Observations

type    = ob
obstype = synop land
time    = 09:30
range   = 180

Feedback  

type  = fb
obstype = synop land
time    = 11:45
range   = 360

Analysis input  

type    = ai
obstype = ...
time    = 00/06/12/18

Analysis Feedback  

type    = af
obstype = ...
time    = 00/06/12/18