The critical frequency of the F2-layer (foF2) is an important parameter in estimating the total electron content (TEC) of the ionosphere, which is necessary for predicting the ionospheric time delay in GPS applications. The foF2 data from Ahmedabad, which is in the equatorial anomaly region, are modelled using a multilayer neural network trained with back-propagation algorithm. The IRI-2001 mod...

Ionospheric modeling across the Indian low latitudes continues to be a challenging task because of day-to-day variability pertaining underlying complex equatorial and latitude electrodynamics. In this paper, we aimed at developing an ionospheric Total Electron Content (TEC) model based on Singular Spectrum Analysis (SSA) using Global Positioning System (GPS)-TEC observations (from 2009 2019) Be...

This article is a review of Global Navigation Satellite Systems for space scientists who are interested in how GNSS signals and observables can be used to understand ionospheric dynamics and, conversely, how ionospheric dynamics affect the operational capabilities of GPS. The most common form of GNSS is the Global Positioning System (GPS); we will first review its operating principles and then ...

The forecasting of ionospheric electron density has been great interest to the research scientists and engineers’ community as it significantly influences satellite-based navigation, positioning, communication applications under influence space weather. Hence, present paper adopts a long short-term memory (LSTM) deep learning network model forecast total content (TEC) by exploiting global posit...

With the appearance of such satellite systems as GPS, GLONASS, Galileo, and others, the total electron content TEC measured by means of navigational satellites became a key parameter characterizing a state of the ionized space. In turn, functioning of navigational and telecommunication systems needs models of TEC for an estimation of accuracy of positioning, for the short-term and long-term pre...

We analyze retrospectively/prospectively the transient variations of six different physical parameters in atmosphere/ionosphere during M7.8 and M7.3 earthquakes Nepal, namely: 1) outgoing longwave radiation (OLR) at top atmosphere (TOA); 2) GPS/TEC; 3) very-low-frequency (VLF/LF) signals receiving stations Bishkek (Kyrgyzstan) Varanasi (India); 4) Radon observations; 5) Atmospheric chemical pot...