39 results about "Reference ellipsoid" patented technology

The invention discloses an SAR interference baseline precise estimating method based on a flat-earth phase. The method comprises the steps that according to the geometrical relationship of an SAR interference baseline and the flat-earth phase, a rigorous SAR interference baseline estimating adjustment model is built, the geometric structure of baseline estimation is transferred to a regular reference ellipsoid face from the fluctuant and changing earth surface, and an iterative unknown parameter solution algorithm combining ridge estimation and truncated singular value decomposition is provided. According to the SAR interference baseline precise estimating method, the survey adjustment theory and an InSAR theory are organically combined, and the method comprises the following steps of (1) data preprocessing, (2) systemic signal removal, (3) model building and (4) model resolving. The SAR interference baseline precise estimating method is visual in principle, facilitates programming realization and application, is stable and reliable and can be used for improving the precision of measurement of the InSAR technology.

The invention discloses a geoid-vertical line deviation correction method and system for a GNSS-R specular reflection point. The method comprises the steps of acquiring spatial position information ofnavigation satellites and a receiver; determining a specular reflection point on the reference ellipsoid according to the spatial position information of the navigation satellites and the receiver; introducing the elevation correction amount, iteratively correcting the specular reflection point on the reference ellipsoid to the geoid to obtain a specular reflection point on the geoid; calculatingthe spatial geometric relationship between the normal projection of the geoid and the reflection path, determining the vertical line deviation correction amount of the specular reflection point, anditeratively correcting the normal direction of the reflection path to the normal direction of the geoid, and carrying out iterative correction on the specular reflection point on the geoid to obtain afinal specular reflection point corrected by the vertical line deviation on the geoid. The geoid-vertical line deviation correction method and system improve the positioning accuracy of the specularreflection point and provide support for acquiring a marine gravity field with high spatial resolution and high precision.

The invention requests to protect a method for obtaining an independent city coordinate system parameter based on geographic information application, and relates to a method for calculating an approximate parameter of an independent city coordinate system by using a gauss projection technology, so as to achieve inter-conversion of geographic information results. A unitary polynomial equation concerned with a central meridian L0 of the independent coordinate system is simplified by obtaining three same point results of one independent city coordinate system and the national general coordinate system and transforming a gauss projection normal calculation formula; the central meridian L0 can be resolved by using an iteration method, so as to calculate other parameters of the independent coordinate system; the other parameters include reference ellipsoid long radius a, the central meridian L0, north direction offset X0 and east direction offset Y0. Thus, conversion and application of the same point results between the independent coordinate system and the national general coordinate system can be achieved. The method can be widely applied to conversion and application of geographic space information coordinates in construction of geographic spatial data, digital city construction and the like.

The invention discloses a disturbing gravity-based quasi-geoid land-sea seamless splicing method. In the method, the physical characteristic that the disturbing gravity is not limited by local height datum is fully utilized, a unified earth reference ellipsoid is taken as a coordinate reference frame, the land-sea unified disturbing gravity is calculated by adopting land-sea reference unified global navigation satellite system (GNSS) and gravity data, and the land-sea unified disturbing gravity is introduced to the more strict arithmetic provided by the invention so as to realize quasi-geoid land-sea seamless splicing. Different from the conventional fit algorithm for calculating land-sea height anomaly by utilizing gravity anomaly and a Stokes formula, the method is strict theoretically, and can eliminate result errors caused by the oddness of a kernel function.

The invention provides an applicability discrimination method for a coordinate transformation model. The applicability discrimination method comprises the following steps: comparing transformation coordinates generated by a common transformation model by using a side length difference and an azimuth angle difference model of a CGCS2000 geodetic coordinate system and a national reference-ellipsoid-centric coordinate system; carrying out check analysis on the characteristics of the transformation model by using a side length difference and an azimuth angle difference according to the variation quantity and the variation trend; verifying data by using two stages of GPS (Global Positioning System) control networks in one region to reflect the characteristics of the transformation model; verifying the characteristics of the transformation coordinates by utilizing data of the GPS control network and transforming between the CGCS2000 geodetic coordinate system and the national reference-ellipsoid-centric coordinate system. According to the applicability discrimination method provided by the invention, the problem of difficult model selection for different demands in the coordination transformation process is solved, the problems that the precision is evaluated by completely depending on transformation residual and the precision estimation of the transformation residual has certain limitation in the previous coordinate transformation are solved, vast transformation workload is avoided, a large amount of cost and time are reduced and saved, and popularization and application of the CGCS2000 geodetic coordinate system are facilitated.

