74 results about "Geocentric coordinates" patented technology

The invention provides a celestial autonomous navigation method based on star sensors, which comprises the following steps: calculating attitude information based on a geocentric inertial coordinate system, which is output by a star sensor; calculating the optical axis direction based on the geocentric inertial coordinate system; converting the optical axis direction based on the geocentric inertial coordinate system into optical axis direction based on a WGS84 coordinate system; reading the included angles alpha 0 and beta 0 between the X and Y directions of the star sensor and the horizontal direction from a laser level meter; calculating the direction in the WGS84 coordinate system when the optical axis direction is perpendicular to the horizontal level; calculating the longitude alpha and latitude beta of the underground point S of the carrier; and outputting the attitude q and the longitude alpha and latitude beta of the underground point of the carrier in the geocentric inertial coordinate system. The invention avoids measurement and control errors caused by horizontal reference platforms, enhances the measuring accuracy, and simultaneously outputs the attitude of three axes and the longitude and latitude of the carrier in the geographic coordinate system in real time, thereby completely realizing celestial autonomous navigation.

The invention discloses a geometric correction method for a spotlight-mode satellite SAR image. The method comprises the following steps: (1) reading related parameters and echo data, and constructing a positioning equation; (2) calculating the coordinates of the position vector and velocity vector of a satellite in a non-rotating geocentric coordinate system at a moment of radar illumination center according to the spatial geometric relationship between the satellite and the earth; (3) completing slope distance and Doppler frequency correction; (4) acquiring the coordinates as well as longitude and latitude of a certain pixel point (i, j) of the satellite SAR image in the non-rotating coordinate system; (5) determining whether all of the pixel points of the satellite SAR image are processed; and (6) re-dividing the latitude-longitude grid, and outputting the geometric correction result. The method provided by the invention can be used for carrying out row-by-row geometric correction on the satellite SAR image, and can process the satellite SAR image in blocks as required due to the completely independent treatment process between the rows of the satellite SAR image, thereby further improving the treatment efficiency.

The invention relates to a multi-sensor combined navigation system for aviation, and the system comprises an MSINS unit, a GPS unit, a magnetic compass unit, a liquid crystal display unit, a data transmission interface unit, a combined navigation computer, a data storage unit and a power supply device. The MSINS unit is used for acquiring signals of an accelerometer and a gyroscope, carrying out filtration and amplification and sending the signals to a DSP for carrying out algorithm processing; a GPS module is used for outputting longitude, latitude, altitude and velocity values of X, Y and Z axes based on a geocentric coordinate system measured by the GPS; the magnetic compass unit is used for outputting three-dimensional attitude information measured by a three-axis magnetic compass; the combined navigation computer is used for receiving signals outputted by an inertial measurement unit, the GPS module and the magnetic compass, applying the federated Kalman filtering algorithm to carry out fusion treatment on data and obtaining combined navigation data; and the data storage unit is used for saving original data and result data. The system has the advantages of small volume, low cost, high reliability and high precision.

The invention relates to the field of radio navigation and, more specifically, it relates to methods of determining the current values of the orbital position of the artificial satellite of the Earth which is used in a satellite radio navigation system (SRNS), by the ephemeredes and can be used when performing the radio navigation measurements in the equipment of the consumers of the SRNS signals. The variants of a fast method for determining the coordinates of the satellite are proposed, which consist in that the satellite coordinates are determined at preset points of the orbit spaced from each other by a selected time interval, and further determining the velocities of the satellite at the nodal points, while at the points between the nodal points the satellite coordinate are determined in the geocentric inertial system of coordinates are in a system the Greenwich geocentric coordinates using special formulas or the Taylor polynomial of the second or third order, and determining these at the nodal points using the six-order Taylor polynomial.

