The AMDAR Observing System Mexico AMDAR Regional Workshop, 8-10 November 2011 Dean Lockett Observing Systems Division, WMO.

The AMDAR Observing System

Mexico AMDAR Regional Workshop, 8-10 November 2011

Dean LockettObserving Systems Division, WMO

Content

1. The WMO Aircraft Observations System

2. What is AMDAR?

3. The AMDAR Observing System

4. Global AMDAR System Current Status

5. Global AMDAR Coverage

6. Why Develop an AMDAR Programme?

7. Getting Started:• AMDAR Reference Manual• AMDAR Software

Observations From Aircraft- Aviation Operations Reports

• Pilot reports – PIREP– Report of actual weather conditions in-flight

• Aircraft Reports – AIREP– Standard format report that can be used to relay

weather information• Meteorological observations: wind, air

temperature, cloud amount, cloud cover, cloud base and cloud top, and special phenomena

• Automated Dependent Surveillance – Contract and Broadcast (ADS-C and ADS-B)– Essentially automated aviation industry reports that

can have a meteorological report included.

Observations from Aircraft- Meteorological

• Processing, formatting and relay of aircraft observations commenced in the 70s in research mode;

• Automated measurement programs for operational meteorology commenced in the late 1970s with ASDAR– ASDAR = Aircraft Satellite DAta Relay– Sensor and communications package.– Largely indendent of aircraft infrastructure and avionics– Forerunner to modern day TAMDAR by AirDat.

• Research programs concluded: met. data from aircraft sensors provided very high quality data (air temperature, winds, air pressure, position) as ASDAR and even radiosonde systems.

• Other sources of aircraft data include:– 3rd party avionics systems such as the AeroMechanical Services

(AMS) AFIRS.– Mode S (ADS-B)– TAMDAR

• AMDAR…

Aircraft Observations

AviatonAviatonSourcesSources

AIREP, PIREPAIREP, PIREPADS-C/BADS-C/BMode SMode S

3rd Party3rd PartyAMS AFIRSAMS AFIRS

3rd Party3rd PartyTAMDARTAMDAR

Met. SourcesMet. SourcesAMDAR + WVAMDAR + WV

Met. SourcesMet. SourcesAMDAR AMDAR

Aircraft Aircraft ObservationsObservations

No sensor No sensor deploymentdeployment

Sensor Sensor deploymentdeployment


• AMDAR = Aircraft Meteorological DAta Relay– WMO affiliated observations program under the World

Weather Watch Programme.– Automated relay of aircraft meteorological data according to

WMO and NMHS meteorological specification.– Program enabled with innate sensors, avionics and

communications systems (ACARS).– Data collected in (near) real-time on ascent and descent

(vertical profiles) and en-route according to meteorological requirements.

– Quality of data equivalent to meteorological radiosonde (balloon-borne sensors).

– Over 30 airlines and around 2800 aircraft participating.


• High resolution vertical profiles (i.e. measurement taken regularly, e.g. every 10hPa or 100m on ascent or descent) of:– air temperature,– wind speed and direction– when available, water vapour content and icing;

• Regular reports (e.g. every 5-10 minutes) of the same meteorological variables whilst en-route at cruise level;

• Accurate measurement of coordinates (time, latitude, longitude and pressure altitude);

• Measurement of turbulence:– DEVG (Derived Equivalent Vertical Gust); and/or,– EDR (Eddy Dissipation Rate: a meteorological turbulence parameter

appropriate for direct assimilation into numerical weather models);– Icing (on or off)

• Measurements are compiled into a standard message format and transmitted to the Meteorological Agency in as near-to real-time as possible.


• Software implemented in aircraft avionics;

• Transmission by VHF or satellite communications to ground station;

• Relayed by a Data Service Provider to Airline (or direct to Met. Service);

• Data decoded used by Met. Service;

• Data is distributed on the GTS.

The AMDAR Observing SystemData Quality

Variable Uncertainty Temperature ±1.0 C

Wind Vector ±2-3 m/s

Pressure Altitude ±4 hPa

Jetstar Asia Aircraft: 9V-JSA; Profile: Ascent VHHH; Date/Time: 9/4/2011 1247 UTC; Comparison: Air TemperatureRadiosonde: Kings Park 9/4/2011 1200 UTC

0

2000

4000

6000

8000

10000

12000

-40 -30 -20 -10 0 10 20 30

Degrees C

Alt

itu

de

(m)

AMDAR Radiosonde

The AMDAR Observing SystemData Quality

Jetstar Asia Aircraft: 9V-JSA; Profile: Descent VHHH; Date/Time: 8/4/2011 0213 UTC; Comparison: Wind SpeedRadiosonde: Kings Park 8/4/2011 0000 UTC

0

2000

4000

6000

8000

10000

12000

0 5 10 15 20 25 30 35 40 45

Knots

Alt

itu

de

(m)

AMDAR Radiosonde

Global Aircraft Data– Daily Output

Aircraft Data - Coverage

Courtesy of Courtesy of NOAA/ESRL/GSDNOAA/ESRL/GSD

5% of available obs 5% of available obs shownshown

Status of RBSN Upper Air Network

Why Should a Met. Service Develop an AMDAR Programme?

