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| | Abstract | | We improve a method that derives a more accurate measurement of ultrasonic attenuation by using sweep-type signals. We obtained spectral amplitude of the sweep signal in frequency-time domain using the continuous wavelet transform and estimated attenuation in the time-frequency domain using the spectral-ratio method. The advantage of this method is independent on the effect of windowing. We used partially frozen brine as a solid-liquid coexistence system to investigate attenuation phenomena. Ultrasonic wave-transmission measurements on an ice-brine coexisting system were conducted to examine the influence of unfrozen brine in the pore microstructure on ultrasonic waves. We quantitatively estimated attenuation in a frequency range of 350-600 kHz by considering different distances between the source and receiver transducers. |
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