An adaptive technique for isolating the seismic response of an infrasound sensor

This paper presents the adaptive noise cancellation model as a method for isolating the seismic response of an infrasound sensor. While this response has been thoroughly characterized in the laboratory, to date there has not been an effective method for isolating it in the field. The technique developed in this paper utilizes a collocated seismometer as a reference signal and then applies an adaptive filter to isolate the infrasound sensor´s seismic response. In this paper, two adaptive algorithms are investigated for both cost and performance, including Least Mean Squares (LMS) and Block LMS (BLMS). The technique is applied to a real-world data set obtained from the October 2011 Turkish earthquake, and the results demonstrate its effectiveness in isolating the seismic response. The technique developed in this paper provides access to two previously unattainable signals: the isolated seismic response and the infrasound response uncorrupted by seismic noise. Once separated, these signals open the doors to many new and exciting applications, including augmentation of co-located seismic measurements, more precise calibration of fielded infrasound sensors, and a lowered noise floor for better detection of infrasonic events.