Slide 1

ecCodes

a new decoder for binary and alphanumeric codes

Enrico Fucile ECMWF

14th MOS Workshop – 20th November 2014 Slide 1

Slide 2

WMO alphanumeric and binary codes

14th MOS Workshop – 20th November 2014 Slide 2

Slide 3

WMO alphanumeric codes: METAR

14th MOS Workshop – 20th November 2014 Slide 3

Slide 4

WMO alphanumeric codes

METAR: Aerodrome observation

METAR EDDF 120550Z 03015KT 1400 R07R/P2000N R07C/P2000N R07L/1900U SN DRSN BR VV/// M04/M04 Q1000 R07L/11//90 R07C/15//90 R07R/15//90 BECMG 4000 NSW=

14th MOS Workshop – 20th November 2014 Slide 4

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WMO alphanumeric codes: SYNOP

14th MOS Workshop – 20th November 2014 Slide 5

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WMO alphanumeric codes: SYNOP

SYNOP: synoptic observation

AAXX 13094 03002 45462 /0514 10097 20073 30238 40256 58011 90850 333 88/11=

14th MOS Workshop – 20th November 2014 Slide 6

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WMO Binary codes

Table Driven Code Forms

BUFR Binary Universal Form for the Representation of meteorological data

GRIB General Regularly-distributed Information in

Binary form

14th MOS Workshop – 20th November 2014 Slide 7

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BUFR elements

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2 bits 6 bits 8 bits

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BUFR operators

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WMO binary codes: BUFR SYNOP

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Delayed replication

Slide 11

BUFR 2 layers model

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Binary

Semantic

Slide 12

airTemperature latitude longitude relativeHumidity day month hour height aircraftFightNumber

channelNumber pressure mixingRatio precipitation Semantic

010010110101010010101010101000010010111110101010101010101010101010100000101000101010010101001010101000101010101010010101010010101000010101110101001010100

BUFR 2 layers model

14th MOS Workshop – 20th November 2014 Slide 12

Binary

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BUFR 2 layers model

14th MOS Workshop – 20th November 2014 Slide 13

010010110101010010101010101000010010111110101010101010101010101010100000101000101010010101001010101000101010101010010101010010101000010101110101001010100 Binary

airTemperature latitude longitude relativeHumidity day month hour height aircraftFightNumber

channelNumber pressure mixingRatio precipitation Semantic 001211 310022 301011 301013 301021 102004 027001 028001 007022 005040 005043 020010 020016 013040 008043 008044 033054 010040

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Semantic

Binary

Slide 15

ecCodes view

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Semantic

Binary

User software

ecCodes

Slide 16

ecCodes semantics approach

dt=codes_get(m,’dewPointTemperature’)

dt9=codes_get(m,’/hour=9/dewPointTemperature’)

backscatter=codes_get(m,’/beamIdentifier=2/backscatter’)

radiance=codes_get(m,’/channelNumber=45/radiance’)

14th MOS Workshop – 20th November 2014 Slide 16

One single get function for all message types

Clear text identifiers

Tree like / hierarchical access

Array is returned. Dynamically allocated in FORTRAN

Slide 17

ecCodes design

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Decoding engine

Decoding rules

(TEXT FILES)

Message

User interface

dewPointTemperature

17.5

Hand written (error prone)

Automatically generated from publicly available source shared with other decoders

Meaning publicly available on web

Web accessible registry

codes.wmo.int

1. Source of meaning for the user

2. Provides automatic generation of the decoding rules

Slide 18

ecCodes messages and bindings

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ecCodes

GRIB1

GRIB2

BUFR

METAR

FORTRAN

C

Python

Perl

? ?

TAF

GTS

Tools

Slide 19

ecCodes coming soon

Under development, currently in a prototype stage Beta version will be available soon from

software.ecmwf.int Back compatible with grib_api

14th MOS Workshop – 20th November 2014 Slide 19