Accession Number : AD0696957

Title :   ON THE UPPER AND LOWER LIMITS TO THE RYTOV APPROXIMATION,

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : Modesitt,G. E.

Report Date : SEP 1969

Pagination or Media Count : 25

Abstract : The equation for wave propagation in a random medium cannot be solved analytically; in order to estimate theoretically the amplitude and phase fluctuations of the wave, certain standard approximations--linearization of the wave equation, forward scattering assumption--have been widely adopted. The consequent restrictions on the validity of the solutions is estimated and presented in the form of lower and upper range limits. Various upper limits, the consequence of the linear approximation, have previously been obtained by other methods. These approaches are discussed and their discrepancies explained; the lower limit and the general consequences of the forward scattering assumption have not previously been noted. In particular, it is shown that, for optical propagation in the atmosphere, the lower and upper limits coincide and that the standard approximations are consequently invalid. (Author)

Descriptors :   (*ATMOSPHERES, LIGHT TRANSMISSION), (*APPROXIMATION(MATHEMATICS), ACCURACY), DIFFRACTION, ATMOSPHERIC MOTION, REFRACTIVE INDEX, PARTIAL DIFFERENTIAL EQUATIONS, OPTICAL COMMUNICATIONS, COHERENT RADIATION

Subject Categories : Numerical Mathematics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE