"(Rivers." . . "High frequency." . . "Underwater objects." . . "Acoustics." . . "Absorption." . . "Sonar equipment." . . "Colloids." . . "Hydrology, Limnology and Potamology." . . "Texas)" . . . . "Detection." . . "Mud." . . "Scattering." . . . . . . . "The use of high frequency sonar techniques for detection and study of submerged objects and geological features in rivers can be limited by the acoustic attenuation. This parameter was measured in a pilot study of the lower reaches of the Brazos River near Houston, Texas. The attenuation was due to the suspended particulate matter carried by this muddy river. At a frequency of 200 kHz and for a particulate concentration of 0.025% by weight with a mean particulate radius of 1.5 microns, the attenuation was found to be 1.5 dB/100 yd. This work was supported by the Office of Naval Research. (Author)."@en . . . "A geoacoustic survey of the brazos river. part ii. ultrasonic attenuation studies"@en . . . . . . . . . . . . . . . . . . . . . . "Measurement." . . "Echo ranging." . . "(Underwater sound." . . "Attenuation)" . . "Ultrasonic properties." . . "Electronic equipment." . . "TEXAS UNIV AT AUSTIN DEFENSE RESEARCH LAB." . . "Acoustic Detection and Detectors." . . "Anomalies." . . "Particles." . .