scattering differential
5.51 scattering differential. Amount by which the level of the scattered time-mean-square sound pressure averaged over all directions at a specified unit distance from the effective acoustic center of the scattering object exceeds the plane-wave free-field pressure level of the sound incident upon the object. The scattering differential of an object is 10 times the logarithm to the base 10 of the ratio of the scattering cross section to the surface area of the sphere of unit radius surrounding the object.
backscattering cross section
5.50 backscattering cross section. Of an object, 4 π steradians multiplied by the differential scattering cross section of that object, evaluated back in the direction from which the sound originates. Unit, meter squared (m2).
scattering cross section (of an object or volume)
5.49 scattering cross section (of an object or volume).The differential scattering cross section of the object or volume, integrated over all solid angles. Unit, meter squared (m2); Symbol σ
differential scattering cross section
5.48 differential scattering cross section. Ratio of the free-field scattered sound power per unit solid angle in a specified direction to the intensity of the incident propagating plane sound wave. Unit, meter squared per steradian (m2/sr) Symbol, Sd.
acoustic scattering
5.47 acoustic scattering. Irregular reflection, refraction, or diffraction of sound in many directions.