34 results about "Geopotential model" patented technology

The invention relates to a submarine navigation method and system based on a multi-dimensional gravity gradient lighthouse. The method includes obtaining the position of a position point in the ocean; according to the position point, using a high-precision gravity field model to determine the ocean gravity gradient data; screening the ocean gravity gradient data to determine the gravity gradient lighthouse; acquiring the position of the current sea area and the submarine Determine the matching gravity gradient lighthouse according to the gravity gradient lighthouse database, the position of the current sea area and the current position of the submarine; determine the position of the submarine according to the ocean gravity gradient data measured by the matching gravity gradient lighthouse and the on-board gradient gravimeter; Reset the inertial navigation system based on the submarine's position. The invention provides a submarine navigation method and system based on a multi-dimensional gravity gradient lighthouse, which can improve the safety and accuracy of gravity lighthouse navigation in a gentle gravity area.

The invention provides a GPS leveling height transfer method, which comprises the following steps of: S1: creating a regional gravity quasigeoid model based on the Molodensky theory according to ground gravity observation data by combining with a regional digital terrain model and a global gravity field model; S2, obtaining a reference system difference between a GPS geodetic height and a leveling height and a height anomaly correction term influenced by the reference system difference through a GPS leveling overdetermined boundary value method, and creating a practical quasigeoid model according to the gravity quasigeoid model, the height anomaly correction term and the preset GPS leveling height anomaly system deviation; S3, obtaining a normal height of a pointed to be measured of a region to be measured according to the gravity observation data and the practical quasigeoid model. The method can implement that the GPS leveling replaces a trigonometric leveling or a conventional leveling to meet the transfer accuracy of a two-stage leveling height difference.

The invention discloses a method and system for calibrating an accelerometer using a satellite-to-satellite tracking device. The method comprises the steps that original observation data on the satellite-to-satellite tracking device is acquired; coordinate transformation is performed on the original observation data to obtain observation data after the coordinate transformation; a gravity gradientcalculated value is calculated and obtained according to the observation data after the coordinate transformation and a gravity gradient observation equation; deviation calculation is performed on the gravity gradient calculated value and an actual gravity gradient observation value to obtain a deviation value; and the actual gravity gradient observation value is calibrated according to the deviation value. The method and system adopt the satellite-to-satellite tracking device to acquire the observation value, and calculate and obtain the gravity gradient calculated value, thereby effectivelysolving the problem that data generated simply by a gravity field model cannot meet better precision requirements, solving the problems such as terrain constraints, and achieving the purpose of high-precision calibration of the gravity accelerometer.

The invention discloses a method and device for determining seal level elevation, in particular relates to a method and device for determining seal level elevation by extracting GPS (Global Position System) signal gravity frequency shift. In the method, gravity frequency shift can be extracted based on GPS observation data (obs documents and sp3 documents) provided by an IGS (International GNSS (Global Navigation Satellite System) Service), and the gravity potential and the elevation of a single station are further determined based on gravity frequency shift signals. In addition, by means of a gravity field model, a theoretical value of the gravity frequency shift can be calculated and the effectiveness of the extracted gravity frequency shift signals can be verified. Accordingly, the invention has the following advantages: 1, because leveling measurement between two points with longer distance can be carried out without uninterrupted transmission by a plurality (or multiple) intermediate instrument stations, manpower and material resources are saved, a measurement period is short and the measurement is precise; 2, the measurement on a seal level elevation difference can be carried out between two points in a mountainous area or a place with higher near-distance elevation difference; and 3, a globally unified elevation datum can be realized.

The invention belongs to the field of gravity measurement, specifically discloses a strapdown gravimeter horizontal component measurement error correction method through utilization of an earth gravity field model and aims at eliminating a low frequency error in a gravimeter measurement result horizontal component. The low frequency error results from an attitude error. The method comprises the steps of (1), preprocessing original data of a strapdown airborne gravimeter; (2), processing the original data of a GNSS to obtain carrier position, speed and acceleration information; (3), carrying out combined Kalman filtering on the strapdown gravimeter and the GNSS to obtain specific force; (4), computing difference between a specific force result and carrier acceleration of the GNSS to obtaina gravity vector estimated result; (5), carrying out lowpass filtering on the gravity vector result to eliminate a high frequency noise; and (6), carrying out highpass filtering on the gravity vectorresult to eliminate a low frequency part comprising the attitude error and replacing the low frequency part through utilization of a computing result of the earth gravity field model, thereby obtaining a horizontal component estimated result in which the attitude error is eliminated. The method is characterized by good theoretical basis, high operability and simple realization.