Nearfield Radiated Noise Study

摘要

The study consists of three related parts. Each part deals with some aspect of radiated noise measurement in which the measurement can be in the near field of the source or the combination of the source and its surface image. In the first part the estimation of far field pressure waveform is examined to determine the dependence of the estimator upon the nature of the source. In the second the effect of surface image interference upon the estimate of radiated noise intensity mean and variance is investigated. In the third part the dependence of the spectrum measurement upon the position in the field of the source is shown to be significant. (Author)