Various implementations disclosed herein include devices, systems, and methods for normal estimation using a directional measurement, such as a gravity vector. In various implementations, a device includes a non-transitory memory and one or more processors coupled with the non-transitory memory. In some implementations, a method includes identifying planar surfaces in an environment represented by an image. Each planar surface is associated with a respective orientation. A directional vector associated with the environment is determined. A subset of the planar surfaces that have a threshold orientation relative to the directional vector is identified. For each planar surface in the subset of the planar surfaces, a normal vector for the planar surface is determined based on the orientation of the planar surface and the directional vector.

A method and a system are disclosed for maintaining accuracy of a photogrammetry system comprising a stereo pair of cameras and characterized by calibration parameters determined at initialization, the system for tracking one of a touch probe and a 3D sensor, the method comprising in use, continuously detecting a presence of a reduced number of 3D target points comprising at least one pair of 3D target points selected in a group comprising at least two 3D target points; measuring image position data associated with the at least one pair of 3D target points of the reduced number of 3D target points; computing at least one updated calibration parameter using the measured image position data and corresponding reference distance data associated with the at least one pair of 3D target points of the reduced number of 3D target points; and updating at least one calibration parameter of the photogrammetry system.

A method and a system are disclosed for maintaining accuracy of a photogrammetry system comprising a stereo pair of cameras and characterized by calibration parameters determined at initialization, the system for tracking one of a touch probe and a 3D sensor, the method comprising in use, continuously detecting a presence of a reduced number of 3D target points comprising at least one pair of 3D target points selected in a group comprising at least two 3D target points; measuring image position data associated with the at least one pair of 3D target points of the reduced number of 3D target points; computing at least one updated calibration parameter using the measured image position data and corresponding reference distance data associated with the at least one pair of 3D target points of the reduced number of 3D target points; and updating at least one calibration parameter of the photogrammetry system.

A method and apparatus for for sensing a change in an acceleration gradient δa(t) between two gravity fields a.sub.1(t) and a.sub.2(t) respectively sensed by the first and second proof masses, the first and second proof masses either being coupled only to a first resonator or being individually coupled to first and second resonators, the first resonator generating, in use, a signal at a frequency f.sub.D which is applied said second resonator, the second resonator being driven, in use, into a non-linear state corresponding to a modal resonant frequency f.sub.Θ wherein it generates a comb of frequencies each tooth of which is separated from each other by a frequency Δ which is frequency-wise proportional a frequency difference between f.sub.D and f.sub.Θ and also proportional to the change in said acceleration gradient δa(t), circuitry for selecting an n.sup.th tooth in said comb of frequencies where the frequency of the n.sup.th tooth is equal to f.sub.D+nΔ, circuitry for detecting a change in the frequency of the n.sup.th tooth and for generating a signal that is proportional to n times the change in an acceleration gradient δa(t).

A photonically multiplexed optical measurement apparatus for performing optical multiplexing includes a laser that produces laser light, an optical switch that receives the laser light from the laser and produces a switched laser light, and a plurality of sensor heads, each sensor head being configured to measure a respective physical property of a plurality of cold atoms disposed in the sensor head. The optical switch optically switches the laser light from the laser to a selected sensor head and subsequently to a different sensor head.

The present invention may be used for forecasting various weather phenomena including but not limited to flyby anomalies, cyclones, tornadoes, killer (rogue) waves, earthquakes, lightning, sprites, and temperature fluctuations. The invention is based on knowledge of physical and mathematical models regarding the occurrence of Kukharev regions (i.e., K regions) resulting from gravitational resonances occurring within the Earth-Moon-Sun system (and similar systems located elsewhere). These gravitational resonances and combinations thereof, among other things, cause jumps in atmospheric pressure. Such jumps can be recorded and extrapolated to predict the locations and times of the occurrence of Kukharev regions and, in turn, the associated weather-related effects.

Disclosed are method and apparatus for obtaining residual gravity anomaly. The method comprises obtaining Bouguer gravity anomaly of a target region, determining a first pre-set range corresponding to each sampling point in the target region, obtaining a first regional field value of each sampling point in the first pre-set range through a surface fitting method based on the coordinate and field value of the sampling point, traversing the target region to obtain first regional gravity anomaly of the target region according to the first regional field values of the sampling points in the target region, and obtaining first residual gravity anomaly of the target region according to the Bouguer gravity anomaly and the first regional gravity anomaly. The residual gravity anomaly thus obtained is more accurate, thus enabling an accurate prediction of an underground geological body.

Disclosed are method and apparatus for obtaining residual gravity anomaly. The method comprises obtaining Bouguer gravity anomaly of a target region, determining a first pre-set range corresponding to each sampling point in the target region, obtaining a first regional field value of each sampling point in the first pre-set range through a surface fitting method based on the coordinate and field value of the sampling point, traversing the target region to obtain first regional gravity anomaly of the target region according to the first regional field values of the sampling points in the target region, and obtaining first residual gravity anomaly of the target region according to the Bouguer gravity anomaly and the first regional gravity anomaly. The residual gravity anomaly thus obtained is more accurate, thus enabling an accurate prediction of an underground geological body.

Various implementations disclosed herein include devices, systems, and methods for pose estimation using one point correspondence, one line correspondence, and a directional measurement. In various implementations, a device includes a non-transitory memory and one or more processors coupled with the non-transitory memory. In some implementations, a method includes obtaining an image corresponding to a physical environment. A first correspondence between a first set of pixels in the image and a spatial point in the physical environment is determined. A second correspondence between a second set of pixels in the image and a spatial line in the physical environment is determined. Pose information is generated as a function of the first correspondence, the second correspondence, and a directional measurement.

Various implementations disclosed herein include devices, systems, and methods for pose estimation using one point correspondence, one line correspondence, and a directional measurement. In various implementations, a device includes a non-transitory memory and one or more processors coupled with the non-transitory memory. In some implementations, a method includes obtaining an image corresponding to a physical environment. A first correspondence between a first set of pixels in the image and a spatial point in the physical environment is determined. A second correspondence between a second set of pixels in the image and a spatial line in the physical environment is determined. Pose information is generated as a function of the first correspondence, the second correspondence, and a directional measurement.