Examples of usage of nearfield acoustic holography methods for far field estimations: Part 1. CW signals

Abstract

The paper is devoted to the usage of nearfield acoustic holography methods for estimating far field of the object. An experiment was carried out in anechoic chamber. First, acoustic filed was recorded in a plane that was close to source. This signals records were used to reconstruct the far field by computation routines. Second, the signal in the far field is measured and the results are compared. Several methods are tested and research on possible reduction of the microphone array size is carried out. The most significant reduction of the measurement facility complexity is usage a linear array in stead of the planar array that is made possible due to introduced computation routines