20 results about "Gravitational potential" patented technology

The invention relates to a sea surface gravitational potential measuring method and device based on a satellite time-frequency strategy, and the method comprises the steps: placing two measuring systems at a land measuring station at the same time, carrying out the calibration and adjustment of clocks, and determining the system error between the clocks through zero baseline comparison; the mobile measurement system is placed on a ship and advances according to a designed experiment route, the measurement system can continuously operate, and position information and gravity potential information on an air route can be measured by combining a positioning system; the ship can sail according to any route, and the gravitational potential difference of any position on the sea surface can be measured with the help of a satellite; after the ship returns, the mobile measurement system and the fixed measurement system need to be compared again, and it is ensured that no large error occurs in the experiment process of the atomic clock. Therefore, the problems that gravitational potential data in the global range cannot be comprehensively obtained in real time, and on-sea gravitational potential measurement and cross-sea measurement are difficult to achieve are solved.

This invention discloses a virtual splicing and assembly method for satellite antennas based on the cooperative optimization of gravitational potential energy functions. The method includes: constructing a virtual assembly initialization scenario driven by multi-source data; constructing a global gravitational potential energy field based on theoretical surfaces, converting the geometric surface errors of the sub-lobes into global potential energy values; constructing a local cooperative constraint potential energy field based on boundary topological relationships, which includes an elastic tensile potential energy component characterizing the gap width and a torsional potential energy component characterizing the step difference and normal deflection; treating the sub-lobes to be assembled as rigid bodies, solving for the differential of pose parameters based on the total potential energy function, and obtaining the virtual net external force and virtual net torque acting on the centroid of the sub-lobes; based on the virtual net external force and virtual net torque, synchronously updating the spatial position and attitude angle of all sub-lobes along the opposite direction of the potential energy gradient, and recalculating the global gravitational potential energy function and the local cooperative constraint potential energy function until the total potential energy converges. This invention achieves efficient and accurate virtual splicing and assembly of satellite antennas.

This application relates to a satellite orbit prediction method. The method includes: constructing an expression for the gravitational force acting on the satellite based on its mass and distance from Earth; constructing a differential equation for the satellite's acceleration based on Newton's second law and the expression for the gravitational force; solving the differential equation based on the conservative force field characteristics of mechanics, calculating the gravitational potential energy function and its derivative with respect to time; transforming the derivative expression based on the mechanical conservation law that the sum of the derivatives of kinetic energy and gravitational potential energy with respect to time is zero, to obtain the derivative expression for acceleration; converting the time relationship in the derivative expression of acceleration to a radial position relationship based on the principle of conservation of angular momentum; integrating the radial position relationship to obtain the satellite's orbit equation. This method enables satellite orbit prediction.

The invention discloses a method for evaluating a safe landing area of a fast-spinning weak-gravity target, and belongs to the field of aerospace. The implementation method comprises the following steps: acquiring basic parameters of the small celestial body, wherein the basic parameters comprise a three-dimensional shape model, density, rotation axis direction, rotation angular velocity and friction angle; establishing a global coordinate system by taking the geometric center of the small celestial body model as an original point, and establishing a local coordinate system on the surface of the global coordinate system; according to the three-dimensional shape model and the density, the gravitational potential around the small celestial body is calculated, and the gravitational acceleration borne by the spacecraft at the landing point is calculated in combination with the position vector of the landing point; based on the rotation angular velocity of the small celestial body, the centrifugal force acceleration borne by the spacecraft at the landing point is calculated. And the resultant acceleration of the spacecraft in the normal direction is obtained by combining the propelling force acceleration of the spacecraft, and the friction force is calculated according to the friction angle. And calculating to obtain the dynamic characteristics of the spacecraft in different areas so as to judge whether the spacecraft can stably land or not, thereby realizing the identification of the safe landing area on the surface of the small celestial body.

