Spatial transformation of sound fields

In this paper it will be demonstrated how cross spectra measured by a modified 1/3 octave realtime intensity analyzer during a planar scan can be used to predict pressure, particle velocity, and intensity in a half‐space not containing the source of the (noise) field. We just have to assume a rather limited number of significant uncorrelated components in the total source. In the nearfield region on both sides of the scan plane the field quantities are evaluated using a nearfield holography technique similar to the technique described by Williams, Maynard, and Skudrzyk [J. Acoust. Soc. Am. 68, 340–344 (1980)] for analysis of coherent sound fields. Outside the nearfield region Helmholtz' integral equation is used for the prediction. The combined method allows various simulations to be carried through. For example we can estimate a planar source distribution by means of the holography method, simulate an attenuation of some part of the source, and investigate the effect of this attenuation on the field in t...