personal robotics applications require autonomous mobile robot navigation methods that are safe, robust, and inexpensive. Two requirements for autonomous use of robots for such applications are an automatic motion planner to select paths and a robust way of ensuring that the robot can follow the selected path given the unavoidable odometer and control errors that must be dealt with for any inexpensive robot. Additional difficulties are faced when there is more than one robot involved. In this dissertation, we describe a new roadmapbased method for mobile robot navigation. It is suitable for partially known indoor environments and requires only inexpensive range sensors. The navigator selects paths from the roadmap and designates localization points on those paths. In particular, the navigator selects feasible paths that are sensitive to the needs of the application (e.g., no sharp turns) and of the localization algorithm (e.g., within sensing range of two features). We present a new sectorbased localizer that is robust in the presence of sensor limitations and unknown obstacles while still maintaining computational efficiency. We extend our approach to teams of robots focusing on quickly sensing ranges from all robots while avoiding sensor crosstalk, and reducing the pose uncertainties of all robots while using a minimal number of sensing rounds. We present experimental results for mobile robots and describe a webbased route planner for the Texas A&M campus that utilizes our navigator.

During the Age of Exploration, navigation evolved from a field filled with superstition into a modern science in Portugal, Spain, and England. The most common navigation instruments utilized and their subsequent innovations are discussed. The refinement of these instruments led to increased accuracy in cartography, safer shipping, and increased trade globally in the period. In order to have the most comprehensive collection of navigation instruments, I investigated 165 shipwrecks dated between 1500 and 1700. Each of these vessels have been located, surveyed, and/or excavated in whole or in part. A comprehensive list of these vessels, compiled for the first time, has been included. This thesis analyzes navigation-related artifacts recovered from 27 of these shipwreck sites. These instruments provide the basis to develop a typology for archaeologists to more closely date these finds. The navigation instruments recovered from the wreck of LaBelle (1686) are discussed in detail. These instruments and related historical documents kept by the navigator provide a more comprehensive picture of the instruments’ accuracy and usefulness. This thesis particularly focuses on the nocturnal/planisphere recovered from the site. This unique instrument is one of only four known to exist worldwide and remains accurate enough to be utilized today. Analysis by a modern astronomer has been included, as well as a partial translation of the common names for constellations inscribed on the instrument. These common names provide some important insights into the received knowledge of sailors and non-academic astronomy during this period. It is hoped that this thesis will be of assistance to archaeologists working to identify, study, and appreciate navigational instruments recovered from shipwrecks. With increased documentation and closer dating, these instruments will become a more valuable portion of the archaeological record.

This research analyzes and demonstrates the local position determination problem on Earth using a novel instrument, the Compass Star Tracker. Special focus is given to the theoretical development of the mathematics of local position determination, the design and fabrication of a proof-of-concept instrument, an error source analysis, and the experimental tests used to validate the position determination concepts. Star sensors are typically used as attitude determination instruments on spacecraft orbiting Earth. In this capacity, the star sensor determines the orientation of the spacecraft using digital images of the stars. This research utilizes the basic functionality of the star sensor in a new way; the orientation information from the star image is used to determine a user's latitude and longitude coordinates on Earth. This concept is valuable because it allows users to determine their position autonomously. The fundamental concepts that enable local position determination were originally published in Drs. Samaan, Mortari, and Junkins (AAS 04-007). This research improves upon that work by eliminating the zenith-orientation constraint and providing several crucial theoretical corrections. In addition to the position determination mathematics, this research provides analysis of the theoretical and practical error sources associated with the position determination problem. This research also details the design, fabrication, and experimental test program of a proof-of-concept Compass Star Tracker. Together, the theoretical development, error analysis, instrument design, and test program serve as validation of the the position determination concept. This work is intended as the first of many steps toward eventual deployment of autonomous position determination sensors on the Moon and Mars.

A self-contained, portable, inertial and positional measurement system was developed and tested for an HGU-55 model fighter pilot helmet. The system, designated the Portable Helmet Instrumentation System (PHIS), demonstrated the recording of accelerations and rotational rates experienced by the human head in a flight environment. A compact, self-contained, “knee-board” sized computer recorded these accelerations and rotational rates during flight. The present research presents the results of a limited evaluation of this helmet-mounted instrumentation system flown in an Extra 300 fully aerobatic aircraft. The accuracy of the helmet-mounted, inertial head tracker system was compared to the aircraft-mounted referenced system. The ability of the Portable Helmet Instrumentation System to record position, orientation and inertial information in ground and flight conditions was evaluated. The capability of the Portable Helmet Instrumentation System to provide position, orientation and inertial information with sufficient fidelity was evaluated. The concepts demonstrated in this system are: 1) calibration of the inertial sensing element without external equipment 2) the use of differential inertial sensing equipment to remove the accelerations and rotational rates of a moving vehicle from the pilot’s head-tracking measurements 3) the determination of three-dimensional position and orientation from three corresponding points using a range sensor. The range sensor did not operate as planned. The helmet only managed to remain within the range sensor’s field of view for 37% of flight time. Vertical accelerations showed the greatest correlation when comparing helmet measurements to aircraft measurements. The PHIS operated well during level flight.

Th. doct.--Universiteit Leiden, 2003.

Marburg, Univ., Diss., 2009

Thesis (M.S. in Hydrographic Science)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Wash, C. H. Second Reader: Schnebele, K. J. "September 1990." Description based on title screen as viewed on December 22, 2009. DTIC Descriptor(s): Radiometers, Navigation Reference, Interactions, Accuracy, Theses, Identification, Navigation, Images, Searching, Navigation Satellites, Artificial Satellites, Windows, Vector Analysis, Operators(Personnel), Earth(Planet), Birds, Matching, Automatic Pilots, Shores, Position(Location), Global. DTIC Identifier(s): Satellite Navigation, Program Listings. Author(s) subject terms: Image navigation, binary correlation, automatic landmarking. Includes bibliographical references (p. 78-81). Also available in print.

Thèse de doctorat : Histoire grecque : Metz : 2006. / Thèse soutenue sur ensemble de travaux. Bibliogr. p. 473-523. tabl. des fig. p. 525. Index p. 529-555.

Thesis (M.S. in Operations Analysis)--Naval Postgraduate School, June 2004. / Thesis advisor(s): Arnold H. Buss. Includes bibliographical references (p. 123-124). Also available online.