Important note: These codes are allowed for academic uses only.

These codes contain the large lookup tables described in (Qin et al., ESS, 2023):

Inferring the ionospheric state with the far ultraviolet imager on the Fengyun-4C geostationary satellite: Retrieval algorithm and verification


1. NmF2.m is a Matlab code that can be used to derive the nighttime nmf2 from disk 
   observations of the 135.6 nm emission from a geostationary orbit.

2. TEC.m is a Matlab code that can be used to derive the nighttime TEC from disk 
   observations of the 135.6 nm emission from a geostationary orbit.

3. The input parameters are:

1) f107d - daily F10.7 index, between 50 sfu and 400 sfu

2) lat - latitude, between 45S - 45N

3) sza - solar zenith angle, input is allowed for 95 - 180 degree, 
         but better used only for 110 - 180 degree to avoid contamination
         from photoelectron impact excitation

4) znth - emission angle, between 0 - 75 degree. The definition of emission angle
          can be found in the attached figure, which is taken from the GOLD’s Public 
          Science Data Products Guide revision 5.0

5) radi - the 135.6-nm intensity in Rayleigh, observed from a geostationary orbit, 
          must be positive


Please direct any questions to Jianqi Qin, Peking University through email:

jqqin@pku.edu.cn

We welcome academic discussion and collaboration.


