An indirect assessment of the precision of the NmF2 maps computed from the ITU-R database and from FORMOSAT-3/ COSMIC ionospheric radio-occultations

BRUNINI CLAUDIO; AZPILICUETA FRANCISCO; LIMBERGER M.; SCHMIDT M.; DETTMERING D.; LIANG W.

Viena

Conferencia; EGU General Assembly 2014; 2014

The electron density, NmF2, and the height, hmF2, of the ionosphere?s F2 peak are key parameters for modeling the electron density distribution (e.g.: the International Reference Ionosphere (IRI) model [1]), for radio-communication forecast (e.g.: Radio-communication sector of the International Telecommunication Union (ITU-R) recommendations [2]), and other space weather specifications. A commonly used procedure to compute the values of these parameters (when direct measurements are not available) is the use of the ITU-R global maps [3,4], which were established in the early 60s but are still the ITU-R standards. ITU-R maps provide monthly median values of the critical frequency, f0F2, and the propagation factor, M3000F2, for any given Universal Time, latitude, longitude and solar activity level; these parameters are later converted into NmF2 and hmF2 using empirical approximations [5].  We have recently presented a technique aimed at routinely updating the ITU-R maps based on the assimilation of FORMOSAT-3/COSMIC (F-3/C) Ionospheric Radio Occultations (IRO) in the La Plata Ionospheric Model (LPIM) [6]. In this contribution we indirectly assess the precision of the NmF2 maps provide by the ITU-R and by our technique; the assessment is based on the differences between the vertical Total Electron Content (vTEC) provided by the Jason-1 mission, and the corresponding values derived from the LPIM in connection to the ITU-R and to our NmF2 maps