5. Efficiency of SPLA: Theoretical validation
Efficiency of SPLA in detecting ionospheric disturbances without amplitude aliasing during a geomagnetic storm was theoretically validated by Shimna and Vijayan (2020). In this study, we first theoretically test the efficiency of SPLA in detecting aliasing and artifact free TIPs and CIPs over the conventional methods under two simulated scenarios and then using observational data sets. In the first scenario, the ability to detect sharp static variations was tested on a synthetic TEC time series added with step functions. In the second scenario, power of resolving the sharp static variations from the perturbations of comparable amplitude were tested using a synthetic TEC time series superimposed with both sharp static variations and a simulated perturbation.
The synthetic TEC was obtained by modeling the TEC using International Reference Ionosphere model IRI-2012 (Bilitza et al., 2014) at every IPP (IRI-TEC) along the satellite track traced by GPS satellite PRN04 observed at a uniform interval of 30 seconds from Hyderabad GPS station (HYDE) on 1st December 2004 from 06:52UT to 13:22UT (Fig. 2. Top-left). The satellite track will be represented throughout this paper by PRN (Psuedo Random Noise) number of the GPS satellite prefixed with four letter GPS station code from where the GPS satellite was observed, for example, HYDE04.