Development of Improved Ambient Computation Method in Support of the National Parks Air Tour Management Act

摘要

Approximately 85 National Park units with commercial air tours will need Air Tour Management Plans (ATMPs). The objective of an ATMP is to prevent or mitigate significant adverse impacts to National Park resources. Noise impacts must be characterized in relation to representative baseline ambient sound levels. Computing ambient sound levels for acoustic conditions in National Parks is not straightforward. The National Park Service and Federal Aviation Administration, both supported by the Volpe Center, are evaluating current methods and developing standards for computing ambient sound levels in National Parks. This report describes the results of several on-going analyses: (1) Analysis of ambient data measured under high-wind conditions; (2) Quantification of the differences between in situ observer logging versus offline review of digital recordings; and (3) Computation of natural ambient and existing ambient without air tours.