Abstract
A tomographic method has been developed for reconstructing the topside ionospheric and plasmaspheric electron density distribution using total electron content (TEC) measurements from global positioning system (GPS) receivers aboard the constellation observing system for meteorology, ionosphere, and climate/Formosa Satellite Mission 3 (COSMIC/FORMOSAT-3). Since the COSMIC/FORMOSAT-3 constellation has an orbit altitude of about 800 km, the integral TEC measurements obtained from the topside GPS navigation data are rather small and imposed relevant challenges to obtaining stable electron density reconstructions. However, the developed method can represent the natural variability of the plasma ambient in terms of latitude, altitude, solar activity, season, and local time when analyzing electron density reconstructions during 2008–2013. The method employs independent spatial grids for satellite rising and setting geometries and imposes a set of constraints to stabilize the solution in the presence of noise and ill-conditioned geometry. We further consider background ionosphere and plasmasphere models for electron density initialization and filling data gaps. The quality assessment using TEC and <i>in-situ</i> electron density measurements has shown that the proposed method performs better than the background model, with improvements of about 26% in TEC and 20% in terms of electron density. Our investigation also reveals the necessity of more accurate background electron density representations and precise TEC measurements in order to have better plasmaspheric specifications at high altitudes.
Highlights
Section IV.A shows an internal assessment of the unused COSMIC Total Electron Content (TEC) data and Section IV.B shows an external assessment using Defense Meteorological Satellite Program (DMSP) electron density values as a reference
The developed method can perform reconstructions based on the challenging geometry given by COSMIC TEC measurements, where a statistical analysis was conducted taking 2 years of data from 2008 and 2013
Poor‐quality estimations occurred in nighttime at high-latitude regions due to the ill-conditioned geometry, poor specification of the background, and measurement errors in COSMIC TEC in the order of a few TECU mainly associated with Differential Code Bias (DCB), which are significant when producing reconstruction errors and artifacts while estimating regions with very few electron densities
Summary
THE plasmasphere upper atmosphere is a fully ionized region of the Earth’s dominated by H+ ions and free electrons. Satellite-based TEC data obtained from topside GNSS navigation measurements refer to integrated electron density above LEO satellites and exclude the ionospheric contribution below the LEO orbit height. In this regard, many efforts were conducted to apply satellite-based TEC observations and describe the electron density distribution of the plasmasphere [18], [19], [20]. One of the most prominent methods to estimate the plasmaspheric electron density based on GNSS data is to apply 3D tomographic reconstructions considering the whole constellation of LEO satellites capable of observing TEC measurements [24], [25].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
