Abstract: A wearable computing device such as a head-mounted display (HMD) may be equipped with a magnetometer for detecting presence and motion of a hand-wearable magnet (HWM). The HMD may analyze magnetic field measurements of the magnetometer to determine when the HWM moves within a threshold distance of the magnetometer, and may thereafter determine one or more patterns of motion of the HWM based the magnetic field measurements. The HMD may operate in a background detection state in order to determine a background magnetic field strength and to monitor for magnetic disturbances from the HWM. Upon occurrence of a trigger event corresponding to magnetic disturbance above a threshold level, the HMD may transition to operating in a gesture detection state in which it analyzes magnetometer measurements for correspondence with known gestures. Upon recognizing a known gesture, the HMD may carry out one or more actions based on the recognized known gesture.

Abstract: A vibrator-coupled ground filter improves seismic data recorded during a seismic operation. This filter is based on a ground model that takes into consideration the vibrator system, the coupling system between the baseplate and captured ground, and the coupled ground system. Using acceleration data from the baseplate and the reaction mass, the ground model can be used to derive particular variables for the ground model to help characterize the system. Using the derived variables in a ground filter, the recorded seismic data can be corrected to remove errors in the trace data produced by typical assumptions.

Abstract: A waveform generator and a signal analyzer are respectively provided in electrical communication with an input transducer and an output transducer capable of conversion between electrical and acoustic signals, and in mechanical communication with a part. A processor coupled with the waveform generator and signal analyzer receives a set of parameters defining a frequency scan from which it determines a number of frequency sweeps to be performed by the waveform generator. Each of the frequency sweeps has a number of frequencies less than a maximum capacity of the waveform generator, and for each frequency sweep, the processor instructs the waveform generator to excite the input transducer and synchronously receiving a response signal with the signal analyzer at multiple frequencies.