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GTS headers for drifting buoy data start with character string 'IOB'.
Warning to data users: Two timestamps are included in each drifing buoy observation message. Each timestamp is preceded by its related time significance (BUFR element 0 08 021). It must be noted that, in template TM315009, the first timestamp is this of the last known position (value is 26). This of the observation (time significance = 25), also called "nominal reporting time" is in second position. Do not confuse both.
Drifting buoy BUFR data - Survey on October 12th, 2014
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