This Standard describes procedures for obtaining the acoustic impedance of ground surfaces from in-situ measurements of the magnitudes and relative phase of the sound pressures at two vertically separated microphones using specified geometries. It extends and revises the template method published as ANSI S1.18-1999 to enable the user to obtain impedance spectra that result entirely from measurements and are independent of any model for the acoustic impedance of the ground.
ANSI/ASA S1.18-2010 history
2010ANSI/ASA S1.18-2010 Method for Determining the Acoustic Impedance of Ground Surfaces