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.

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.

Systems and methods for determining orientations measurements are provided. In one aspect, the method includes receiving a magnetic field state of an object, receiving a magnetic field measurement associated with the object, receiving an inertial measurement unit (IMU) measurement associated with the object, receiving a previous gravitational state term associated with the object, determining a gravitational acceleration state term based on the IMU measurement and the previous gravitational state term, determining a magnetic field state term based on the IMU measurement, the magnetic field measurement, and the gravitational acceleration term, and determining an orientation of the object using the gravitational acceleration state term and the magnetic field state term. The magnetic field measurement may be received from a magnetometer, and the IMU measurement may be received from a gyroscope and an accelerometer.

Systems and methods for determining orientations measurements are provided. In one aspect, the method includes receiving a magnetic field state of an object, receiving a magnetic field measurement associated with the object, receiving an inertial measurement unit (IMU) measurement associated with the object, receiving a previous gravitational state term associated with the object, determining a gravitational acceleration state term based on the IMU measurement and the previous gravitational state term, determining a magnetic field state term based on the IMU measurement, the magnetic field measurement, and the gravitational acceleration term, and determining an orientation of the object using the gravitational acceleration state term and the magnetic field state term. The magnetic field measurement may be received from a magnetometer, and the IMU measurement may be received from a gyroscope and an accelerometer.

An aerial-and-ground data combined gravity conversion method includes the following steps: calculate the first estimated ground gravity by the Runge-Kutta format 1, and calculate the first error between the first estimated ground gravity and the measured ground gravity; calculate the second estimated ground gravity by the Runge-Kutta format 2, and calculate the second error between the second estimated ground gravity and the measured ground gravity; and select the smaller one from the first and second errors, use the corresponding Runge-Kutta format as the Runge-Kutta format for gravity conversion, and finish the gravity data conversion using the mentioned Runge-Kutta format.

The present invention describes methods, systems, and devices for utilizing high-intensity regions within atmospheres of planetary bodies to receive and harvest electricity. Such high-intensity regions are formed as a result of the combined gravitational forces affecting a given planetary body and particularly the particles within the atmosphere of that planetary body. The combined gravitational forces result in a gravitational resonant frequency which affects the atmosphere most intensely within said high-intensity regions. By determining moments of gravitational resonant frequencies based on a given location, the methods, systems, and devices described herein utilize the energy provided within the high-intensity regions during the determined moments. Harvesting and further transmitting the collected energy is also disclosed.

The present invention describes methods, systems, and devices for utilizing high-intensity regions within atmospheres of planetary bodies to receive and harvest electricity. Such high-intensity regions are formed as a result of the combined gravitational forces affecting a given planetary body and particularly the particles within the atmosphere of that planetary body. The combined gravitational forces result in a gravitational resonant frequency which affects the atmosphere most intensely within said high-intensity regions. By determining moments of gravitational resonant frequencies based on a given location, the methods, systems, and devices described herein utilize the energy provided within the high-intensity regions during the determined moments. Harvesting and further transmitting the collected energy is also disclosed.

The present disclosure discloses a submarine position detection method based on extreme points of gravity gradients. A space rectangular coordinate system is established by taking a centroid of the middle cylindrical portion as a coordinate origin, a direction pointing to a bow is taken as a forward direction of the X axis, a direction pointing to a port is taken as a forward direction of the Y direction, and a vertical upward direction is taken as a forward direction of the Z axis. The detection method includes steps of: determining a horizontal position of a submarine, i.e., coordinates (X, Y), according to a position of a central extreme point and a central position between extreme points of non-diagonal components of a gradient tensor; and determining a functional relation between a depth and the extreme points of gravity gradients by using the submarine model.

The present disclosure discloses a submarine position detection method based on extreme points of gravity gradients. A space rectangular coordinate system is established by taking a centroid of the middle cylindrical portion as a coordinate origin, a direction pointing to a bow is taken as a forward direction of the X axis, a direction pointing to a port is taken as a forward direction of the Y direction, and a vertical upward direction is taken as a forward direction of the Z axis. The detection method includes steps of: determining a horizontal position of a submarine, i.e., coordinates (X, Y), according to a position of a central extreme point and a central position between extreme points of non-diagonal components of a gradient tensor; and determining a functional relation between a depth and the extreme points of gravity gradients by using the submarine model.

An atomic interferometer and methods for measuring phase shifts in interference fringes using the same. The atomic interferometer has a laser beam traversing an ensemble of atoms along a first path and an optical components train with at least one alignment-insensitive beam routing element configured to reflect the laser beam along a second path that is anti-parallel with respect to the first laser beam path. Any excursion from parallelism of the second beam path with respect to the first is rigorously independent of variation of the first laser beam path in yaw parallel to an underlying plane.