Parametric Approach on Field Propagation
Conventional Fourier transform method of angular spectrum propagation to estimate field distribution at planes distant from the measuring plane has several problems. These are wrap-around arror, replicated sources problem and side-lobe leakage effects due to windowing the data. These effects are inevitable as far as the discrete Fourier transform is concerned. One suggestion to eliminate these effects is to apply a parametric modelling approach to estimate the Fourier transform pair.
We have found that the auto-regressive (AR) modelling approach has better resolution than the Fourier transform method when used to estimate source field distributions. The modelling method produces even better results when it is applied to the new Fresnel integral to get a direct spatial source property distribution, rather than using the angular spectrum propagation approach.
KeywordsDiscrete Fourier Transform Angular Spectrum Frequency Domain Approach Small Angle Approximation Fresnel Approximation
Unable to display preview. Download preview PDF.
- J.P. Powers, “computer simulation of linear acoustic diffraction,” in Acoustic Holograph, edited by A. Metherell (Plenum, New York, 1974), vol. 7, pp. 193–205.Google Scholar
- J.W. Goodman, “Introduction to Fourier optics,” Ch. 3 and Ch. 4., Mcgraw-Hill, New York, 1968.Google Scholar
- W.J. Graham, “A new Fresnel region approximation,” Proc, Int. IEEE AP-S Symposium, Vancouver, BC. Jun. 1985.Google Scholar