A New Mapping Function for Spaceborne TEC Conversion Based on the Plasmaspheric Scale Height

Mengjie Wu,Wei Zhou,Yansong Meng,Peng Guo,Xiaogong Hu,Xingyuan Han,Junchen Xue

doi:10.3390/rs13234758

Abstract

The mapping function is crucial for the conversion of slant total electron content (TEC) to vertical TEC for low Earth orbit (LEO) satellite-based observations. Instead of collapsing the ionosphere into one single shell in commonly used mapping models, we defined a new mapping function assuming the vertical ionospheric distribution as an exponential profiler with one simple parameter: the plasmaspheric scale height in the zenith direction of LEO satellites. The scale height obtained by an empirical model introduces spatial and temporal variances into the mapping function. The performance of the new method is compared with the mapping function F&K by simulating experiments based on the global core plasma model (GCPM), and it is discussed along with the latitude, seasons, local time, as well as solar activity conditions and varying LEO orbit altitudes. The assessment indicates that the new mapping function has a comparable or better performance than the F&K mapping model, especially on the TEC conversion of low elevation angles.

Highlights

This paper proposed a new model of an low Earth orbit (LEO)-based total electron density content (TEC) mapping function based on a prior model of the plasmaspheric scale height
The new mapping model is driven by the only free parameter, height in the plasmasphere (HP), obtained either from realistic observations or the empirical model
The performance of this mapping function is assessed by the simulated TEC conversion experiments based on the global core plasma model (GCPM) electron density field

Summary

Introduction

Many low Earth orbit (LEO) satellite missions, ionospheric exploration is greatly facilitated by various spaceborne measurements. Several successful LEO missions, such as Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), contribute greatly to the ionospheric modeling and data assimilation system [1,2,3,4,5]. One significant product provided by these satellites is the sounding measurements that contain the total electron density content (TEC) along the signal paths. To obtain the absolute TEC from the raw GNSS/LEO observations, data analysis centers and scientific researchers have devoted great efforts into the main procedures, including the cycle slip detection and correction, carrier-phase to pseudorange leveling, multipath effect correction, and the differential code bias (DCB) estimation [6,7,8,9,10].

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