The invention relates to a network RTK (Real-Time Kinematic) positioning method for obtaining coordinates and normal height of a reference-ellipsoid-centric coordinate system in real time. Source nodes are expanded and are used for transmitting the demand of a moving station in a more detailed manner, the NTRIP (Networked Transport of RTCM via Internet Protocol) is not required to be modified, judgment and an algorithm are only required to be correspondingly added into NtripCaster software or an NtripProxy relay module is only required to be added between NtripCaster and the moving station, and the method is easy to realize; if the coordinates of the reference-ellipsoid-centric coordinate system are required to be obtained in real time, the corresponding source node is only required to be selected during logging-in to a server, non-secret-involved seven parameters are filled in a handbook and other operation modes are unchanged; if the moving station needs to obtain the normal height, the corresponding source node is only required to be selected during logging-in to the server and other operation modes are unchanged; and on the premise that the state privacy policies are complied, the goals of measuring and staking out the coordinates and the normal height of the reference-ellipsoid-centric coordinate system in real time are realized.

The invention discloses a compensation elevation plane or mean elevation plane-based 3-degree zoning coordinate conversion system. By research on a geodetic coordinate change law of a control point ona reference ellipsoid, a compensation elevation plane or a testing zone and a mean elevation plane of a city, a calculation method for a semi-major axis of a new ellipsoid after adoption of the compensation elevation plane or the testing zone and the mean elevation plane of the city, a calculation method for a geodetic latitude correction number and new geodetic latitude of the ground control point, and a calculation method for calculating direct and inverse computation parameters by taking the compensation elevation plane or the testing zone, the mean elevation plane of the city, the semi-major axis of the ellipsoid and first eccentricity as arguments are derived. Compared with the prior art, the control point is transferred to the compensation elevation plane or the testing zone and themean elevation plane of the city from the CGCS2000 ellipsoid according to calculation formulae for the direct and inverse computation parameters; high-precision coordinate conversion of geodetic coordinates and plane coordinates can be realized; and a conversion mode is also suitable for a 1980 Xi an coordinate system, a 1954 Beijing coordinate system and local independent coordinate systems.

A method based on NTRIP for measuring an RTD of an arbitrary coordinate system result carries out extension on a source node, is used for conveying moving station requests with details, does not need to modify NTRIP, and simply needs to add judgments and algorithms to NtripCaster software, or adds an NtripProxy relay module between NtripCaster and a moving station. A coordinate under a reference-ellipsoid-centric coordinate system needs to be acquired in real time, a corresponding source node simply needs to be selected when a server is logged in, and non-secret seven parameters are filled in a handhold notebook. If normal height needs to be acquired in real time, a corresponding source node simply needs to be selected when the server is logged in. If ECEF coordinate needs to be obtained in real time, a corresponding source node simply needs to be selected when the server is logged in. An operating mode is basically unchanged, under the premise that a privacy policy is met, the reference-ellipsoid-centric coordinate system and the normal height of real-time survey staking of the RTD can be achieved, and surveying and mapping production efficiency is remarkably improved.

The invention discloses a railway center line measuring and setting method based on a reference ellipsoidal surface. The railway center line measuring and setting method comprises the following steps:S1, determining starting point information, end point information and intersection point information of a railway line; S2, calculating curve comprehensive elements by utilizing a geometric analysismethod; S3, calculating mileage of each main point of the curve according to the comprehensive elements of the curve; S4, comparing the mileage of each measuring point with the numerical value of themileage of each main point of the curve, and determining a line segment to which each measuring point belongs; S5, calculating ellipsoid coordinates of each measuring point; and S6, according to the ellipsoid coordinates of all the measuring points, conducting railway center line measuring and setting. By adopting the technical scheme provided by the invention, the longitude and latitude of each point of the railway midline on the reference ellipsoid can be directly used for measurement and setting, so that the measurement and calculation result has no projection deformation or the deformationis minimized. And results on various projection planes can be obtained by referring to data obtained by calculation on the ellipsoidal surface according to various projection rules, so that the calculation data has reusability and universality.

The invention relates to a data processing method for processing data projection deformation, aiming to reduce error effectively and control the error within an effective data range. The data processing method includes the steps of 1), converting a field measurement side length into deformation generated on a reference ellipsoid surface, namely an elevation naturalization value deltaS1 so as to obtain a relation between the deltaS1 and S; 2), projecting the length on the reference ellipsoid surface to a Gauss plane, namely a Gauss deformation value deltaS2 so as to obtain a relation between the deltaS2 and S1; 3), taking S=S1 so as to obtain a relation between total length deformation deltaS and S; 4), compensating an elevation surface; 5), compensating a compensating zone applicable to the elevation.

The invention discloses a method for determining ellipsoid parameters based on an area GNSS and precise distance measurement scale ratio estimation method. The area GNSS and precise distance measurement scale ratio estimation method includes defining of a scale ratio, determining of a weighted scale ratio, a scale ratio difference analysis method and scale ratio difference estimation, and the method can solve the problem that due to influence of factors such as atmospheric refraction, a scale change is caused; and to determine reference ellipsoid parameters based on the estimation method can achieve relatively high outer coincidence precision, the method provided by the invention is simple and easy to implement, and is relatively effective for a small region of an engineering surveying control network jointly established by adoption of GNSS measurement and a short-distance precise distance measurement method.