The invention discloses an asteroid multilayer internal structure inversion method based on relative position measurement, and belongs to the technical field of aerospace. A multi-layer model is established for the internal structure of the differentiated asteroid, and the gravitational potential of the differentiated asteroid to an external point is calculated; an asteroid multilayer internal structure inversion system is constructed, the position and speed of a surrounding detector, the position of an attached beacon and asteroid multilayer model parameters are used as state variables, and the inversion system further comprises a state model and an observation model based on relative position measurement; unscented Kalman filter estimation is used on the premise that noise obeys Gaussian distribution, a final state variable estimation value and covariance are obtained after accumulation is conducted for a certain time, asteroid multi-layer model parameter related estimation values are extracted, and inversion of an asteroid multi-layer internal structure is achieved. According to the method, the error between a given state variable nominal value set and an obtained estimation value set is calculated, filtering parameters are optimized through error analysis, and the inversion precision of the asteroid multi-layer internal structure based on relative position measurement is further guaranteed.

The present application relates to a kind of gravity potential measurement system, method and ore body detection method, wherein the method includes: reference station optical lattice clock is used to generate reference light frequency signal;At least one mobile station optical lattice clock is used to generate local light frequency signal;Reference station optical frequency comb is used to coherently map reference light frequency signal to radio frequency band, and output reference frequency signal;Transmission link is used to coherently transfer reference frequency signal to mobile station optical frequency comb;Mobile station optical frequency comb is used to coherently restore received reference frequency signal, obtain the restored light frequency signal consistent with the frequency of reference light frequency signal, restore light frequency signal and local light frequency signal are frequency-mixed, and the frequency offset generated by gravitational redshift effect is output;Data processing module is used to convert the frequency offset into the gravitational potential difference between the position of reference station optical lattice clock and mobile station optical lattice clock.The present application can improve the reliability and practicality of gravity potential measurement.

The application discloses a kind of light frequency signal interplanetary gravity potential difference measurement methods, comprising: respectively establishing light clock light frequency comparison system on two planets needing to measure gravity potential difference, to construct planet-planet three-frequency combination light frequency comparison link;According to the planet-planet three-frequency combination light frequency comparison link constructed, bidirectional light frequency signal transmission, reception and reflection between two planets are carried out, respectively record the emission frequency f1 of planet one to planet two to planet one link, reflection frequency and receiving frequency, the emission frequency f2 and receiving frequency of link;According to the one-way frequency transmission model between stars, in combination with the frequency recorded, extract the gravitational redshift frequency shift between two planets;According to the relationship between gravitational redshift frequency shift and gravity potential difference, the gravity potential difference between two planets is calculated.

Satellite constellation limited time cooperative orbit insertion control method belongs to the technical field of deep space exploration. The method of the present application is as follows: a satellite dynamics model is established with extended orbit elements as state variables, and the model is incorporated with J2 perturbation, atmospheric resistance, third body gravity and other modelable bounded perturbations; according to the orbit dynamics model, a state space expression in the reconstruction process is constructed, and a Lyapunov type artificial potential function about the target orbit state is constructed; in order to ensure collision safety in the reconstruction process, the artificial potential field method is used, the gravitational potential function and the repulsive potential function are constructed under the target orbit and constellation configuration constraint conditions, and the time control part is added to the constructed potential function, which is used to adjust the phase change rate, so that the target phase is reached at the specified time, and then the target convergence potential function is obtained; a multi-target potential function is constructed; and a control law is solved to enable the satellite to complete the orbit insertion task under multiple constraint conditions.

The application relates to a kind of asteroid surface escape velocity calculation method considering rotation and terrain influence, comprising: obtaining the three-dimensional shape model of target asteroid and carrying out discrete, reading the vertex set and triangular facet set of polyhedron, carrying out gravity field modeling, establishing standard polyhedral gravity model;Define the logarithmic kernel function of each edge of each triangular facet, to determine the gravitational potential of target asteroid on any field point;Establish star-fixed coordinate system in standard polyhedral gravity model, determine the rotation speed of any point on the surface of target asteroid, thereby define the effective potential upper bound and the inertial system speed of the release instant of the particle on the surface of target asteroid;Based on the minimum escape condition that the kinetic energy of the particle on the surface of target asteroid is equal to the corresponding effective potential upper bound, determine the minimum normal escape velocity of the particle. Compared with the prior art, the application can quickly obtain accurate minimum escape velocity and corresponding escape direction at any surface point.

