The primary goal of this work is to summarize spectral meth-
ods to estimate the time delay variations of the detrended Medium
Scale Traveling Ionospheric Disturbances (MSTIDs) signals and pre-
liminarily discuss the potential infuence of the Doppler e fects. The
MSTIDs signals are assumed as the planar waves with the wavelength
between 10-100 kilometers, which are measured from a local high-
dense receivers Global Navigation Satellite System (GNSS) network
for a given satellite. The signals sho...

The primary goal of this work is to summarize spectral meth-
ods to estimate the time delay variations of the detrended Medium
Scale Traveling Ionospheric Disturbances (MSTIDs) signals and pre-
liminarily discuss the potential infuence of the Doppler e fects. The
MSTIDs signals are assumed as the planar waves with the wavelength
between 10-100 kilometers, which are measured from a local high-
dense receivers Global Navigation Satellite System (GNSS) network
for a given satellite. The signals show strong correlation with each
others in the whole observation time series. The time delay of the
detrended MSTIDs signals preprocessed with a speci c overlapped
sliding window can be estimated by several techniques. The data con-
sisted on two detrended MSTIDs signals measured from the GNSS
data on the day 1, 2011 obtained from the small area network in Cal-
ifornia. In this paper we have implemented the following methods
in order to estimate the time delay between signals: (1) Generalized
cross correlation method, which estimates the time delay in time do-
main after the inverse Fourier transform of appropriately weighted
cross power spectrum density, (2) generalized phase spectrum method
directly measured from the appropriately weighted cross power spec-
trum density, (3) phase spectrum di erence method calculated ap-
proximately from the fundamental waves of the signals. The results
with di erent methods show the similar variation of time delay of two
MSTIDs signals. In addition, with the phase spectrum method, the
results can present the clear frequency variation of MSTIDs signals
which may be in
uenced by potential Doppler e ect. Note that the
correct estimate of the delays required of a preprocessing of the data.
The rst di erence of the Vertical Total Electron Contents (dVTEC)
signal was preprocessed by modeling the e ect of the displacement of
the satellite by means of a parabolic component, which is subtracted,
following by detrend of 60-second intervals, decimation and a further
low pass ltering process.
The primary goal of this work is to summarize spectral meth-
ods to estimate the time delay variations of the detrended Medium
Scale Traveling Ionospheric Disturbances (MSTIDs) signals and pre-
liminarily discuss the potential infuence of the Doppler efects. The
MSTIDs signals are assumed as the planar waves with the wavelength
between 10-100 kilometers, which are measured from a local high-
dense receivers Global Navigation Satellite System (GNSS) network
for a given satellite. The signals show strong correlation with each
others in the whole observation time series. The time delay of the
detrended MSTIDs signals preprocessed with a specic overlapped
sliding window can be estimated by several techniques. The data con-
sisted on two detrended MSTIDs signals measured from the GNSS
data on the day 1, 2011 obtained from the small area network in Cal-
ifornia. In this paper we have implemented the following methods
in order to estimate the time delay between signals: (1) Generalized
cross correlation method, which estimates the time delay in time do-
main after the inverse Fourier transform of appropriately weighted
cross power spectrum density, (2) generalized phase spectrum method
directly measured from the appropriately weighted cross power spec-
trum density, (3) phase spectrum dierence method calculated ap-
proximately from the fundamental waves of the signals. The results
with dierent methods show the similar variation of time delay of two
MSTIDs signals. In addition, with the phase spectrum method, the
results can present the clear frequency variation of MSTIDs signals
which may be in
uenced by potential Doppler eect. Note that the
correct estimate of the delays required of a preprocessing of the data.
The rst dierence of the Vertical Total Electron Contents (dVTEC)
signal was preprocessed by modeling the eect of the displacement of
the satellite by means of a parabolic component, which is subtracted,
following by detrend of 60-second intervals, decimation and a further
low pass ltering process.

Citació

Yang, H.; Monte, E.; Hernandez, M. "Internal report. Spectral methods for time delay estimation of MSTIDs signal". 2015.