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

Publications:
N / A

Program of Study:
ECE-444
ECE-611
ECE-514
MATH-618
MATH-519
MATH-525
ECE-699
MATH-502