Each key can appear several times in a BUFR message. Examples are: 

  1. airTemperature in an upper air report
  2. backscatter in a scatterometer observation

ecCodes provides access by rank of all the keys in the data section of a BUFR message with the following syntax:

 

#to get the third airTemperature in the message
t=codes_get(bufr,'#3#airTemperature') 
#to get the second backscatter in the message
b=codes_get_array(bufr,'#2#backscatter') 

This is a change compared with the key syntax provided before version 0.12.0 where the access by rank was expressed as 'airTemperature#3'