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.