The invention relates to the technical field of submarine topographic measurement, in particular to a submarine topographic measurement method based on a precision POS. The submarine topographic measurement method aims to collect the three-dimensional coordinate information of a hull measurement system by the precision POS composed of a GNSS receiver, an attitude instrument and a depth sounding instrument based on high-precision GNSS positioning. A reference ellipsoid surface is taken as the reference when calculating three-dimensional coordinates of measuring points. A WGS-84 coordinate system is adopted uniformly to solve the problem that the accuracy of measurement results is affected by matching of the plane position and depth information, water level control, water depth reduction andthe like in traditional water depth measurement work.

The invention discloses an ocean tide correction positioning method and system of a satellite-borne GNS-R specular reflection point. The method includes: acquiring spatial position information of a navigation satellite and a receiver; determining a specular reflection point S on a reference ellipsoid according to the obtained spatial position information of the navigation satellite and the receiver; acquiring a static elevation correction amount and a time-varying elevation correction amount; on the basis of the static elevation correction amount and the time-varying elevation correction amount, carrying out static elevation correction and the time-varying elevation correction on the specular reflection point S on the reference ellipsoid to obtain a specular reflection point S'on an oceantidal surface; and carrying out normal correction on the specular reflection point S' on the ocean tidal surface to obtain a position S'of the specular reflection point S'on the ocean tidal surface ona normal vertical plane of the ocean tidal plane. Therefore, the sea surface positioning accuracy of the satellite-borne GNSS-R specular reflection point is improved.

The invention relates to a polar region inertial navigation method based on a virtual ball normal vector model. The method comprises steps of initial navigation parameters being bound, and the real-time data information from an IMU inertial measurement unit and an altimeter being received; establishing a virtual ball normal vector model, and completing quaternion-based position representation andnavigation parameter conversion; establishing a differential equation based on the position, speed and attitude of the virtual ball normal vector model under the earth-centered earth-fixed coordinatesystem, and completing the calculation of navigation parameters according to the data information received in real time; and converting the navigation parameters under the earth-centered earth-fixed coordinate system into required navigation parameters under the coordinate system and outputting the required navigation parameters. The quadruple position representation method has global applicability, and avoids complex switching between a polar region and a non-polar region in a traditional scheme. The method only relates to accurate curvature radius calculation of the meridian circle and the mortise unitary circle in the reference ellipsoid model, an error problem caused by approximate curvature radius calculation under the reference ellipsoid model in a traditional method is avoided, andcalculation precision is improved.

The invention provides an ellipsoidal layered atmospheric refraction-based optical satellite image accurate ground positioning method. The method comprises the following steps of establishing a corresponding relationship between the height of any global point and an atmospheric refraction index; determining an intersection point of the incident light vector and the reference ellipsoid of the nextlayer according to the light initial point, and determining a refracted light vector on the next layer; gradually reducing the height of the positioning point by finely layering the atmosphere, and iteratively resolving the intersection point of the light ray and the reference ellipsoid until the intersection point is intersected with the real terrain surface to obtain the optical satellite imageaccurate ground positioning point based on ellipsoid layering atmospheric refraction. According to the method, the atmospheric refraction processing is provided, the ground point coordinates are moreaccurate, the layered refraction light vectors under the influence of atmospheric refraction are accurately extracted by calculating the normal vector of the reference ellipsoid at the refraction point, and the method is achieved through an atmospheric fine layering and gradual iterative solution mode, so that implementation is easy and convenient, and the positioning precision is high.

The invention relates to a tide gauge station vertical reference detection method using GNSS buoys, and belongs to the technical field of tide gauge station vertical reference detection. The method comprises the following steps of S1, GNSS precision level measurement, S2, GNSS buoy on-site laying, S3, GNSS static reference station erection, S4, GNSS observation time setting, S5, GNSS buoy SSH calculation, S6, tide signal SSH data filtering, S7, SSH geoid difference elimination, and S8, unification of GNSS and tide inspection station vertical standards. The high-precision GNSS height measurement buoys are used for observing sea surface height information under the WGS-84 reference ellipsoid benchmark, the three problems are avoided, the high-precision GNSS height measurement buoys are conveniently and economically arranged in a sea area near an ocean station, accumulation of benchmark displacement errors and level measurement errors of a tide station is avoided, and tide station benchmark unification is carried out in any sea area (including an offshore island reef area).

