Airports will soon be required to use FAA’s Aviation Environmental Design Tool (AEDT) when conducting airport noise studies (e.g., FAR Part 150 studies, Environmental Impact Statements, Environmental Assessments). AEDT uses a method that assumes noise propagation only over “soft” ground surfaces in the calculation of lateral attenuation, based on SAE-AIR-5662, Method for Predicting Lateral Attenuation of Airplane Noise (2012). In reality, areas around airports are often covered with a variety of ground types (e.g., “hard” or reflective ground, such as large areas of pavement or water), which can affect noise levels around an airport. By ignoring effects from multiple ground types, AEDT may under-predict the noise from aircraft operations. Research is needed to develop a method to account for impedance variability of ground surfaces to improve the noise prediction accuracy of AEDT.
The objective of this research is to develop a method to account for impedance variability of ground surfaces in a manner suitable for model implementation to improve the noise prediction accuracy of AEDT.
The final deliverables will include:
(1) A technical report documenting the entire research effort, including the research methodology, results, and a prioritized list of additional related research needs;
(2) Detailed documentation of model improvements (e.g., process map, equations, data, validation and verification) to address impedance variability of ground surfaces to improve the noise prediction accuracy of AEDT; and
(3) A supplement to the AEDT User Guide to help practitioners incorporate the effect of impedance variability of ground surfaces. The supplement should describe input data, the modeling method, and generation and interpretation of results. The supplement should also assist practitioners in determining whether incorporating impedance variability of ground surfaces is appropriate for their particular noise study.
Research is complete. Results are published in ACRP Web-Only Document 32.