Comparison between RO and Digisonde ionospheric peak characteristics over low-latitudes

The objective of this study is to perform a comparison between ionospheric characteristics (foF2, hmF2) as measured from the Global Navigation Satellite System (GNSS) radio occultation (RO) FORMOSAT7/COSMIC2 (F7/C2) constellation mission along with collocated (in space and time) manually scaled data from Digisondes at Fortaleza, Cachoeira Paulista and Santa Maria. This preliminary comparison demonstrates that there is no clear systematic latitude dependent discrepancy between the two techniques, as established by past studies based on FORMOSAT3/COSMIC (F3/C) measurements. However there is evidence to suggest that over each station this discrepancy varies in accordance to solar activity in terms of hmF2.