Advanced Acoustic Model (AAM) Software
About AAM
The Advanced Acoustic Model (AAM) is a suite of software tools that allows users to model vehicle sound levels at receiver positions, either on a uniform grid or at specific defined locations, from helicopters, tiltrotor vehicles, and fixed wing aircraft.
AAM is flexible in its ability to allow users to model noise from any traditional or evolving transportation noise source.
A variety of noise metrics are calculated by the model. Acoustic properties of the noise sources are defined by sets of sound spheres, each sphere being centered on a noise source of the aircraft, or as a single compact source at the center. Sets of sound spheres may include one-third octave band (broadband) levels, or via narrow band, 1/12 octave band or as pure tone sound pressure levels and phase. Noise contours on the ground may be output graphically or in tabular format.
Results are in a form suitable for inclusion in environmental documents or for computing other conditions such as human audibility in the presence of background sound.
Instructions
- Fill out and submit the online AAM Software Request Form. If you have technical difficulties with the online form, you may complete a fillable PDF software request form and submit it via email to AAM_support@DOT.gov. Requestor should be at a level commensurate with the software access needs (i.e., Individual for single user access, group leader for group access).
- Indicate if it is OK to contact you at the email address(es) you provided regarding AAM software and training updates.
- If approved*, you will receive an email with instructions for accessing the installation package at the email address that you provided in the Software Request Form. We are currently using Huddle for software distribution, and access for the AAM download is free.
* AAM v3 is available publicly to individuals and entities located in the United States in compliance with all relevant export laws and regulations of the United States. International release of the AAM software is pending.
AAM License Agreement
Please review the AAM License Agreement.
Resources
- AAM Software Frequently Asked Questions
- BaseOps
- Tecplot Focus (Note: Recommended for sphere development using ART, but not necessary)
Articles and Videos About AAM
- Volpe press release: NASA Transfers the Advanced Acoustic Model (AAM) to the U.S. DOT Volpe Center
- Volpe Annual Accomplishments – January 2019, “Mapping Quarry Noise for the Oregon Department of Transportation,” page 31
- Fly Neighborly AAM-based Acoustic Animations: Fly Neighborly YouTube channel
- AAM Fly Neighborly Hamptons Video
- Uber Summit UAM modeling using AAM (starts at 19:00)
- Fly Neighborly Operational Noise Abatement Procedures Developed using AAM Analysis
- Joint NASA-Volpe Internoise Paper Describing a QuadRotor Analysis
- Internoise 2021 AAM Animations
AAM Support Contact Information
AAM_Support@dot.gov
617-494-2372
Advanced Acoustic Model Support, 55 Broadway V-324, Cambridge MA 02142
- NASA
- U.S. Department of Defense (Army, Air Force, and Navy)
- Oregon Department of Transportation
- Uber Elevate
In the late 1990s, NASA sponsored Wyle Laboratories for the development of the Rotorcraft Noise Model (RNM), a research tool for modeling tiltrotor aircraft, such as the XV-15, in order to develop low noise operational procedures. Over the next few decades, under NASA technical oversight and funding, the code was expanded to model conventional helicopters, and the Acoustic Repropagation Technique (ART) model was improved in order to obtain empirical noise spheres from acoustic flight test measurement data.
RNM was adopted by the Department of Defense (DOD) and adapted to work with the BaseOps software for modeling helicopter noise in support of National Environmental Policy Act (NEPA) analysis for DOD facilities. The U.S. Navy funded the addition of terrain modeling in RNM in the early 2000s. Subsequent research in high thrust military aircraft funded by the Strategic Environmental Research Defense Program (SERDP) led to the adaption of RNM into the Advanced Acoustic Model with the addition of fixed-wing (including thrust vectoring capable) aircraft.
In 2017, an ArcGIS-based framework was developed for the Oregon Department of Transportation to model the noise from aggregate source sites (quarries) using AAM as the propagation model. A companion noise source database that includes a wide variety of ground-based equipment was also developed for use with the Quarry Noise Model (QNM). The QNM interface may also be used to build terrain, ground cover impedance, and foliage files for use in AAM.
The Uber Elevate project sponsored the continued improvement of AAM to include capabilities for acoustic modeling of the new genre of advanced air mobility and urban air mobility transportation vehicles and to facilitate research into the prediction of community acceptance. New features added to AAM include the capability to model 1/12 octave band noise spheres and expansion of the ART process for developing 1/12 octave band spheres from acoustic flight measurements.
In collaboration with other Uber partners, the capability for computing time varying loudness (TVL) against spatially varying backgrounds was added to the AAM run stream and integrated into the 3DVisualizer software for rendering TVL acoustic animations.
In March 2020, after providing more than two decades of sponsorship, development vision, and technical oversight, NASA completed the transfer of legal ownership of the Advanced Acoustic Model to the Volpe Center.