Fig. 11
From: Performance assessment of radio occultation data from GeoOptics by comparing with COSMIC data
a Mean, b standard deviation of the fractional refractivity differences \(\left( {\frac{{{\text{N}}_{{{\text{RO}}}} - {\text{N}}_{{{\text{radiosonde}}}} }}{{{\text{N}}_{{{\text{radiosonde}}}} }} \times 100} \right)\) and c counts of observations from COSMIC-1 (red) and GeoOptics (blue) during Period 1. d–f Same information as a–c with the data from COSMIC-2 (green) and GeoOptics (blue) during Period 2