Nicolls, M. J., Rodrigues, F. S., Bust, G. S., & Chau, J. L. (2009). Estimating E region density profiles from radio occultation measurements assisted by IDA4D. Journal of Geophysical Research: Space Physics, 114(A10).
An alternative approach for estimating E region density profiles using radio occultation total electron content (ROTEC) measurements is presented. In this approach, the F region contribution to the measured ROTEC is removed using the estimated F region from an assimilative model of ionospheric density. E region density profiles are then obtained from a numerical inversion of the residual ROTEC, which is assumed to be the E region contribution to the ROTEC. The proposed technique has been applied to radio occultation measurements made by the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC), while the F region specification is obtained from the Ionospheric Data Assimilation Four-Dimensional (IDA4D) algorithm. Examples of E region profiles obtained with this approach are presented and compared with nearby radar measurements at the magnetic equator. The results indicate that accurate estimates of the E region peak height and density can be obtained with this approach. This technique may be applicable to the estimation of E region conductivities with the global coverage provided by the radio occultation measurements.