Inverse Distance Weighting for Extrapolating Balloon-Directivity-Plots
Joerg Panzer and Daniele Ponteggia from Audiomatica presented this paper to the AES 131th Convention in New York, and, so, for the serious-minded students of acoustics, we have asked him and the AES for permission to reproduce it here.
This paper investigates an extrapolation for missing directivity-data in connection with Balloon-Plots. Such plots display the spherical directivity-pattern of radiators and receivers in form of contoured sound pressure levels. Normally the directivity-data are distributed evenly so that at each point of the display-sphere there would be sufficient data-points. However, there are circumstances where we want to display data that are not evenly distributed. For example, there might be only available the horizontal and vertical scans. The proposed Inverse Distance Weighting method is a means to extrapolate into these gaps. This paper explains this method and demonstrates some examples.
Please click here to see the pdf of Joerg's paper.