Graduate Exam Abstract

Brian Breitsch

M.S. Final
June 21, 2017, 10:00 am - 12:00 pm
Engineering Conference Room
Optimal Linear Combinations of GNSS Phase Observables to Improve and Assess TEC Estimation Precision

Abstract: One of the principal observations derived from GNSS (Global Navigation Satellite Systems) signals is ionospheric total electron content (TEC), which is a measure of the density of free electrons (i.e.\ ionosphere plasma density) integrated along the signal path. TEC is typically computed using the difference of dual- frequency signals from a GNSS satellite, thereby taking advantage of the frequency dispersive effects of ionosphere plasma on microwave- band propagation. However, it is difficult to distinguish between the ionosphere and other frequency- dependent effects, such as multipath and satellite antenna phase effects. Newly available triple-frequency GNSS signals allow computation of geometry- ionosphere-free combinations (GIFC) that specifically highlight the impact of residual errors from these effects. This work aims to: 1) introduce a framework for choosing linear estimator coefficients for GNSS parameters, 2) use this system to derive triple- frequency TEC estimator and GIFC coefficients, 3) introduce and summarize typical GIFC signals from real triple-frequency GPS data, 4) highlight the various frequency- dispersive effects that pervade these signals, and 5) use statistics from GIFC signals to assess the impact of error residuals on TEC estimates made using GPS signals.

Adviser: Jade Morton
Co-Adviser: N / A
Non-ECE Member: Anton Betten
Member 3: Charles Rino
Addional Members: N / A

N / A

Program of Study: