REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. 1. AGENCY USE ONLY 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED (Leave blank) December 1997 Final Jan 93 - Dec 97 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Integrated Noise Model (INM) Version 5.1 Technical Manual FA765/A7012 6. AUTHOR(S) Gregg G. Fleming1, Jeffrey R. Olmstead2, John R. D'Aprile1, DTFA01-93-C-00078 Task Orders 9,14,19 Paul J. Gerbi4, John M. Gulding3 (Program Manager), Jake A. Plante3 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION 1 U.S. Department of Transportation 2 ATAC Corporation REPORT NUMBER Research and Special Programs Administration 757 North Mary Avenue John A. Volpe National Transportation Systems Center Sunnyvale, CA 94086 Acoustics Facility, DTS-75 Kendall Square Cambridge, MA 02142-1093 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING 3 U.S. Department of Transportation AGENCY REPORT NUMBER Federal Aviation Administration Office of Environment and Energy 800 Independence Avenue, S.W. FAA-AEE-97-04 Washington, DC 20591 11. SUPPLEMENTARY NOTES 4 Unisys Corporation Kendall Square Cambridge, MA 02142 12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE This report is part of the INM 5.1 software release. 13. ABSTRACT (Maximum 200 words) The Federal Aviation Administration, Office of Environment and Energy (FAA, AEE-120) has developed Version 5.1 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. The Technical Manual for INM 5.1 describes the flight-path methodology (Chapter 2), along with the basic methodology employed by the INM to compute a noise-level or time- above metric at a single, user-specified observer, or at an evenly-spaced, regular grid of observers (Chapter 3). The noise/time computation methodology is presented in a concise step-by-step fashion, and includes a description of: (1) the computation of the flight-segment geometric and physical parameters; (2) the flight-segment noise-level interpolation process; (3) the acoustic impedance adjustment; (4) the flight-segment noise-fraction adjustment for exposure-based metrics; (5) the airspeed adjustment for exposure-based metrics; (6) the lateral attenuation adjustment; (7) the ground-based directivity adjustment for observers behind start-of-takeoff-roll, as well as for computing metrics associated with runup operations; (8) the metric computation process; and (9) the development of a recursively-subdivided irregular grid methodology, which is used for computing noise contours (Chapter 4). 14. SUBJECT TERMS 15. NUMBER OF PAGES Airport Noise, Computer Model, Noise Contours, Integrated Noise Model, 112 INM, Noise-Level Prediction, Noise-Level Metric, Day-Night Average Sound Level, Ldn, Heliport Noise Model, FAR Part 150 16. PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF REPORT OF THIS PAGE OF ABSTRACT Unclassified Unclassified Unclassified NSN 7540-01-280-550 Standard Form 298 (Rev. 2-89) Prescribed by ANSI Std. 239-18 298-102 INM 5.1 Technical Manual PREFACE This document was jointly prepared by the John A. Volpe National Transportation Systems Center, Acoustics Facility (Volpe Center), and the ATAC Corporation, in support of the Federal Aviation Administration, Office of Environment and Energy (FAA AEE-120). It is a Technical Manual for the FAA's Integrated Noise Model (INM) Version 5.1 computer software used to predict noise impact in the vicinity of airports. The INM 5.1 Technical Manual presents the methodology employed by INM 5.1 to build aircraft flight paths, and to compute noise-level and time-above metrics based upon the finite flight-segment information. DISCLAIMER The contents of this report reflect the views of the Volpe Center and the ATAC Corporation, and they are responsible for the facts and accuracy of the material presented herein. The contents do not necessarily reflect the official views or policy of the U.S. Department of Transportation. This INM Technical Manual does not constitute a standard, specification, or regulation. The design, production, and distribution of this manual has been paid for entirely from user fees. i INM 5.1 Technical Manual ii INM 5.1 Technical Manual TABLE OF CONTENTS Chapter Page PREFACE .................................................................... i DISCLAIMER ................................................................ i LIST OF FIGURES ........................................................... vii LIST OF TABLES ............................................................viii 1 INTRODUCTION .......................................................1 1.1 Grid-Point Computations .............................................1 1.2 Metric Families ....................................................2 1.3 Metric Types ......................................................2 1.3.1 Exposure-Based Metrics .......................................2 1.3.2 Maximum Noise Level Metrics ...................................4 1.3.3 Time-Above Metrics ..........................................4 1.4 Terminology .......................................................5 1.5 Abbreviations .....................................................12 2 FLIGHT-PATH COMPUTATION METHODOLOGY ..........................13 2.1 Summary of Input Data for Noise Computation ............................13 2.1.1 Airport Information ..........................................13 2.1.2 Aircraft Information ..........................................14 2.1.3 Observer Information .........................................14 2.1.4 Noise Metric Information ......................................15 2.2 Noise-Power-Distance Input Data .....................................16 2.2.1 NPD Data Sets .............................................16 2.2.2 Maximum Noise Level Approximation ............................17 2.2.3 NPD Data Development Criteria ................................17 2.3 Flight Profile Calculation .............................................18 2.3.1 Profile Point Input Data .......................................18 2.3.2 Procedure Step Input Data .....................................19 2.3.3 Non-ISA Model for Atmospheric Ratios ..........................20 2.3.4 Corrected Net Thrust Per Engine For Departure .....................21 2.3.5 Takeoff Ground Roll Segment ..................................22 iii INM 5.1 Technical Manual 2.3.6 Touch-and-Go Power-On Ground Roll Segment ....................24 2.3.7 Climb Segment ..............................................25 2.3.8 Acceleration Segment .........................................28 2.3.9 Descent Segment ............................................30 2.3.10 Level Segment ..............................................31 2.3.11 Cruise-Climb Segment ........................................32 2.3.12 Landing Segment ............................................32 2.3.13 Decelerate Segment ..........................................33 2.4 Flight Path Calculation ..............................................33 2.4.1 Ground Track Processing ......................................34 2.4.2 Circular Arc Conversion .......................................34 2.4.3 3-D Flight Path Construction ...................................35 2.4.4 Displaced Thresholds and Threshold Crossing Heights ................36 2.4.5 Touch-and-Go and Circuit Flight Path Methods .....................36 2.4.6 Segments Too Short and Too Long ..............................37 3 ACOUSTIC COMPUTATION METHODOLOGY .............................39 3.1 Flight Path Segment Parameters .......................................41 3.1.1 Closest Point of Approach and Slant Range ........................43 3.1.2 Speed, Altitude, Distance, and Power .............................44 3.2 Noise Level Interpolation (LP,d) ......................................46 3.2.1 Exposure-Based Noise Level Metrics .............................47 3.2.2 Maximum Noise Level Metrics ..................................48 3.3 Acoustic Impedance Adjustment (AIADJ) ................................48 3.4 Noise Fraction Adjustment for Exposure-Based Metrics (NFADJ) ..............50 3.4.1 Observer Behind, Astride, Ahead of Segment .......................50 3.4.2 Observer Behind Start-of-Takeoff Roll ............................53 3.5 Airspeed Adjustment for Exposure-Based Metrics (ASADJ) ...................54 3.6 Lateral Attenuation Adjustment (LAADJ) .................................54 3.6.1 INM