An ultrasonic imaging method is provided. A wideband acoustic pulse is fired at a wall. A wideband response signal is received. The wideband response signal is processed to select an impedance measurement frequency. A wavelet having a characteristic frequency approximately equal to the impedance measurement frequency is fired. A wavelet response signal is received. A reflection coefficient is determined from the wavelet response signal. An impedance measurement is calculated from the reflection coefficient. Related tools and systems are also disclosed.