• Improvement in upper air coverage:– Source of high quality upper air data;– AMDAR can provide superior temporal coverage of

winds and air temperatures to radiosondes (potentially hourly versus 12-hourly);

– No sensor implementation required – AMDAR facilitated by software deployment;

– Cost of AMDAR profile can be 1/10th to 1/100th cost of radiosonde profile.

– Opportunity to redesign upper air observations networks for efficiency!!!

Why Should a Met. Service Develop an AMDAR Programme?

• Experience with use of AMDAR data has shown that:– Impact on Numerical Weather Prediction is positive

and significant; [Input to Aviation Forecasting…]– Extremely useful for input to forecast applications:

• Surface and upper air forecasts of wind and temperature;• Thunderstorm genesis, location and severity;• Wind shear location and intensity;• Low cloud formation, location and duration;• Fog formation, location and duration;• Turbulence location and intensity;• Jetstream location and intensity.[Input to Aviation Forecasting…]

Why should airlines participate in the AMDAR Programme?

• Weather accounts for 70% of all air traffic delays within the U.S. National Airspace System (NAS)….

• Further, the Federal Aviation Administration (FAA) has determined two thirds of this is preventable with better weather information.

- From: USA, FAA NextGen: Congressionally mandated initiative to modernize the U.S. Air Transportation System

• "A key finding, based on an analysis of several 2005-2006 convective events, is that as much as two-thirds of the weather-related delay is potentially avoidable."

- Research, Engineering and Development Advisory Committee; Report of the Weather-ATM Integration Working Group; Oct3, 2007.


• NextGen:– “The total cost of domestic air traffic delays to the

U.S. economy was as much as $41 billion for 2007.”

– Air-traffic delays raised airlines' operating costs by $19 billion.

– Delays cost passengers time worth up to $12 billion.

– Indirect costs of delay to other industries added roughly $10 billion to the total burden

Two thirds of 70% of $19,000,000,000 is a number Airlines should be interested in!


• AMDAR Impact on Weather Service Operations: Improved Numerical Weather Prediction Improved forecasting abilitySensor monitoring ability for Aircraft

Sensor Monitoring for Aircraft

Aircraft Daily Mean Air Temperature Bias Against Numerical Model

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

4/11/2005 14/11/2005 24/11/2005 4/12/2005 14/12/2005 24/12/2005 3/01/2006 13/01/2006 23/01/2006 2/02/2006 12/02/2006

Day

Air

Tem

pera

ture

Bia

s (

C)


• AMDAR Impact on Weather Service Products: Improved NWP and Forecast ability:

Improved Aviation Products

Sensor monitoring ability:Provide sensor monitoring service to airlines


• AMDAR Impact on Airline operations: Improved Aviation Products:

Improved safety mangement Improved flight operations

Provide sensor monitoring service to airlines: Improved aircraft management


• AMDAR Impact on Airline Performance: Improved safety mangement => Safety Record => $Savings Improved flight operations => Customer Satisfaction =>

$Savings Improved aircraft management => Better fuel use =>

$Savings

Getting Started – AMDAR Reference Manual

AMDAR Reference ManualWMO-No. 958

• Chapter 1.– Provides background and history on the AMDAR Program;

• Chapter 2. Sensors and Measurements:– Aircraft sensors utilised for basic measurements:

• Pitot Static Head (static air pressure)• Total Air Temperature probe (total air temperature)• Inertial Reference Unit and or GPS for positional information

– Derived information (Air Data Computer): • Pressure altitude (ICAO);• (Static) Air Temperature;• Latitude, longitude;• Wind speed and direction;• Vertical acceleration (for turbulence);• Roll angle;• Mach no. required for corrections;

• More detailed information in Appendix I


• Chapter 3: – Onboard message Compilation

• Chapter 4:– Data content and downlink formats– Sampling on ascent and descent and

enroute

• More detailed information in Appendices 2 and 3:


• Chapter 5: AMDAR Data Management (by NMHS):– Data decoding and processing;– Formats for GTS dissemination:

• FM42 (text)• FM94 BUFR (binary)

• Chapter 6: Data Quality Control Processing (by NMHS)– Real-time quality control (before GTS dissemination);

• Basic range and consistence checks

– Quality monitoring;• Near real-time (sensor issues);• Long-term, e.g. monthly (sensor issues, systemic issues)

• More detail in Appendix 4

AMDAR (Aircraft) Observations Software Standards

• Two main standards:– AAA (ACARS ACMS AMDAR) specification

• Implemented mainly in Teledyne ACMS systems.

– ARINC 620 versions 1 through 4.• Implemented mainly in Honeywell/Rockwell Collins

systems.

• Both have similar meteorological and functional definition.

• Both have uplink control functionality, which is crucial to AMDAR Programme operation and viability (for redundant data and communications costs reduction)

Summary

1. AMDAR Observing System is an Aircraft Observations system specified and developed for meteorological purposes.

2. Other aircraft observations supplement AMDAR data.

3. AMDAR quality is equivalent to radiosonde quality and much less expensive.

4. AMDAR Programme is mutually benificial to Met. Services and Aviation.

5. Introduced to AMDAR Reference Manual, WMO-No. 958.

6. Avionics Software standards exist and should be utilised for AMDAR Programme development.

Thank you.

The AMDAR Observing System Mexico AMDAR Regional Workshop, 8-10 November 2011 Dean Lockett Observing Systems Division, WMO.

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