An attempt to establish an empirical error model for the NmF2 and hmF2 parameters computed from IRI

BRUNINI CLAUDIO; AZPILICUETA FRANCISCO; JANCHES D.

ADVANCES IN SPACE RESEARCH

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2014

0273-1177

In this work we explore the possibility of using COSMIC/FORMOSAT-3 radio occultation profiles (ROP) to establish an empirical model that can be used to estimate the errors of the NmF2 and hmF2 parameters computed from the International Reference Ionosphere (IRI) model. The developed procedure starts by scanning and validating the ROP with a re-weighted Least Square procedure complemented with a statistical test. That technique allows us to retrieve the NmF2 and hmF2 parameters ?along with their error estimates? from the ROP. These values are taken as representative of the instantaneous conditions prevailing in the ionosphere and the basement for estimating the errors of the F2 parameters provided by IRI. Such errors are interpreted as a systematic monthly mean bias plus a day-to-day deviation and these two terms are described as five-dimensional functions that depend on: the month, the solar activity level, the geomagnetic conditions, the modip latitude, and the Local Time. Empirical values for these functions are estimated from the ROP in the form of regular grids. Since this research is restricted to low solar activity and quiet geomagnetic conditions, the grid is reduced from five to three dimensions: month, Local Time, and modip.