GNSS radio occultation (RO) measurements have become crucial to provide valuable information on the vertical electron density structure of the Ionosphere. Ionospheric key parameters such as the maximum electron density (NmF2) and the corresponding peak height of the F2 layer (hmF2) can be easily derived. In the current work, in order to assess the accuracy of NmF2 and hmF2 inferred from Formosat-3/COSMIC (F-3/C) RO measurements, an efficient electron density retrieval method, previously developed at the UPC (Barcelona, Spain), has been applied for a period of more than half a solar cycle between 2006 and 2014. Ionosonde measurements from the Space Physics Interactive Data Resource (SPIDR) network have been used as reference. Results show that relative variations of NmF2 differences are in the range of 22%–30% and 10%–15% for hmF2. Equatorial and midlatitude sectors at daytime and dawn present the highest consistency whereas degradations have beendetected in the polar regions during night. Moreover, it has been found that the solar activity can be traced by means of the global averages of NmF2 and hmF2 derived from F-3/C RO, hence becoming alternative indicators of solar activity trends.

Peer Reviewed