The invention discloses a satellite autonomous navigation system and a satellite autonomous navigation method integrating a pulsar radiation vector and timing observation. The system obtains pulse arrival time and accurately obtains a pulsar radiation direction vector by using a time distinguishing detector and a collimator, and obtains a geocentric direction vector by using an infrared or ultraviolet horizon sensor; a navigation computer respectively completes a pulsar timing observation navigation algorithm under a geocentric coordinate system, a pulsar positioning algorithm based on angular distance measurement and a geometric orientation algorithm based on angular distance measurement by using the pulsar pulse arrival time, the radiation direction vector and the geocentric direction vector, and obtains the position, the speed, the attitude and the on-track movement direction of a spacecraft through integration of several algorithms, so as to complete the autonomous navigation of an orbiting satellite, and output high-precision position, attitude and speed information. The system is suitable for autonomous operation control of orbiting satellites or constellations of the earth or other planets.

The invention relates to a one-stop calibration method for arrangement parameters of a vehicle-mounted three-dimensional laser scanning system. The one-stop calibration method comprises the steps of fixing a certain number of artificial marks with a reflective property on objects in a calibration field, and acquiring geocentric coordinates of the artificial mark points; selecting a position where the mark points are distributed to act as a site, enabling a vehicle loaded with the three-dimensional laser scanning system to stop at the site, acquiring a series of mark point clouds by using a three-dimensional acquisition mode, carrying out recognition and positioning on the mark point clouds, and establishing the mark point clouds in a laser scanning coordinate system L; and transforming the geocentric coordinates of the artificial marks from a geocentric coordinate system (WGS84) to an inertial platform coordinate system (I) through coordinate transformation mode, realizing conversion with coordinates in the laser scanning coordinate system (L) through a coordinate transformation model, and solving the arrangement parameters. The method provided by the invention can carry out calibration at one stop, thereby reducing the complexity of a mathematical transformation model, and improving the efficiency of calibration for the arrangement parameters.

The invention discloses a method based on satellite communication for identifying deception jamming acting on navigation data of an unmanned plane. The method comprises the steps: firstly, establishing a geocentric coordinate system, a plane body coordinate system and a geodetic coordinate system associated with an unmanned plane; secondly, obtaining transformation relations among the coordinate systems; thirdly, obtaining the azimuth and the pitch angle of a satellite in the plane body coordinate system in a way that an unmanned plane antenna tracks the satellite according to error voltages generated during tracking of the antenna; fourthly, calculating the geodetic azimuth and the pitch angle of the satellite in a point where the geodetic coordinate system of the plane is located according to the azimuth, the pitch angle and the roll angle of the plane measured through inertial navigation; and deducing a longitude [phi]Lon and a latitude [theta]Lat of the plane according to the geodetic azimuth and the pitch angle of the satellite in the point where the geodetic coordinate system of the plane is located. The method can identify whether navigation data is deceptive by means of an existing satellite communication system with no need of other auxiliary devices.

The invention relates to an augmented reality method based on topocentric coordinate system and perspective projection. The augmented reality method based on the topocentric coordinate system and perspective projection includes that (1) coordinate transformation, to be specific, converting geodetic coordinates of mobile equipment and an interest point into geocentric coordinates to obtain the coordinates of the interest point in the topocentric coordinate system to obtain the perspective coordinates of the interest point; (2) perspective projection, to be specific, perspectively projecting the topocentric coordinates of the interest point relative to the current position of a user to a display screen of the mobile equipment, using a mobile equipment camera to perform location shooting, and overlapping the relevant information of the interest point to the position of the interest point in the scenery shot by the camera of the mobile equipment according to different orientations of the mobile equipment. The augmented reality method based on the topocentric coordinate system and perspective projection overcomes the disadvantage that the traditional map and navigation application are not intuitive; the augmented reality method based on the topocentric coordinate system and perspective projection quickly finds the interest point, and the relevant information of the interest point is timely overlapped to the interest point in the shot image to present the intuitive effect; the augmented reality method based on the topocentric coordinate system and perspective projection automatically prompts the current direction of the user and quickly and precisely obtains the direction and position of the interest point relative to the current position of the user.

