Global 4D Ionospheric STEC Prediction based on DeepONet for GNSS Rays

TL;DR

This paper introduces DeepONet-STEC, a neural operator model that accurately predicts 4D ionospheric STEC for GNSS applications, demonstrating high accuracy and robustness under various conditions.

Contribution

The paper presents a novel neural operator regression model, DeepONet-STEC, for global 4D ionospheric STEC prediction, outperforming traditional methods especially during storm conditions.

Findings

High-accuracy 3-day 72-hour predictions during quiet periods.

Robust performance during ionospheric storm conditions.

Superiority over traditional deep learning methods.

Abstract

The ionosphere is a vitally dynamic charged particle region in the Earth's upper atmosphere, playing a crucial role in applications such as radio communication and satellite navigation. The Slant Total Electron Contents (STEC) is an important parameter for characterizing wave propagation, representing the integrated electron density along the ray of radio signals passing through the ionosphere. The accurate prediction of STEC is essential for mitigating the ionospheric impact particularly on Global Navigation Satellite Systems (GNSS). In this work, we propose a high-precision STEC prediction model named DeepONet-STEC, which learns nonlinear operators to predict the 4D temporal-spatial integrated parameter for specified ground station - satellite ray path globally. As a demonstration, we validate the performance of the model based on GNSS observation data for global and US-CORS regimes under ionospheric quiet and storm conditions. The DeepONet-STEC model results show that the three-day 72 hour prediction in quiet periods could achieve high accuracy using observation data by the Precise Point Positioning (PPP) with temporal resolution 30s. Under active solar magnetic storm periods, the DeepONet-STEC also demonstrated its robustness and superiority than traditional deep learning methods. This work presents a neural operator regression architecture for predicting the 4D temporal-spatial ionospheric parameter for satellite navigation system performance, which may be further extended for various space applications and beyond.