A hierarchical early-warning system for landslide probability issues a first level warning based on measured rainfall amounts exceeding a determined threshold, a second level warning, after the first level warning, based additionally on measured soil moisture content measured at different levels, and Factor of safety derived from forecasted pore pressure (FPP) each exceeding a determined threshold, a third level warning, after the first and the second level warnings, based additionally on ground movement measurements compared to a determined threshold, and a fourth level warning after the first, second and third level warnings, based additionally on data from movement-based sensors including strain gauge data.

A measurement device intended to be immersed in water, includes a set of arms and a reference axis, the measurement device being able to be in a deployed configuration, the measurement device comprising a set of measurement units borne by arms of the set of arms and each comprising an acoustic-waves sensor, the set of measurement units being configured and arranged in such a way as to generate a torque on the measurement device about the reference axis upon a vertical translational movement of the measurement device in the deployed configuration, the measurement device comprising compensation means configured and arranged in such a way as to generate another torque on the measurement device about the reference axis during the vertical translational movement, the other torque being directed in the opposite direction to the torque and having an intensity less than twice that of the torque.

A terrestrial acoustic sensor array for detecting and preventing airspace collision with an unmanned aerial vehicle (UAV) includes a plurality of ground-based acoustic sensor installations, each of the acoustic sensor installations including a sub-array of microphones. The terrestrial acoustic sensor array may further include a processor for detecting an aircraft based on sensor data collected from the microphones of at least one of the plurality of acoustic sensor installations and a network link for transmitting a signal based on the detection of the aircraft to a control system of the UAV.

A method, a system, and a device for full-waveform inversion deghosting for a marine variable depth streamer data acquisition are provided for solving existing problems that deghosted seismic data has low accuracy and is accompanied by artifacts due to a large error in ghost prediction. The provided method includes: acquiring seismic data, jointly solving Lippmann-Schwinger equations to obtain normal derivatives of an incident wave field and a wave field of a receiver surface, performing a wave field extrapolation by a Kirchhoff equation that includes only an integral on the receiver surface to obtain a wave field of a sea surface recorded by a horizontal streamer, calculating a ghost operator, and subjecting the ghosted wave field of the sea surface recorded by the horizontal streamer to full-waveform inversion deghosting to obtain deghosted seismic data. The provided method improves the accuracy and signal-to-noise ratio (SNR) of deghosted seismic data.

A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

In some implementations, a system may receive a cable map for a deployed cable. The system may receive vibration data indicating a vibration associated with a first section of the cable. The system may determine a characteristic associated with the first section of the cable based on the vibration. The system may determine a location associated with the characteristic based on the cable map. The system may determine that the first section of the cable is associated with the location based on the location being associated with the characteristic. The system may associate the location and a length of a second section of the cable extending from an initial location to the location. The system may receive an input identifying the length of the second section of the cable and may output the location based on associating the location and the length of the second section of the cable.

In some implementations, a system may receive a cable map for a deployed cable. The system may receive vibration data indicating a vibration associated with a first section of the cable. The system may determine a characteristic associated with the first section of the cable based on the vibration. The system may determine a location associated with the characteristic based on the cable map. The system may determine that the first section of the cable is associated with the location based on the location being associated with the characteristic. The system may associate the location and a length of a second section of the cable extending from an initial location to the location. The system may receive an input identifying the length of the second section of the cable and may output the location based on associating the location and the length of the second section of the cable.

A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

An apparatus comprises a distributed acoustic sensing (DAS) optical fiber, a DAS interrogator coupled to the DAS optical fiber, and a connector. The connector couples the DAS interrogator, a first digitizer, and a second digitizer, wherein the first digitizer is to generate a first digitized DAS signal based on an analog DAS signal from the DAS interrogator, and the second digitizer is to generate a second digitized DAS signal based on the analog DAS signal. The apparatus also comprises one or more processors and a machine-readable medium having program code executable to cause the apparatus to simultaneously generate a first set of values that correlate with a first physical property based on the first digitized DAS signal and generating a second set of values that correlate with a second physical property based on the second digitized DAS signal.

An apparatus comprises a distributed acoustic sensing (DAS) optical fiber, a DAS interrogator coupled to the DAS optical fiber, and a connector. The connector couples the DAS interrogator, a first digitizer, and a second digitizer, wherein the first digitizer is to generate a first digitized DAS signal based on an analog DAS signal from the DAS interrogator, and the second digitizer is to generate a second digitized DAS signal based on the analog DAS signal. The apparatus also comprises one or more processors and a machine-readable medium having program code executable to cause the apparatus to simultaneously generate a first set of values that correlate with a first physical property based on the first digitized DAS signal and generating a second set of values that correlate with a second physical property based on the second digitized DAS signal.