1 mexico regional amdar workshop november 2011 data quality monitoring and control (qm / qc) axel...

1Mexico Regional AMDAR WorkshopNovember 2011

Data Quality Monitoring and Control (QM / QC)

Axel HoffConvenor of WMO AMDAR Panel‘sScience and Technical Sub-Group

Deutscher Wetterdienst (DWD)German Meteorological ServiceDivision: Measurement Technology, TI 22Frankfurter Strasse 13563067 Offenbach am MainGermany


Which features of the AMDAR data have to be monitored and controlled ?

– Quality• Data transmission (format, validity, ...)• Physical features (bias, RMSE, ...)

– Amount • Statistics about frequency in space and time• Targeting, optimisation

– Timeliness• Transmission delays


Interested PartyParameter Airlines AMDAR

ATM __

Navigation Data Position (Precision) ± 30 m X X Groundspeed Vector ± 2 m/s X True Heading (Precision) ± 0.1 ° X

Air Data Primary Air Data

- Static Pressure ± 1 hPa X X- Total Pressure ± 1 hPa X- Temperature ± 1 K X X- Humidity ± 1 % RH in future ? X

Secondary Air Data- True Airspeed ± 2 m/s X- Wind vector ± 2.5 m/s X X

What are the quality requirements ?

RVSM

AMDAR is the freeloader of the air traffic’s requests


What does AMDAR’s Quality Management consist of ?

– Real-Time Quality Control• At the measurement stage on board• At the code conversion for GTS• At the assimilation stage for numerical forecast

– Quality Evaluation for long-term behaviour• Systematic biases• Trends and drift effects


AMDAR Data Management


• Observing Platform (Aircraft)– Data sampling – Online calculation of the final parameters– Basic QC (plausibility checks)– Transmission to ground

Where do we find QM / QC in AMDAR ?


• Communication Service Provider(e.g. ARINC or SITA)– Relay observations to ground network (downlink)

(airline or Data Reception and Switching Centre) – Transmit uplink commands to aircraft



• Data Reception and Switching Centre (DRSC)– Real-time QC – Passing the data via GTS to all participating

institutions– Reporting to System Manager and QEv Centre



Real-Time QC:– Check for transmission errors– Check for duplicates– Range check

• Values to be within plausible limits

– Position and time check in time series from single aircraft

– Check against reject list of QEv Centre


• Data Assimilation and Numerical Modelling Centre– Assimilation of the AMDAR data– Identify outliers, sensor biases, RMS errors

by checking against the model’s “first guess” fields



• Quality Evaluation Centre– Near-real-time checks– Update reject lists– Reporting to System Manager and/or DRSC



Near-Real-Time Check: – If not already done in real-time checks

• Transmission errors• Duplicates• Range (values to be within plausible limits)• Consistency in position and time

in time series from single aircraft

– Timeliness– Identify observing platforms appearing with

biases, drifts, scattering phenomena


• System Manager– Manage programme (incl. status reports, etc.)– Manage data optimization and targeting– Initiate QC actions (notify airline of bad data)– Coordination with other AMDAR programmes in the

neighbourhood and worldwide



• Airlines– Implement and operate AMDAR functionality modules

(on-board software, humidity sensor, ground software)– Support up-link control for external commands– Forward measurement data reports to DRSC– System repair on aircraft reporting erroneous data



• External AMDAR Programme– Insert data on GTS– Disseminate QM reports and statistics



• Monitoring Centres– Publish quality statistics– Provide regular platform reject lists



• AMDAR Panel Technical Coordinator– Coordinate AMDAR management and development

within WMO AMDAR Panel– Coordinate quality reporting activity



• Data Archiving Centre– Access all AMDAR GTS data from the DRSC– Eliminate duplicates– Flag data having quality deficits– Archive data in databases– Publish data catalogues



• QC Forum– Provide network for interchange and discussion of

data management issues, problems, reports, actions, and initiatives



Exemplary Results from NOAA Observations compared to GSI background (num. model)

Relative Humidity Biases to BG - NA Area August 2011

-10 -8 -6 -4 -2 0 2 4 6

1000

925

850

700

500

400

300

Pre

ssu

re in

hP

a

RH Biases in %

TAMDAR

ACARS

Sondes


amounts and timeliness, daily trend

timeliness, distribution for all E-AMDAR aircraft

Exemplary Results from E-AMDAR Amounts and Timeliness


Exemplary Results from E-AMDAR Observation minus first guess of HIRLAM

distribution for all E-AMDAR aircraft

Daily trend

Temperature Bias


Exemplary Results from E-AMDAR Mean daily biases in temperature and wind


Exemplary Results from E-AMDAR Identification of outlying aircraft and single events


AMDAR’s quality control gives vital feedback for both

– Meteorological Servicesto

• sort out erroneous data sources• learn for assimilation strategies

– Airlinesto identify aircraft with problems in

• pressure measurement ( altitude’s accuracy)• temperature measurement ( engines)• true airspeed / wind ( range calculation)


Questions ?

1 mexico regional amdar workshop november 2011 data quality monitoring and control (qm / qc) axel...

Documents

amdar programmes

data assimilation

data reception

data optimization

data quality monitoring

qev centrerealtime qc

centre drscrealtime

external amdar programmeins