Allan D. Tuma

Date of Award

3-14-2014

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Electrical and Computer Engineering

First Advisor

Meir Pachter, PhD.

Abstract

The motivation of this research is to address the use of bearing-only measurements taken by an optical sensor to aid an Inertial Navigation System (INS) whose accelerometers and gyroscopes are subject to drift and bias errors. The concept of Simultaneous Localization And Mapping (SLAM) is employed in a bootstrapping manner: the bearing measurements are used to geolocate ground features, following which the bearings taken over time of the said ground features are used to improve the navigation state provided by the INS. In this research the INS aiding action of tracking stationary, but unknown, ground features over time is evaluated. It does not, however, address the critical image registration issue associated with image processing. It is assumed that stationary ground features are able to be detected and tracked as pixel representations by a real-time image processing algorithm. Simulations are performed which indicate the potential of this research. It is shown that during wings level flight at constant speed and fixed altitude, an aircraft that geolocates and tracks ground objects can significantly reduce the error in two of its three dimensions of flight, relative to an Earth-fixed navigation frame. The aiding action of geolocating and tracking ground features, in-line with the direction of flight, with a downward facing camera did not provide improvement in the aircraft's x-position estimate. However, the aircraft's y-position estimate, as well as the altitude estimate, were signicantly improved.

AFIT Designator

AFIT-ENG-14-M-79

DTIC Accession Number

ADA611349

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