Integrated Noise Model (INM), Version 5.0 (FAA) (Last update: 8/29/96 JKK)
1. Primary Model Category
Modeling and Display of Aircraft Community Noise Impact.
2. Summary
INM is an empirical tool used to calculate the noise impact around airports. The noise levels are based on a series of stored noise profiles of different aircraft under different flight conditions such as weight and trip length. The model has recently been enhanced (Version 5.0) to include a number of new capabilities.
3. Input Requirements
Requires an aircraft flight profile, including aircraft type, flight plan, and trip length (gross weight). Data may be entered using a graphical user interface using Windows. Geographical Information System (GIS) overlays can be used to show impact on population and topography. The model includes navigational aid data for the entire U.S. and can also incorporate ARTS radar data to examine actual trajectories. Official Airline Guide (OAG) data can also be used to examine traffic schedules and fleet mixes.
4. Outputs
A Graphical User Interface is also used for analysis of the results. INM displays the community noise impact as a series of noise contours in Noise Exposure Forecast (NEF), Equivalent Sound Level (Leq), Day-Night Average Sound Level (Ldn), and Time Above a specified threshold of A-Weighted Sound (TA). The model calculates the total area exposed to different noise levels, and the population exposed to different noise levels. A differencing feature is included to allow the comparison of two different operating conditions on noise impact.
5. Major Assumptions
The trajectory of the aircraft can be modeled as a series of straight and constant-radius curved segments or can be specified using actual ARTS data or through OAG schedules. Noise information is stored as intensity directly below the path of the aircraft. Sideline noise measurements are calculated using a lateral attenuation factor that is a function of the aircraft's height and azimuth above the ground. The model can be used to examine single or multiple events, and can include lateral dispersion of flight tracks. Wind is not included as a parameter.
6. Computational Characteristics
Code exists for Windows NT (recommended) and Windows V3.1 for PCs. Minimum specifications are: 486DX 66MHz processor, Microsoft Windows NT (V3.5) with 35 MB RAM or Windows V3.1 with 16 MB RAM, 640x480 16 color VGA display, mouse input device, 3.5" 1.44 MB floppy disk drive, 300 MB hard drive (INM requires 20 MB, each study requires 1-30 MB), CD-ROM drive for terrain and census data processing (optional).
7. Modularity and Flexibility
INM is a stand-alone analysis tool and would not be easily ported or incorporated in a larger software package.
8. Status
The model is the FAA standard for calculating aircraft noise impact.
9. Extent of Model Verification
The empirical data used in the model has been verified through an extensive testing program.
10. Principal Applications
Calculation of the noise impact (in terms of area and population) for a single aircraft for a single event or a mix of aircraft over an extended period. Includes lateral dispersion of flight tracks, flexible aircraft profile generation, graphical track construction, and expanded visual analysis.
11. Availability
Available for $250 from the FAA. Contact: John Gulding, INM 5.0 Program Manager, (202)-267-3654.
12. Information for Model Evaluation
User's Guide for INM (V3.0); V 5.0 press release; communication with Donna Warren, FAA.
13. Summary Evaluation
INM is the FAA standard noise prediction tool. It assumes that aircraft will fly trajectories that can deviate from specified flight plans or can use ARTS trajectory data. It is limited in its ability to predict the variability in noise impact that could occur due to wind conditions, but is flexible in terms of analyzing operating procedures and fleet mixes. INM has improved graphical interfaces for both data entry and visual analysis of the results.
13. Summary Evaluation
INM is the FAA standard noise prediction tool. It assumes that aircraft will fly trajectories that can deviate from specified flight plans or can use ARTS trajectory data. It is limited in its ability to predict the variability in noise impact that could occur due to wind conditions, but is flexible in terms of ana485e a three day wkd that it would be a good idea if we planed at least a one day trip to near by retreat. If anyone is interested let me know. I am thinking of a trip to newport in particular. Back after popular demand.
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