Real-time digital signal recovery for sensors and amplifiers with resonant characteristics

Abstract

A digital signal processing (DSP)-based real-time signal recovery method suitable for a real-valued processing core is presented with a goal of compensating for all the anomalies due to the resonant behaviors of a linear low pass system with complex poles, such as geophone sensors and piezoelectric acceleration sensors. The recovery method is DC-accurate and effectively flattens the frequency response curves up to an adjustable frequency limit of ∼O(0.1/Ts) (Ts is the sampling period of the DSP system) which can be well beyond the conventional cut-off or resonance frequencies of the system. The method can also filter out transient signals due to arbitrary initial conditions and strong resonance. A detailed method to enhance the signal-to-noise ratio is proposed and tested with a set of time-domain and frequency-domain analyses, demonstrating its effectiveness in various parameter conditions.