The invention discloses a spacecraft attitude and position measurement system and method based on an X-ray pulsar. According to the system, a satellite-borne X-ray detector is matched with a collimator to acquire pulse arrival time and accurately acquire a pulsar radiation direction vector, and a geocentric direction vector is acquired by virtue of an infrared or ultraviolet horizon sensor; a navigational computer finishes a pulsar timing observation navigation algorithm, a pulsar positioning algorithm based on angular distance measurement and a pulsar fixed attitude algorithm based on angular distance measurement respectively under a geocentric coordinate system and acquires the position, speed, attitude and in-orbit movement direction of a spacecraft in real time through the several algorithms according to the pulse arrival time, the radiation direction vector and the geocentric direction vector, the autonomous navigation of an orbiting satellite is finished, and high-precision position, attitude and speed information is output. The system is applied to autonomous control on orbiting satellites or constellations of the earth or other planets.

The invention relates to an automatic tracking method of an airborne downward-looking measurement target. The method includes the following steps that: S1, the location information of an aircraft and the target are obtained, and the first coordinates of the target after the origin of a geocentric coordinates system is shifted to the location of the aircraft is determined according to the location information; S2, the attitude information of the aircraft is obtained, the first coordinates of the target are converted into fourth coordinates in an aircraft body downward coordinate system according to the attitude information; and S3, the azimuth angle and pitching angle of a radar antenna are determined based on the fourth coordinates of the target, and the pointing direction of the radar antenna is adjusted according to the azimuth angle and pitching angle. With the automatic tracking method of the invention adopted, the pointing direction of the beams of the antenna can be automatically adjusted in real time, and it can be ensured that the measured target is always at the center of the main beams of the antenna, and a servo control rod is not required to be manually operated to align the target, and therefore, the efficiency and accuracy of airborne downward-looking measurement can be significantly improved.

Aimed at the current situation of poor on-orbit absolute radiometric calibration precision, the invention provides an on-orbit absolute radiometric calibration method based on a benchmark satellite. Sunlight with appropriate intensity is reflected onto a to-be-calibrated remote sensor by a diffuse reflection plate on a benchmark satellite, the influence of atmospheric conditions on a radiation transfer path is got rid of, an accurate apparent radiance is obtained, and thereby an accurate absolute calibration coefficient is obtained. In the invention, the sun, the benchmark satellite and the to-be-calibrated remote sensor are integrated into a geocentric coordinate system, so that the distance between each two of the three and the incidence angle and emergence angle of sunlight on the surface of the diffuse reflection plate on the benchmark satellite can be conveniently obtained, a radiation transfer link model from the sun to the benchmark satellite and to the to-be-calibrated remote sensor is created, and finally, calibration is complete.

The invention relates to the navigation data field and provides a positioning method, device and terminal of a target point on a map. The method comprises the following steps of selecting a referencepoint in a geocentric coordinate system to establish a reference coordinate system; obtaining a first coordinate conversion relationship of the geocentric coordinate system to the reference coordinatesystem; obtaining a second coordinate conversion relationship of the reference coordinate system to a three-dimensional space coordinate system; obtaining vector information of a reference point to the target point in the reference coordinate system according to positioning information of the reference point and the target point in the geocentric coordinate system, and the first coordinate conversion relationship; and converting the vector information through the second coordinate conversion relationship, and acquiring the positioning information of the target point in the three-dimensional space coordinate system. In the method, a coordinate point of the reference coordinate system and the coordinate point of the three-dimensional space coordinate system are converted, and a coordinate system type is unified, a coordinate conversion step is simplified, participation in conversion of constants such as an Earth ellipsoid parameter and the like is avoided, and a deviation of a relativeposition of objects in an adjacent area due to conversion is reduced.

The invention discloses an initial attitude acquisition method for a ground test for soft lunar landing by using a SINS (serial inertial navigation system), and belongs to the field of lunar exploration. The method comprises the following specific steps: firstly, arranging a fixed azimuth mirror near a test field, and by adopting the azimuth mirror for buffering, obtaining an attitude transformation matrix of a tester control coordinate system relative to a sky northeast coordinate system of the test field; then, through a geographical latitude of an observation point of the test field, obtaining a transformation matrix of the sky northeast coordinate system of the test field relative to a geocentric coordinate system, so that a transformation matrix C6 of the tester control coordinate system relative to the geocentric coordinate system is obtained, and then an attitude Q0 quaternion at an initial time T0 is obtained finally; starting from the initial time T0, carrying out attitude extrapolation by using gyro measurement data; and obtaining an attitude Qk during a k(th) control period, carrying out real-time output on the Qk until the tester attitude extrapolation process is completed and a landing test begins, wherein the Qk at the moment is taken as an initial attitude of a tester. The method disclosed by the invention is applicable to the ground test for lunar landing.

