By interaction between ultrasonic waves and elastic medium, it has carried much information of material, which are received in the form of ultrasonic echo signals.
By interaction between ultrasonic waves and elastic medium, it carries much information of material, which is received in the form of ultrasonic echo signals.
The WDA (acronym of Wavelet, Detail and Approximate) cross-correlation method based on wavelet transform was developed in consideration of measuring ultrasound echo signals to reduce the effects of noise, template window sizes and flaws on the time delay estimate using cross-correlation methods.
Using the circuits, double ultrasound pulses could be made synchronously to satisfy the requirements of ultrasound thermometry, and the weak ultrasound echo signals are received successfully.
In the ultrasonic nondestructive test of pipeline,there is much defect information in the ultrasonic echo-signal of pulse reflection,but the echo-signal is disturbed by electronic noise,structure noise and so on. Before analyzed,the ultrasonic defect echo signal must be denoised to get better results.
Measurements were carried out under hydrostatic pressure up to 0.5GPa at room temperature,by using an ultrasonic pulse-echo method to measure the transit time of longitudinal and transverse elastic waves(10MHz)in a Nd_ 60Al_ 10Fe_ 20Co_ 10 bulk metallic glass.
This paper analysed the limitations of resolution of ultrasonic detection and presented a method of optical computing real-time processing for ultrasonic pulse-echo.
The possibility of using homomorphic filtration of ultrasonic echo signals, as a preliminary data processing method, for upgrading the flaw images obtained during coherent echo-signal processing is considered.
Experimental data determined via the ultrasonic echo-shock technique on the internal boundaries of wear in the fireproof lining and skull layer in the bottom part of a blast furnace are discussed.
Experimental data show that the auditory system of the harbor porpoise is tuned to detecting ultrasonic echo signals in the frequency range within 120-140 kHz.
In 8 conscious men it was studied how application of sub and above atmospheric pressure to the head and neck region influences the diameter of the intact common carotid artery, which was measured with an ultrasound echo-ranging device.
Ultrasound images are assembled by computer using the angle of the catheter tip and its linear advance associated with each ultrasound echo signal.In vivo experimental results are presented.