Date of Award

3-22-2012

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Electrical and Computer Engineering

First Advisor

Michael J. Stepaniak, PhD.

Abstract

The United States Global Positioning System (GPS), with its great accuracy, receives extensive use by civilians and military organizations throughout the world. However, in areas with limited or partially obstructed views of the sky, such as amongst tall buildings or imposing geographic features, a position solution can be difficult or impossible to obtain as the limited view of the sky decreases the number of visible satellites. Augmenting the GPS constellation by receiving signals from foreign satellite navigation systems as well as using measurements from inertial and barometric sensors can increase the availability of a position solution in a degraded reception environment. This thesis investigates combining the GPS system with foreign navigation systems (i.e., Galileo, GLONASS, and Compass), a barometric altimeter, and inertial sensors. Data for the GPS and GLONASS systems were collected, and the data for the Galileo and Compass systems were simulated. A simulation of downtown Dayton, OH was developed and various combinations of the systems were tested throughout the model to measure the availability of a position solution. A simulation also was developed for an autonomous aerial vehicle flight through the model using a Kalman filter to combine the various sensors with GPS. Augmenting GPS showed great improvements in availability throughout the model of downtown Dayton. Furthermore, augmenting the GPS system with foreign systems allowed the autonomous aerial vehicle to successfully navigate in the simulation, whereas, using only GPS, the vehicle was unable to navigate successfully. This opens up the urban environment to more robust navigation solutions.

AFIT Designator

AFIT-GE-ENG-12-24

DTIC Accession Number

ADA558004

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