Selection of Minimum Day/Night Levels for Noisemap Contour Calculations

Abstract

This report discusses guidelines for the minimum Day/Night Level (DNL) values that should be used with NOISEMAP type computations to: (1) insure adequate accuracy of the lowest contour level for a given set of aircraft operations; and (2) minimize the number of machine computations and thereby reduce operating costs. An analysis is made of the errors introduced in the DNL contour values due to truncation of the partial DNL cutoff determined by the single event noise level or the number of aircraft operations for a particular flight path. For a given airbase and fixed volume of aircraft operations, the cutoff occurs at higher single event noise levels as the number of aircraft flight paths or aircraft classes are increased. Finer detail in describing the aircraft operations results in the cutoff noise levels being raised with an increased error at the edges of the DNL grid computations, but with a corresponding decrease in the machine running time. These DNL cutoff guidelines have been incorporated into version 3.4 of NOISEMAP.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1976
Accession Number
ADA040623

Entities

People

  • Dwight E. Bishop

Organizations

  • BBN Technologies

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Acquisition
  • Air Force
  • Air Force Facilities
  • Aircraft Noise
  • Aircrafts
  • Biomedical Research
  • Civil Engineering
  • Communities
  • Computations
  • Computer Programs
  • Errors
  • Flight
  • Flight Paths
  • Noise
  • Procurement
  • Truncation

Readers

  • Acoustics.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Systems Analysis and Design

Technology Areas

  • Space