Equatorial Plasma Bubble Irregularity Layer Reconstruction Using L‐Band Intensity Scintillation Data

Dual frequency L‐band radio signals transmitted from satellites are routinely used to estimate the slant total electron content (STEC) along the signal path. Ionospheric irregularities of scale sizes extending from tens of kilometers to a few hundred meters, when present in the path of these signals, cause signal frequency‐dependent scintillations in amplitudes and phases of the signals. These give rise to errors in the estimated STEC. In the past, indices derived from intensity scintillations have been theoretically related to variations in the estimated STEC, using a statistical description of the irregularities. The aim of the present paper is to obtain a deterministic estimate of variations in the true STEC from observed intensity scintillations. The phase‐screen approximation is used to theoretically relate weak L‐band scintillations to variations in the true STEC due to the presence of an irregularity layer. A new technique is developed to reconstruct the irregularity layer using scintillation data on a L1 signal transmitted from a geostationary satellite and recorded at a low latitude station, Gadanki. Evolution of the irregularity layers on three nights of March 2022, are compared with the STEC along the same signal path, estimated from L1 and L5 signals recorded at Gadanki, and also with the signal‐to‐noise ratio (SNR) map available for one of the nights, from an on‐site 30 MHz radar. Role played by ambient ionospheric conditions such as post‐sunset height of the equatorial F layer and F‐layer peak density, in the evolution of the irregularity layers is investigated using ionosonde data.