FAA-AEE-02-01

Manual

United States

John A. Volpe National Transportation Systems Center (U.S.)

NTL-AVIATION-Aviation Energy and Environment ; AGR-IMPACTS-Environment ; NTL-ENERGY AND ENVIRONMENT-Environment Impacts ; NTL-ENERGY AND ENVIRONMENT-Aviation Energy and Environment ;

The Federal Aviation Administration, Office of Environment and Energy (FAA, AEE-100) has

developed Version 6.0 of the Integrated Noise Model (INM) with support from the John A. Volpe

National Transportation Systems Center, Acoustics Facility (Volpe Center) for development of the

acoustic computation module, and from the ATAC Corporation for systems integration, development

of the graphical interface, and methods for computing aircraft flight profiles and constructing

flight paths, which are processed by the acoustics module.

This Technical Manual describes the core technical components in INM 6.0, including the flightpath

methodology (Chapter 2), along with the basic methodology employed by the INM to compute

noise levels or time-above metrics at a single, user-specified observer, or at an evenly-spaced,

regular grid of observers (Chapter 3).

The noise/time computation methodology includes a description of: (1) computation of the flightsegment

geometric and physical parameters; (2) flight-segment noise-level interpolation process;

(3) atmospheric absorption adjustment; (4) acoustic impedance adjustment; (5) flight-segment

noise-fraction adjustment for exposure-based metrics; (6) aircraft speed adjustment for

exposure-based metrics; (7) lateral attenuation adjustment; (8) ground-based directivity

adjustment for observers behind start-of-takeoff-roll, as well as for computing metrics

associated with run-up operations; (9) metric computation process; and (10) development of a

recursively-subdivided irregular grid methodology, which is used for computing noise contours

(Chapter 4).

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Volpe National Transportation Systems Center, Technical Reference Center