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This article provides an update on the FAA's EDR Reporting Program, focusing on the need for automated turbulence reports. It discusses the challenges of using pilot reports and introduces the In situ Turbulence Measurement and Reporting System as a solution. The article also explores the debate between using EDR and RMS-g as turbulence metrics and explains their relevance in different scenarios. Additionally, it showcases the benefits of EDR reports compared to traditional pilot reports and highlights future activities and airline participation in the program.
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An Update on the FAA’s EDR Reporting Program Larry Cornman National Center for Atmospheric Research
The Need for Automated Turbulence Reports • Turbulence can be a very dynamic and spatially localized phenomena – hence the need for real-time measurements. • Pilot reports are problematic in that they are subjective measures of the aircraft response to the turbulence – not quantitative measures of the atmosphere.
In situ Turbulence Measurement and Reporting System Goal: To augment/replace subjective PIREPs with objective and precise turbulence measurements. Features: • Atmospheric turbulence metric: eddy dissipation rate (EDR). • EDR can be scaled into aircraft turbulence response metric (RMS-g). • Adopted as ICAO Standard
EDR vs. RMS-g? • EDR is a measure of the turbulent state of the atmosphere. • RMS-g is the response of a given aircraft – at a given flight condition – to the turbulence. • Both are valid quantities, the issue is what is the appropriate/best use of them?
EDR vs. RMS-g? • Reporting EDR from an aircraft requires no additional information. • Reporting RMS-g from an aircraft requires information on aircraft type, altitude, weight, and airspeed.
EDR vs. RMS-g? • Forecasters, models, scientists want EDR. • Pilots would probably want RMS-g. • ATC, Dispatch: Since they are talking to a number of users at a time, do they want aircraft specific, or aircraft independent measure? • Maintenance would want peak-g.
EDR vs. RMS-g? • Given knowledge of aircraft type, airspeed, altitude and weight, EDR can be converted into RMS-g with sufficient accuracy.
Conversion Between EDR and RMS-g: Illustrated with Data from NASA B-757 Aircraft 2407 one-minute samples Measured RMS-g Median median r=0.94 m=0.98 EDR-predicted RMS-g peak r=0.95 m=1.03 Peak
EDR vs. RMS-g? • FAA/NCAR position is: Use EDR as the reporting metric for air-ground, air-air, and ground-air. If a given user wants RMS-g, convert EDR at their location.
Increase inSpatial/temporal Coverage: UAL EDR ReportsCompared to pireps 1.3 million EDR reports/month from 100 or so aircraft - compared to 55k pireps from all aircraft. 737 757 737 + 757
EDR on Experimental ADDS • Display contains EDR reports, pireps, GTG. • Movie loops, cross-sections, etc…
Major Upcoming Activities • SWA implementation in CY06/07. • Status: preliminary software has been delivered to Honeywell, who is doing integration and testing. SWA Route Structure
GTG Status GTG1/ADDS Example • GTG1 • On “Operational ADDS” since March 2003 • CAT above FL200 • Based on RUC 13/20 • Forecasts out to 12 hrs • GTG2 • On “Experimental ADDS” since Nov 2004 • Improved turbulence diagnostics • “CAT” above FL100 • Based on RUC 13/20 • Forecasts out to 12 hrs • Textual representation • Includes UAL in situ EDR measurements above FL200 GTG2/EDR GTG2/PIREPS
Future Airline Participation • Discussions ongoing with Delta Airlines. • Discussions begun with Northwest Airlines. Future work is contingent on continued FAA funding…
Other Issues • Cost/Optimization • Since turbulence can be highly-localized and temporally dynamic, having as many measurements (even null) as possible is important. But this has to be balanced by cost considerations. • Event-based reporting is a partial, though not optimal, solution (what happened between the events?)
Other Issues, cont’d • Resolving the EDR vs. RMS-g issue and international harmonization: • ICAO standard is EDR. • TAMDAR uses EDR. • Will all US carriers use EDR? • AMDAR does not use EDR.