文档介绍：PREFACE
athematical modelling of the boundary-value problems associ•
ated with the scattering of acoustic or ic waves by
M bounded obstacles has been a subject of great interest during
the last few decades. This is primarily due to the fact that particle scatter•
ing analysis is encountered in many practical applications as, for example,
aerosol analysis, investigation of air pollution, radiowave propagation in the
presence of atmospheric hydrometers, weather radar problems, analysis of
contaminating particles on the surface of silicon wafers, remote sensing,
etc. Many techniques have been developed for analyzing scattering prob•
lems. Each of the available methods generally has a range of applicability
that is determined by the size of the scattering object relative to the wave•
length of the incident radiation. Scattering by objects that are very small
compared to the wavelength can be analyzed by the Rayleigh approxima•
tion, and geometrical optics methods can be employed for objects that are
electrically large. Objects whose size is in the order of the wavelength of
the incident radiation lie in a monly called the resonance region,
and plete wave nature of the incident radiation must be considered
in the solution of the scattering problem. Classical methods of solution
in the resonance region such as the finite-difference method, finite-element
method or integral equation method, owing to their universality, lead to
computational algorithms that are expensive puter resources. This
significantly restricts their use in studying multiparametric boundary-value
IX
X PREFACE
problems, and in particular in analyzing inverse problems which are mul-
tiparametric by nature. In the last few years, the discrete sources method
and the null-field method have e efficient and powerful tools for solv•
ing boundary-value problems in scattering theory.
The physical idea of the discrete sources method is linked with Huy-
gens'