The invention discloses a BIM data lightweight method. The method comprises the following steps of S1, converting original BIM data into IFC data of a standard unit; S2, converting the BIM data underthe custom rectangular coordinate system into a corresponding local coordinate system; s3, converting the BIM data under the local coordinate system into a reference center plane coordinate system; and S4, converting the BIM data in the reference center plane coordinate system into BIM data in a 3DTiles format in a geocentric coordinate system, and outputting the BIM data in the 3DTiles format. The beneficial effects of the invention are that the method focuses on a business problem rather than a bottom-layer technical problem, supports the integration and fusion of various types of source heterogeneous data, guarantees the integrity and accuracy of the data, solves a problem that the current BIM data is difficult to share and manage efficiently, and provides a technical basis for the construction of a three-dimensional smart city.

The invention provides a tower crane control method and system. The tower crane control method includes the steps that data information of a base station, a tower crane and a destination are obtainedby GPS satellite transmitting signals received by the base station installed on a measuring area and mobile receiving stations arranged on the tower crane and the transportation destination correspondingly; phase difference processing is carried out according to the data information of the base station and the data information of the tower crane and the transportation destination, and longitude and latitude coordinates of the tower crane and the transportation destination in a geocentric coordinate system WGS-84 are obtained; and the longitude and latitude coordinates of the tower crane and the transportation destination in the geocentric coordinate system WGS-84are converted into spatial rectangular coordinates to obtain a starting three-dimensional coordinate of the tower crane and a final three-dimensional coordinate of the transportation destination, and after calculating operation parameters of the tower crane, a control instruction is sent to a control circuit of the tower craneto remotely control operation of the tower crane. According to the tower crane control method and system, through positioning and coordinate converting of the tower crane and the transportation destination of goods, operation of the tower crane is remotely controlled according to the coordinates, no need to manually drive the tower crane, the risk of tower crane operation is reduced, and the positioning accuracy is high.

The invention discloses a borehole positioning method based on the earth ellipse sphere. The borehole positioning method comprises obtaining the geodetic coordinates of the wellhead and the target point; determining the north-seeking standard and the wellhead coordinate system; calculating the geocentric coordinates of the wellhead and the target point; calculating the target point coordinate in the wellhead coordinate system; and designing the borehole trajectory. Because the influence of the curve of the earth ellipsoid surface is considered, and map projection and projection transformation problems are not involved, errors caused by map projection deformation and concomitant various error risks are eliminated, and therefore the precision and the reliability of borehole positioning and borehole trajectory designing can be substantially improved.

The invention discloses a low-altitude target detection method and system based on a multi-source detector. The method comprises the steps that each detection station device detects and measures the distance of an obtained image of a target appearing in a view field; the position information of the target relative to each detection station device then is acquired; each detection station device uploads detected target position information to the command and control subsystem; the command and control subsystem determines a target geocentric coordinate system coordinate in combination with the target position information uploaded by each detection station device, converts the target geocentric coordinate into target GPS information, and converts the target GPS information into angle information of the target relative to each detection station device; the command and control subsystem determines that the detected target meets a preset requirement according to the target GPS information; and the angle information of the target relative to each detection station device is issued to a processing subsystem, and the processing subsystem is linked with the detection station device which stably tracks the target so that the target is enabled to be always stably located in the action area of the processing subsystem.

The invention discloses an MEMS (micro-electromechanical system) pressure sensor-based collaborative satellite positioning method and system. The method comprises the following steps that: a navigator obtains the satellite instantaneous geocentric coordinates of four satellites through using ephemeris broadcasted by the satellites, and the navigator, based on the conversion relationship of geocentric coordinates and geodetic coordinates, builds a pseudorange observation equation corresponding to each of the four satellites through using the pseudorange observation quantities of the satellites with the geodetic coordinate system of the navigator adopted as a solving objective; geodetic coordinate-based height information is obtained based on an MEMS pressure sensor, and an elevation information constraint equation is established based on the height information; and the current geodetic coordinate solving model of the navigator is formed based on the pseudorange observation equation and the elevation information constraint equation, and the geocentric coordinates of the navigator are obtained based on the conversion relationship of the geocentric coordinates and the geodetic coordinates. According to the MEMS (micro-electromechanical system) pressure sensor-based collaborative satellite positioning method and system provided by the embodiments of the invention, the MEMS pressure sensor and the satellite signals are combined to perform positioning, and therefore, a collaborative positioning function is realized under a condition that satellite signal difference or only four satellites exist.

