Abstract: A method for correcting for distortions in a seismic acoustic wavefield produced by a seismic vibrator that is immersed in a fluid, the method comprising: applying a pilot signal to the vibrator such that an acoustic wavefield travels outwards from the interface between the vibrator outer surface and the fluid: using a sensor located within the fluid so as to be sensitive to a property of the wavefield in the fluid to monitor the property of the wavefield as a function of time: and using the measured property to determine a change in wet volume of a component of the vibrator as a function of time V(t) or derivatives of V(t), and using the determined wet volume V(t) or its derivatives to correct for distortions in the seismic data produced by the vibrator.

Abstract: A power meter for measuring power parameters on one or more electrical power lines/loads is configured to include a revenue class metering module and a power quality metering module. The revenue class metering module and the power quality metering module may use the same measured voltage and current signals to generate revenue accurate power consumption information and power quality information, respectively. The power meter may also include a plurality of filters configured to attenuate high frequency signals included in the voltage and current signals. Each of the filters may be configured with a corner frequency, gain and signal propagation delay that is substantially equal. The filtered current and voltage signals may be received and processed by the revenue class metering module, and the power quality metering module to generate revenue accurate power consumption information and power quality information, respectively.