Graduate Exam Abstract

Harrison Bourne

M.S. Final
December 2, 2015, 8:00 am - 10:00 am
Mechanical Engineering Conference Room
An Algorithm for Accurate Ionospheric Total Electron Content and Receiver Bias Estimation using GPS Measurements

Abstract: The Ionospheric total electron content (TEC) is the integrated electron density across a unit area. TEC is an important property of the ionosphere. Accurate estimation of TEC and TEC spatial distributions are needed for many space-based applications such as precise positioning, navigation, and timing. The Global Positioning System (GPS) provides one of the most versatile methods for measuring the ionosphere TEC as it has global coverage, high temporal resolution and relatively high spacial resolution. The objective of this thesis is to develop an algorithm for accurate estimation of the TEC using dual-frequency GPS receiver measurements and simultaneously estimates the receiver hardware bias in order to mitigate it’s affect on the TEC. This method assumes the TEC in the portion of sky visible to the receiver can be represented as a two dimensional sheet with an absolute value and spacial gradients with respect to latitude and longitude. A code-phase multipath noise estimation algorithm is integrated with the TEC estimation process to mitigate environmental multipath contamination of the measurements. The integrated algorithm produces an approximate map of local TEC using a single dual-frequency receiver while minimizing both multipath induced errors and the receiver hardware bias. The goal of this method is to provide an accurate map of the ionosphere TEC, in the region local to the receiver, without the need for a network of receivers and in the absence of knowledge of the receiver hardware induced bias. This thesis describes the algorithm and its implementation and attempts to validate the method through comparison with incoherent scatter radar (ISR) data from low, mid, and high latitude locations.

Adviser: Yu (Jade) Morton
Co-Adviser: N/A
Non-ECE Member: Sonia Kreidenweis-Dandy
Member 3: Frank Van Graas
Addional Members: Mazdak Arabi

Bourne, H., and Y. Morton. "GPS receiver ionosphere error correction based on spatial gradients and IGS satellite DCBs." Proceedings of the ION Pacific PNT, Honolulu, HI (2013).

Bourne, Harrison, Morton, Yu, Sulzer, Michael, Milla, Marco, Nguyen, Thao, "GPS Based TEC Estimation Algorithm Evaluation Using Simultaneous Incoherent Scatter Radar Measurements," Proceedings of the ION 2015 Pacific PNT Meeting, Honolulu, Hawaii, April 2015, pp. 78-84.

Program of Study:
ECE 699
ECE 581A6
ECE 581A4
ECE 562
ECE 462
ECE 461
CS 658