The invention relates to a disc projection and splicing method for large view field space to ground observation images and belongs to the space remote sensing detection technology field. The method mainly comprises steps that a conversion matrix between a geocentric coordinate system GEO and a projection disc coordinate system OPC is calculated; a disc projection grid is established on a reference spherical surface in the OPC coordinate system; latitudes and longitudes of grid points and a grid center point are calculated and are then further converted to the GEO coordinate system; the actual projected image point number of two-dimensional array Np storage grid points and a main intensity value of actual projected image points of the two-dimensional array Np storage grid points are calculated; a look vector under each image point satellite coordinate system is calculated and is gradually converted to the OPC coordinate system, and a projection image data matrix, a grid point geographical latitude and longitude data matrix and a grid point center geographical latitude and longitude data matrix are lastly acquired. The method is advantaged in that time sequence observation images are projected and spliced to one grid of the reference spherical surface, so spatial distribution of observation objects can be actually and accurately described through the projection images.

The invention discloses a realistic simulation method for satellite signals. The method comprises the following steps of radio frequency interference simulation, environment noise simulation, ionizedlayer error simulation, troposphere error simulation and error introduction simulation calculation. The method has the advantages that errors and interference of a satellite propagation process are divided into radio frequency interference, environmental noise, ionized layer errors and troposphere errors through the method, and the errors and the interference are simulated through a mathematical method and finally introduced into satellite propagation simulation calculation, so that the propagation simulation process of the satellite signals is more consistent with real situations; satellite position and speed are calculated through an earth-centered earth-fixed coordinate system, and different earth-centered earth-fixed coordinates are adopted according to different satellite types so that different satellites can use more targeted mathematical models to obtain more real simulation results.

The invention provides a method and device for constructing a motion model of a framework site of a geocentric coordinate system, and relates to the technical field of coordinate frameworks of the geocentric coordinate system and geodetic datum maintenance. The method comprises the steps that an original three-dimensional coordinate time sequence of the framework site of the geocentric coordinate system is acquired; the original three-dimensional coordinate time sequence is analyzed, a first missing point and a second missing point are determined, the first missing point and the second missing point are subjected to three-dimensional coordinate data interpolation processing, and the three-dimensional coordinate time sequence after interpolation processing is obtained, wherein the first missing point is a time point corresponding to three-dimensional coordinate data which has gross errors, and the second missing point is a time point which lacks the three-dimensional coordinate data in a preset time sequence; based on the three-dimensional coordinate time sequence after interpolation processing, the motion model of the framework site of the geocentric coordinate system is constructed through the multichannel singular spectrum analysis theory. According to the method and device, the technical problem of low precision in the prior art of constructing the geocentric coordinate frameworks is solved.

The invention relates to an offshore exploration well point rapid positioning method and device, electronic equipment and a storage medium. The method comprises the following steps of S1, acquiring known parameters of an offshore exploration well point, wherein the known parameters comprise design coordinates of a design target point and positioning coordinates of a positioning target point undera geocentric coordinate system; S2, performing operation processing according to the well point parameters to obtain target data; S3, obtaining an error result of the positioning coordinates and the design coordinates according to the target data, and completing the positioning of the well point according to the error result. By implementing the method, the error result of the positioning target and the design target can be quickly determined; therefore, the explored well point can be quickly positioned according to an error result; the offshore drilling positioning feedback speed is effectively increased, the operation efficiency is improved, the feedback time is greatly shortened to reduce the waste cost when a drilling ship waits, meanwhile, whether the geological design requirement ismet or not can be rapidly checked according to the error result, and possible problems can be found in time.