function qc_flash,f
;
; this code is to quality control the GLM data
; sun glint is indicated by area < 200 km^2 and duration > 0.35 s
;    03/2021     Chuntao Liu
;  
;id=where(f.quality eq 0 and not (f.area le 200 and f.duration ge 0.35),c)
id=where(f.quality eq 0,c)
print,(n_elements(f.lon)-c)*100/n_elements(f.lon),'% GLM flash removed by QC ' 
vars=tag_names(f)
out={}
for k=1,n_elements(vars)-1 do begin 
 out=create_struct(out,vars[k],f.(k)[id])
endfor
return,out
end