A ground wave image decoding section extracts a ground wave image signal from a ground wave broadcast signal received by a ground wave 2 tuner.
The voltage of V2 could keep constant or be different with time, such as a part of sine wave, square wave, a part of triangle wave, or a part of trpezoidal wave.
The method also includes receiving a second reflected wave (12b) at the second point, wherein the second reflected wave comprises a reflection of a shear wave generated as a result of the first pressure wave striking the floor.
The plurality of ultrasonic waves includes a first ultrasonic wave and a second ultrasonic wave, wherein the first ultrasonic wave and the second ultrasonic wave are formed out of phase.
The second split lightwave is delayed relative to the first split lightwave, to provide a delayed second split lightwave.
The acoustic wave may be an ultrasonic wave, and preferably has a polarized wave.
Preferably, the acoustic energy includes an acoustic wave and more preferably is at least one supersonic acoustic wave.
A microwave generator generates a microwave having a frequency wit hin a predetermined range.
The first acoustic wave may be a one-dimensional edge wave.
The surface elastic wave element (23) in contact with the vessel generates a sound wave.
The signal may be in the form of an electromagnetic wave, e.g. a microwave.