Temporal coherence of a soundfield in the turbulent atmosphere near the ground

Marta Galindo Arranz, Dave I. Havelock

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

    Abstract

    A sound field propagating through the atmosphere changes with time due to the dynamics of the inhomogeneous medium. The coherence time, defined as the time lag beyond which the auto correlation is less than 1/e, is a time scale for dynamics of the medium as well as design criteria for coherent processing of received signals. Examples of coherence data are presented and their characteristic interpreted. The experimental data consist of continuous tone signals, between 400 Hz and 1000 Hz, received simultaneously over intervals of five minutes at ranges up to 700 m. The data are processed to estimate the temporal coherence for individual tones at various ranges. The source and the receivers were positioned near the ground. Both upward and downward refracting conditions are considered. The characteristics of the data observed during the different conditions are related to simple models of the corresponding propagation mechanisms. Good agreement is found between the theory and measurements.
    Original languageEnglish
    Title of host publicationSeventh International Symposium on Long Range Sound Propagation
    Place of PublicationEcully
    PublisherLaboratoire de Mécanique des Fluides et d'Acoustique, Ecole Centrale de Lyon
    Publication date1996
    Pages149-159
    Publication statusPublished - 1996
    Event7th International Symposium on Long Range Sound Propagation - Lyon, France
    Duration: 24 Jul 199626 Jul 1996
    Conference number: 7

    Conference

    Conference7th International Symposium on Long Range Sound Propagation
    Number7
    CountryFrance
    CityLyon
    Period24/07/199626/07/1996

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