5.2 Scenario – 2
In the second scenario, the ionospheric perturbation of the form moving
with an amplitude of 0.6 TECU and velocity of 1 km/s were simulated by
considering a frequency of 3 mHz for a duration of 10 minutes. The
frequency of 3mHz was selected to represent the perturbations common to
both CIPs and TIPs
– (11)
where ΦI and ΛI are
latitude and longitude of IPPs, A is amplitude, , , k is
wave number, ω is angular frequency, t is time andΘ is propagation angle.
The ionospheric perturbations thus simulated was superimposed on the
step function introduced IRI-TEC synthesized in the second scenario to
assess the resolving power of SPLA (Fig. 2, top-right).
Residual method, differential method and SPLA were employed to extract
the simulated perturbation from the newly synthesized IRI-TEC. The
extracted perturbations (rTEC, dTEC and gROT) were analyzed using CWT
(Fig. 2, right).
The results of CWT analysis
manifest that the
SPLA and differential method are better than the residual method in
resolving the signal from sharp static variations (Fig. 2, right). Also,
the residual method fails completely to resolve the sharp static
variations from the simulated signal (Fig. 2, right).
The theoretical efficiency tests carried out considering the two
scenarios clearly establish that the SPLA is superior in (i) detecting
sharp static variations and (ii) distinctly resolving the signal from
sharp static variations which normally occurs due to undetected
cycle-slips or loss of lock in TEC time series.