Gravity surveys of subterranean formations may be based on the simultaneous measurement of gravity and its derivatives to produce a higher resolution formation map or wellbore log. For example, a method of performing a gravity survey may include positioning a matter wave interferometer relative to a subterranean formation; producing at least one cloud of atoms in the matter wave interferometer; producing a superposition of atoms in two different, spatially separated superimposed clouds from each of the at least one cloud of atoms; propagating the two different, spatially separated superimposed clouds along the matter wave interferometer as they with a gravitational field of the subterranean formation; combining the two different, spatially separated superimposed clouds with a Raman laser beam; measuring an interference produced by producing and combining the two different, spatially separated superimposed clouds; and calculating gravity for the gravitational field of the subterranean formation based on the interference.

Provided is a gravity gradient measurement apparatus and measuring method, wherein a turntable rotates horizontally around an earth-vertical axis, a vacuum layer is arranged on the turntable defining a first chamber, a first three-axis accelerometer and a second three-axis accelerometer are located in the first chamber, the first three-axis accelerometer and the second three-axis accelerometer are arranged symmetrically on an x axis with respect to an origin of coordinates. Both the first three-axis accelerometer and the second three-axis accelerometer have a distance of R from the origin of coordinates. The first three-axis accelerometer and the second three-axis accelerometer are arranged symmetrically on an z axis with respect to the origin of coordinates, and the first three-axis accelerometer and the second three-axis accelerometer are spaced at a distance of h on the z axis. The measurement module uses measurements of the accelerometers to determine gravity gradients on the coordinate axes.

Provided is a gravity gradient measurement apparatus and measuring method, wherein a turntable rotates horizontally around an earth-vertical axis, a vacuum layer is arranged on the turntable defining a first chamber, a first three-axis accelerometer and a second three-axis accelerometer are located in the first chamber, the first three-axis accelerometer and the second three-axis accelerometer are arranged symmetrically on an x axis with respect to an origin of coordinates. Both the first three-axis accelerometer and the second three-axis accelerometer have a distance of R from the origin of coordinates. The first three-axis accelerometer and the second three-axis accelerometer are arranged symmetrically on an z axis with respect to the origin of coordinates, and the first three-axis accelerometer and the second three-axis accelerometer are spaced at a distance of h on the z axis. The measurement module uses measurements of the accelerometers to determine gravity gradients on the coordinate axes.

A method and a device for determining a device placement to optimize techniques, such as power management techniques, are described. The method, executed in a processor of a mobile device, comprises gathering data from at least one sensor associated with the mobile device. Based on the data gathered from the sensor, a device placement indicative of at least one of an orientation and a position the mobile device may be determined. Further, details pertaining to the device placement may be integrated with secondary classification data comprising at least one of historical data, device orientation data, and device motion data. Based on the integrated details, it may be inferred whether a user is engaged with the mobile device. When a user is not engaged with the mobile device, a brightness of the display is lowered in at least one stage to optimize power consumption and user experience.

A method and a device for determining a device placement to optimize techniques, such as power management techniques, are described. The method, executed in a processor of a mobile device, comprises gathering data from at least one sensor associated with the mobile device. Based on the data gathered from the sensor, a device placement indicative of at least one of an orientation and a position the mobile device may be determined. Further, details pertaining to the device placement may be integrated with secondary classification data comprising at least one of historical data, device orientation data, and device motion data. Based on the integrated details, it may be inferred whether a user is engaged with the mobile device. When a user is not engaged with the mobile device, a brightness of the display is lowered in at least one stage to optimize power consumption and user experience.

A method and a device for determining a device placement to optimize techniques, such as power management techniques, are described. The method, executed in a processor of a mobile device, comprises gathering data from at least one sensor associated with the mobile device. Based on the data gathered from the sensor, a device placement indicative of at least one of an orientation and a position the mobile device may be determined. Further, details pertaining to the device placement may be integrated with secondary classification data comprising at least one of historical data, device orientation data, and device motion data. Based on the integrated details, it may be inferred whether a user is engaged with the mobile device. When a user is not engaged with the mobile device, a brightness of the display is lowered in at least one stage to optimize power consumption and user experience.

A method and a device for determining a device placement to optimize techniques, such as power management techniques, are described. The method, executed in a processor of a mobile device, comprises gathering data from at least one sensor associated with the mobile device. Based on the data gathered from the sensor, a device placement indicative of at least one of an orientation and a position the mobile device may be determined. Further, details pertaining to the device placement may be integrated with secondary classification data comprising at least one of historical data, device orientation data, and device motion data. Based on the integrated details, it may be inferred whether a user is engaged with the mobile device. When a user is not engaged with the mobile device, a brightness of the display is lowered in at least one stage to optimize power consumption and user experience.

A time-delayed enlarged three-dimensional (3D) gravitational wave detection system may include a three optical fibers along three axes (X, Y, and Z-axis); and a laser signal source operatively linked with the three optical fibers; wherein structures of the three optical fibers are identical, and are adapted to pick up space/lengths changed caused by gravitational waves. And, the laser signal source includes a narrow linewidth laser to generate laser lights, an electro-optic modulator (EOM) connected with the narrow linewidth laser to modulate the phase of laser light, and a RF signal source connected to the EOM to provide ultra-stable RF signal to the EOM. In one embodiment, said narrow linewidth laser is adapted for carrying the ultra-stable RF signal, and said ultra-stable RF source is used for detecting length changes caused by the gravitational waves.

A time-delayed enlarged three-dimensional (3D) gravitational wave detection system may include a three optical fibers along three axes (X, Y, and Z-axis); and a laser signal source operatively linked with the three optical fibers; wherein structures of the three optical fibers are identical, and are adapted to pick up space/lengths changed caused by gravitational waves. And, the laser signal source includes a narrow linewidth laser to generate laser lights, an electro-optic modulator (EOM) connected with the narrow linewidth laser to modulate the phase of laser light, and a RF signal source connected to the EOM to provide ultra-stable RF signal to the EOM. In one embodiment, said narrow linewidth laser is adapted for carrying the ultra-stable RF signal, and said ultra-stable RF source is used for detecting length changes caused by the gravitational waves.

An apparatus for generating vertically separated atom clouds. The apparatus comprises an optical system comprising an arrangement of lenses and optics. The optical system is configured to trap and cool atoms to form a cold atom cloud; select the hyperfine level of the atoms; trap atoms of the cold atom cloud in a standing wave optical lattice; and vertically split the cold atom cloud into a high cold atom cloud and a low cold atom cloud. The splitting comprises splitting the cold atom cloud into two clouds by launching atoms of the cold atom cloud in opposite directions to form a high cold atom cloud and a low cold atom cloud, and catching the low cold atom cloud up to reach the same velocity as the high cold atom cloud.