An active space is a well-known concept in bioacoustics (Marten and Marler 1977). It represents a geographic volume whose radii correspond to the limit of audibility for a specific signal. In other words, an active space provides an answer to the question, "how far can you hear a given sound at a specific place on Earth's surface?"
This repository is designed to estimate active spaces for fixed-wing aircraft noise within the U.S. National Park System. Aircraft are powerful noise sources audible over vast areas. Thus considerable NPS management efforts have focused on protecting natural quietude from aviation noise. NPS-ActiveSpace provides a quantitative tool to support managers in monitoring park resource condition.
Consider an example active space, below. It was computed using data from a long term acoustic monitoring site in Denali National Park, DENAUWBT Upper West Branch Toklat (Withers 2012). The bold black polygon delineates an active space estimate for flights at 3000 meters altitude. Points interior to the polygon are predicted to be audible, those exterior inaudible.
Superposed over the polygon are colored flight track polylines. NPS-ActiveSpace includes an application that leverages the acoustic record to ground-truth audibility of co-variate vehicle tracks from GPS databases. Ground-truthing is used to "tune" an active space to the appropriate geographic extent.
This project is made up of four packages:
utils: diverse utilities - file I/O, geoprocessing computations, acoustic propagation modelling, and detection statistics
ground-truthing: a tkinter-based ground-truthing application
active-space: generate and tune active space polygons
analysis: estimate acoustic metrics from the intersection of an active space polygon and vehicle tracks
Also included are noise source data for tuning active space polygons.
For more specific information on each package, view their individual READMEs.
While each package can be used and run individually, the project was designed so that outputs of one package work seamlessly as the inputs for another.
Packages were designed to be run in the following order:
ground-truthingactive-spaceanalysis
This project is in the worldwide public domain:
This project is in the public domain within the United States, and copyright and related rights in the work worldwide are waived through the CC0 1.0 Universal public domain dedication.
All contributions to this project will be released under the CC0 dedication. By submitting a pull request, you are agreeing to comply with this waiver of copyright interest.