The invention provides an orbit design method for space-based observation of a low-orbit satellite constellation, belongs to the field of spacecraft orbit design, and solves the problem that a space-based observation platform is low in observation efficiency of the low-orbit satellite constellation. Comprising the following steps: combining an earth gravitational potential function with an earth non-spherical perturbative force function to obtain a J2 perturbative force function; a Kepler orbital element is used for representing a J2 perturbation function, and the J2 perturbation function is combined with a Lagrange type perturbation motion equation to construct a Lagrange perturbation model; a lagrangian perturbation model, the influence of J2 perturbation force on the number of low-orbit satellite orbits and the drift law of the right ascension of an ascending node are utilized to construct complementary angles of the orbit inclination angle of a space-based observation platform and the orbit inclination angle of a low-orbit satellite; the space-based observation platform is a retrograde orbit configuration or a plurality of retrograde orbit configurations, and the eccentricity rate and the semi-major axis of the space-based observation platform are the same as those of the low-orbit satellites, so that observation of all the low-orbit satellites in the constellation is completed; according to the invention, the observation efficiency of the space-based observation platform on the low-orbit satellite constellation is improved.

The application belongs to the technical field of space gravitational wave detection, and specifically discloses a gravitational effect finite element simulation method based on solving gravitational field partial differential equations, which comprises the following steps: inputting a weak form of the gravitational field partial differential equation in a physical field developer of simulation software COMSOL to construct a gravitational field interface plug-in; importing a spacecraft model into the simulation software COMSOL and constructing a space around the spacecraft; inputting a definite condition in the gravitational field interface plug-in; determining a gravitational potential through mesh partitioning and the gravitational field interface plug-in, and determining the gravitational field intensity of the spacecraft and the surrounding space based on the gravitational potential; and performing an integration operation on the test mass in the spacecraft based on the gravitational field intensity of the spacecraft and the surrounding space to determine the gravity and the gravity torque that the test mass receives. Through the application, the self-gravitational effect calculation process can be effectively simplified, and the gravity that an object with any shape receives can be calculated.

The application belongs to the technical field of geodetic survey and geophysical exploration, and discloses a multi-frequency multi-mode GNSS transoceanic height transfer and global height datum unification method, which comprises the following steps: 1, deploying multi-frequency multi-mode GNSS receivers at multiple local leveling / gravity joint survey points, and synchronously carrying out GNSS static observation; 2, acquiring satellite precise clock orbit products; 3, calculating the gravitational potential of the position where the satellite is located; 4, solving the elevation of the ground survey point by means of a model for determining the gravitational potential and the elevation based on single-station undifferenced multi-frequency multi-mode GNSS signals; 5, cyclically executing steps 1-4 to acquire the elevations of various transoceanic observation points; 6, obtaining the height difference between two different transoceanic survey points through difference operation; and 7, determining the height datum difference between the two different transoceanic survey points based on the least square method, so as to realize the unification of the transoceanic different height datum. The application solves the long-standing problem of transoceanic and transsea height transfer, and realizes the unification of global height datum.

The invention discloses an optical frequency signal interstellar gravitational potential difference measurement method, which comprises the following steps of: respectively establishing an optical clock optical frequency comparison system on two planets of which the gravitational potential difference needs to be measured so as to construct a planet-planet three-frequency combined optical frequency comparison link; according to the constructed planet-planet three-frequency combination optical frequency comparison link, bidirectional optical frequency signals are transmitted, received and reflected between the two planets, and the transmitting frequency f1, the reflecting frequency and the receiving frequency of the link from the first planet to the second planet to the first planet and the transmitting frequency f2 and the receiving frequency of the link are recorded respectively; according to an interstellar unidirectional frequency transfer model, in combination with each recorded frequency, extracting a gravitational red shift frequency shift between the two planets; and according to the relationship between the gravitational red shift frequency shift and the gravitational potential difference, the gravitational potential difference between the two planets is calculated.

