Accession Number : AD0682551

Title :   SCATTERING OF LINEAR FM ACOUSTIC PULSES FROM ALUMINUM SPHERES IN WATER.

Descriptive Note : Technical memo.,

Corporate Author : TEXAS UNIV AUSTIN DEFENSE RESEARCH LAB

Personal Author(s) : Mikeska,E. E.

Report Date : 20 NOV 1968

Pagination or Media Count : 39

Abstract : Experimentally recorded farfield echoes from linear frequency modulated pulses incident on precision aluminum spheres in water are compared with computed echo forms. Good agreement was found using different pulse lengths and swept bandwidths. Spheres having ratios of internal to external radius of 0.95, 0.8, and 0.0 were studied, with either air or water in the hollow interior. Multiple periodic secondary echo components observed under some pulse conditions are interpreted in terms of circumferential waves and internal reflections. Crosscorrelations of incident pulses with corresponding echoes aid in the analysis of echo structure. (Author)

Descriptors :   (*UNDERWATER SOUND, SCATTERING), SPHERES, ALUMINUM, FREQUENCY MODULATION, PULSES, CORRELATION TECHNIQUES, REFLECTION

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE