Backscattering programs for spherical targets
Abstract
These programs compute the acoustical reflectivity of a sphere in a fluid medium. The programs differ in the allowed physical properties of the spheres. The principal outputs of the programs are plots of reflectivity, Rsquared, as a function of sizefrequency, ka. The reflectivity is defined as Rsquared = (sigma sub b)/(asquared/4) where sigma sub b is the backscattering crosssection of the sphere, and asquared/4 is the backscattering crosssection of a completely reflecting sphere of radius a. The variable k is the wavenumber in the medium. These plots may be considered as dimensionless representations of target strength vs. frequency. The conversions are TS = 10 log (Rsquared times asquared/4) and f = cKa/2pia with a in meters, c in meters per second and f in kHz. This relation for frequency is such that the product of frequency in kHz and radius in mm is 240 when ka = 1. These programs have been used primarily for low contrast cases (with g and h near one) at relatively low values of ka (less than 10).
 Publication:

Unknown
 Pub Date:
 April 1979
 Bibcode:
 1979bpst.book.....J
 Keywords:

 Backscattering;
 Computer Programs;
 Radar Targets;
 Acoustic Scattering;
 Reflectance;
 Scattering Cross Sections;
 Spheres;
 Acoustics