This invention discloses a method for measuring the center of mass based on the multipole expansion of gravitational potential energy. This invention improves accuracy through joint calibration of multiple physical quantities by simultaneously measuring the changes in inertial tensor and gravitational potential energy. The specific process involves simultaneously measuring the multipole moment of gravitational potential energy and the inertial tensor. Using the multipole expansion formula of gravitational potential energy, the potential energy is expressed as a function of mass, center of mass position, and inertial tensor. The center of mass coordinates are solved by fitting multiple sets of displacement data using the least squares method. The least squares fitting method eliminates systematic errors in the calibration of single physical quantities and dynamically corrects center of mass offset errors. This method can handle asymmetric and complex shapes and is suitable for measuring the center of mass position of precision devices such as spacecraft. This invention has wide applications in the field of precision measurement technology.

The invention discloses a centroid measurement method based on gravitational potential energy multi-pole moment expansion, and the method achieves the combined calibration of multiple physical quantities through the simultaneous measurement of an inertia tensor variable quantity and a gravitational potential energy variable quantity, and improves the precision. The specific process is as follows: simultaneously measuring the multi-pole moment and inertia tensor of the gravitational potential energy, expressing the potential energy as a function of mass, centroid position and inertia tensor in combination with a multi-pole moment expansion formula of the gravitational potential energy, fitting multiple groups of displacement data through a least square method to solve centroid coordinates, and calculating the multi-pole moment of the gravitational potential energy. The system error during calibration of a single physical quantity can be eliminated by means of least square fitting, the mass center offset error is dynamically corrected, the measured object of an asymmetric complex shape can be processed, and the method is suitable for mass center position measurement of precise devices such as spacecrafts and the like. The method is widely applied to the technical field of precision measurement.

This invention discloses a method and system for determining gravitational potential using a star-space-ground optical clock time-frequency comparison system. The method for determining gravitational potential proposed in this invention uses a time-frequency comparison system with a frequency better than 110... ‑18 Using a high-precision optical clock as the foundation, and a free-space time-frequency comparison link based on optical frequency combs as the bridge, the optical clocks between space, air and ground are connected to achieve high-precision time-frequency transmission. By comparing the time and frequency of the remote clock, the gravity frequency shift signal is accurately extracted. Then, the gravity frequency shift equation is used to obtain the gravity potential difference at the location of the remote clock, and the gravity potential difference between the air and the ground or between any ground station is determined.

The invention discloses a satellite antenna virtual splicing and assembling method based on collaborative optimization of gravitational potential energy functions. The method comprises the following steps: constructing a virtual assembling initialization scene driven by multi-source data; constructing a global gravitational potential energy field based on a theoretical profile, and converting a sub-lobe geometric surface shape error into a global potential energy value; constructing a local cooperative constraint potential energy field based on a boundary topological relation, wherein the field comprises an elastic stretching potential energy component representing the gap width and a torsion potential energy component representing the order difference and normal deflection; the to-be-assembled sub-lobe is regarded as a rigid body, pose parameter differential is solved based on the total potential energy function, and a virtual resultant external force and a virtual resultant moment acting on the mass center of the sub-lobe are obtained; on the basis of the virtual resultant external force and the virtual resultant moment, synchronously updating the spatial positions and attitude angles of all sub-lobes in the opposite direction of the potential energy gradient, and recalculating the global gravitational potential energy function and the local cooperative constraint potential energy function until the total potential energy converges. According to the invention, efficient and accurate virtual splicing assembly of the satellite antenna is realized.

This invention belongs to the field of geodesy and geophysical exploration technology, and discloses a method for transoceanic elevation transfer and global elevation datum unification using multi-frequency, multi-mode GNSS. The method includes: Step 1, deploying multi-frequency, multi-mode GNSS receivers at multiple local leveling / gravity measurement points and simultaneously conducting GNSS static observations; Step 2, acquiring satellite precision clock track products; Step 3, calculating the gravitational potential at the satellite's location; Step 4, using a model for determining gravitational potential and altitude based on single-station non-differential multi-frequency, multi-mode GNSS signals to calculate the altitude of ground measurement points; Step 5, iteratively executing steps 1-4 to obtain the altitude of each transoceanic observation point; Step 6, obtaining the elevation difference between two different transoceanic measurement points through difference calculation; Step 7, determining the elevation datum difference between the two different transoceanic locations based on the least squares method, thus achieving the unification of transoceanic elevation datums. This invention overcomes the long-standing problem of transoceanic and transsea elevation transfer and achieves the unification of global elevation datums.