1. Binary Universal Form Representation (BUFR) Paul Hamer November, 2009
Self introduction:
Oliver suggested presentation on BUFR
WMO definition “Binary universal form for the representation of meteorological data“
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 1 1

2. WMO Table Driven Code Forms
Why BUFR is important?
WMO 14th Congress in 2003 supported the adoption of TDCF’s.
TDCF’s include BUFR/CREX and GRIB.
Migration to BUFR to be complete by 2015.
(CREX – Character form for Representation and EXchange.)
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 2 2

3. Global Systems Division (GSD) Earth System Research Laboratory (ESRL)
WMO BUFR
Documentation and standard code tables from WMO (
Edition 4 in use from November 2005 but use of edition 3 use allowed  until 2012.
(Note: A BUFR message shall not mix features of different editions; the content shall be consistent and in accordance with a single edition.)
Version numbers correspond to code table versions.
(Master table version is currently 14).
Master table versions up to and including version 13 are a superset.
A further discussion of tables will be included in metadata.
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 3 3

4. Global Systems Division (GSD) Earth System Research Laboratory (ESRL)
WMO BUFR
BUFR is the name of a binary code for the exchange and storage of data. (Note: Not just meteorological)
The BUFR message consists of a continuous bit-stream made of a sequence of octets (1 octet = 8 bits). 
The terms “BUFR message” and “section” describe logical entities to assist BUFR definition.
A BUFR message consists of one or more subsets of related data defined, described and represented by a single BUFR entity.
The octets of a BUFR message are grouped in sections.
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 4 4

5. Global Systems Division (GSD) Earth System Research Laboratory (ESRL)
WMO BUFR Sections
All WMO TDCF’s break messages into sections. For BUFR these are:
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 5 5

6. Data Description Section
The data description section contains the “descriptors” of data contained in the data section.
Each descriptor shall occupy 2 octets and contain 3 parts: F (2 bits), X (6 bits) and Y (8 bits).
F = 0 is known as the element descriptor that refers to a single element in BUFR Table B.
X denotes the Table B class and Y the entry with that class.
F = 1 refers to replication, F = 2 denotes an operator descriptor and F = 3 denotes a sequence operator.
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 6 6

7. Global Systems Division (GSD) Earth System Research Laboratory (ESRL)
BUFR Table B Example
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 7 7

8. WMO BUFR Issues/Solutions?
Decoding requires access to appropriate tables.
Publish tables in XML
Make all tables available at all National Centers
Format defines no standard way of encoding a given dataset.
Use Templates, i.e. Define the encoding for certain datasets.
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 8 8

9. Global Systems Division (GSD) Earth System Research Laboratory (ESRL)
WMO BUFR
Questions?
Global Systems Division (GSD)
Earth System Research Laboratory (ESRL) 9 9