The projector type vehicle headlamp includes a light source, a reflector including a reflection surface for reflecting light from the light source, and a condenser lens that irradiates reflected light from the reflection surface forwards. The reflection surface includes a plurality of segments, and is formed of a free-form surface obtained by deforming a reference ellipsoid of revolution. The light source is arranged between a first focal point of the reference ellipsoid of revolution and the condenser lens, closer to the first focal point than to the condenser lens. Segments forming one end and other end portions of a light distribution pattern includes a wide area-illuminating reflection surface that makes the one end and the other end portions substantially a rectangular shape, where the other end portion is opposite to the one end portion with respect to a center of the light distribution pattern.

The invention discloses a factor graph integrated navigation method based on high-precision inertial pre-integration, which comprises the following steps of modeling the earth rotation angular rate and the influence of the rotation angular rate of a navigation system and an earth coordinate system caused by carrier motion into a traditional inertial pre-integration model, simultaneously considering the influence of an earth reference ellipsoid, and calculating to obtain a high-precision inertia pre-integration error transfer equation. On the basis, navigation information output by the IMU is fused with navigation information provided by other measurement sensors through an optimization theory based on a factor graph model. Optimization solution is then carried out to obtain the navigation information of the carrier. The method can effectively solve the problem that the precision of the navigation system is reduced due to the fact that a traditional factor graph integrated navigation system based on an inertia pre-integration method is inaccurate in modeling of inertia output information, and can be applied to various factor graph integrated navigation systems based on high-precision inertial devices.

The invention discloses an inertia and ADS height fusion method based on air pressure reference self-adaptive correction, and the method comprises the steps: designing a self-adaptive correction strategy for solving the problem that the air pressure height outputted by an air data system ADS is suddenly changed due to air pressure reference switching in a full leg range, and guaranteeing the smooth transition during the air pressure reference switching; the height reference in the vertical direction is unified, it is ensured that height measurement information of an inertial navigation system (INS) and height measurement information of an atmosphere data system are both based on a WGS-84 reference ellipsoid, and a foundation is laid for multi-source navigation information fusion; through combined navigation, effective fusion of multi-source height information in the vertical direction is realized. The method improves the navigation precision of the navigation system in the aviation field in the vertical direction of the full flight segment, and can guarantee the safe flight of an aircraft.

The invention discloses a satellite-borne GNSS-R mirror reflection point calculation method based on ellipsoid transformation. The method comprises the steps of determining the geodetic height of a general mirror reflection point through a digital elevation model (DEM) or a sea surface topography model, modifying the major semi-axis value of an ellipsoid through the geodetic height, constructing a new reference ellipsoid, and taking the new reference ellipsoid as a reference, and determining the mirror reflection point according to the navigation satellite position, the GNSS-R satellite position and the Fresnel reflection law, and improving the positioning precision of the mirror reflection point.

The invention discloses a railway engineering earthwork calculation method based on an engineering reference ellipsoidal surface. The method comprises the following steps: S1, measuring a middle pilecross section of to-be-calculated railway engineering earthwork; S2, calculating areas of two adjacent pile number cross sections of the middle pile cross section by adopting a product distance methodor a coordinate method; and S3, calculating the earthwork volume of the railway engineering by adopting an average section method or a prismoid method. Compared with an existing method for calculating the earthwork volume of the railway engineering, the method of the invention has the following advantages: the engineering reference ellipsoidal surface serves as a calculation surface, so that theinfluence of projection deformation can be avoided or reduced, and results on various projection surfaces can be obtained from data obtained through calculation on the engineering reference ellipsoidal surface according to various projection rules. By adopting the technical scheme to calculate the earthwork of the railway engineering, no projection deformation or minimum deformation of a measurement and calculation result can be achieved, and conversion and deformation calculation of various data on the reference ellipsoid are integrated, so that the calculation data has reusability and universality.

The invention discloses a GNSS-R sea surface height measurement precision and along-track spatial resolution reconstruction method and system. The method comprises steps that original data is processed, and a complex waveform is obtained; the complex waveform is processed to obtain a power waveform, and resolving is carried out to obtain the average height measurement accuracy corresponding to the N mirror surface points; the mirror point time delay is corrected, a vertical distance from the sub-satellite point sea surface of the receiver to the reference ellipsoid surface is obtained through inversion, and average height measurement accuracy corresponding to the N mirror points is obtained through calculation; average height measurement precision and average height measurement accuracy obtained at different signal processing times are obtained; reconstruction of GNSS-R sea surface height measurement precision and along-track spatial resolution is realized by combining the relationship between the along-track spatial resolution and signal processing time. According to the method, the relation between the airborne iGNSS-R height measurement precision and the along-track spatial resolution is comprehensively analyzed from two aspects of height measurement precision and accuracy, and a reference is provided for balance consideration of relevant parameters of a satellite-borne iGNSS-R height measurement task in the future.