Historical
ANSI S1.18-1999 (R2004)
Template Method for Ground Impedance
Describes procedures for obtaining the real and imaginary parts of the specific acoustic impedance of natural ground surfaces outdoors. The Standard uses templates to compare measured sound pressure level differences with a specific set of calculated level differences. The impedance values are obtained from a model based on best fit of measured and calculated level differences. The standard may also be used to obtain the impedance of porous sound absorbing material.
Acoustical Society of America [asa]
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