41 results about "Magnetic dip" patented technology

A high-accuracy geomagnetic vector measurement method is characterized in that a vertical additional magnetic field and a horizontal additional magnetic field which have the same intensity but different directions are added to the position of a probe of a high-accuracy total-field magnetometer; a geomagnetic field without additional magnetic fields and a resultant magnetic field with an additional forward magnetic field and an additional reversed magnetic field are measured respectively; and then, each component, including a vertical component Z, a horizontal component H, a geomagnetic inclination I and a declination D, of a geomagnetic vector can be computed, and the method is suitable for fast and high-accuracy geomagnetic vector measurement outdoors or in a fixed station. According to the method, the geomagnetic vector measuring accuracy is in positive correlation with the accuracy of the matched magnetometer, and the high-accuracy total-field magnetometer is superior to a fluxgate three-component magnetometer with 10 nT of measuring errors. A high-accuracy geomagnetic vector field measurement device comprises one group or two groups of field coils and a tripod, the field coils are added to the outside of the high-accuracy total-field magnetometer probe, and the field measurement device is matched with the high-accuracy total-field magnetometer and used for rapidly measuring each component of the geomagnetic vector outdoors or in the fixed station.

Methods for improving wellbore survey accuracy and placement are disclosed. The Earth's magnetic field may be measured at a magnetically clean surface location and correlated with a non-magnetic reference direction to obtain a direction of the Earth's field (e.g., a magnetic declination or a magnetic inclination). The direction of the Earth's magnetic field may in turn be processed in combination with magnetic measurements made in a subterranean borehole to obtain one or more survey parameters.

The invention discloses a carrier attitude and heading calculation method assisted by a geomagnetic field model and a system. The method comprises the following steps that an ideal magnetic inclination angle is calculated according to position information of a carrier and the geomagnetic field model; an estimated magnetic inclination angle is calculated according to an output value of an accelerometer and an output value of a magnetic sensor; whether environmental magnetic interference exists or not is judged according to the ideal magnetic inclination angle and the estimated magnetic inclination angle; if the environmental magnetic interference exists, an equivalent weight matrix of magnetic sensor measurement values is constructed according to self-adaptive weights of the magnetic sensor measurement values; carrier attitude information and heading information are calculated according to an accelerometer measurement value, the magnetic sensor measurement values and the equivalent weight matrix of the magnetic sensor measurement values. According to the carrier attitude and heading calculation method assisted by the geomagnetic field model and the system, the environmental magnetic interference is detected according to the ideal magnetic inclination angle and the estimated magnetic inclination angle, when the environmental magnetic interference is detected, the equivalent weight matrix of the magnetic sensor measurement values is constructed, self-adaptive adjustment of contribution of the magnetic sensor measurement values to a state estimation value is achieved, and the calculated attitude information and heading information have robustness.

The invention discloses a simple geomagnetic vector measurement method, which is used for solving the technical problem that the existing geomagnetic vector measurement method is poor in measurement accuracy. The technical scheme is as follows: the method comprises the following steps of: measuring geomagnetic vector information of a spatial point by using a magnetometer; carrying out error analysis and correction on the geomagnetic vector information measured by the magnetometer by using an error compensation model; and converting the geomagnetic vector obtained after correction into a geographic coordinate system through a coordinate conversion method so as to finally obtain the relatively accurate geomagnetic vector information of a measurement point. When the total magnetic field intensity H is equal to 51,800nT and a magnetic dip alpha is equal to 48 degrees, an error between a celestial magnetic field component obtained through geomagnetic vector measurement at the measurement point and a theoretical celestial magnetic field component is effectively controlled within 50nT.

The invention discloses a method for simply measuring an orthogonal angle of a component quadrature coil in a vector magnetic meter. The method comprises the steps that by installing a scalar magnetometer probe on a support inside a magnetic dip coil, after two high-stability constant-current sources are connected with the magnetic dip coil and a magnetic declination coil respectively, the high-stability constant-current sources are utilized for applying currents which are equal in size and same or opposite in direction on the magnetic dip coil and the magnetic declination coil, and then the currents which are equal in size and same or opposite in direction are applied on the magnetic dip coil and the magnetic declination coil simultaneously in sequence, resultant magnetic fields under various conditions are determined separately, and then the orthogonal angle of the component quadrature coil is worked out. In the process, precise mechanical axial alignment operation is not needed, the error brought by inconsistency of assembling is eliminated, the orthogonal angle of a two-dimensional or three-dimensional coil can be measured efficiently and accurately, and scientific research or production use is convenient.

The invention discloses a roll angle detection method of a directional firework shell and a detection device thereof. The method comprises the steps of: firstly, determining and inputting related information of emitting the firework shell during detection; computing a local magnetic inclination and a local magnetic declination; computing a relatively top reference angle and an initiation phase; fixing the initiation phase to the firework shell, loading the firework shell and emitting; beginning to work by a shell-borne part after emitting the firework shell; detecting a geomagnetic signal by a magnetic detection circuit; computing the phase of the geomagnetic signal; finally computing the deviation of the initiation azimuth; and continuously outputting deviation signals to an attitude control device. When the deviation of the azimuth is 0, the initiation azimuth is needed. The detection device comprises a ground part and the shell-borne part. The detection method can be used for directly detecting the deviation of the initiation azimuth without integral or accumulated errors. The detection device has small volume, simple circuit, low cost and strong impact resistant performance.

A small magnetic compass capable of suppressing the effects from the magnetic dip is provided. The magnetic compass includes a substrate 11, a two-axis sensor 12 arranged on the substrate 11, for detecting external magnetic fields, a magnetic north calculating device 13 for detecting an azimuth from outputs of the respective magnetic sensors, a rotating magnetic field generating device 14 for generating a rotating magnetic field on the plane of the substrate using a reference point P1 as a center of rotation.

The invention provides an upper continuation and lower continuation method for a multilayer equivalent source of magnetic survey data. The method comprises the steps of S1, inputting magnetic field data, and establishing a topographic relief curved surface according to topographic height information of an area where a relief observation curved surface is located; S2, determining a spatial range ofmesh generation, performing continuous structured non-uniform mesh generation, and further determining an inversion model solving space; S3, according to the magnetic inclination angle, the magneticdeclination angle and the magnetic induction intensity of the geomagnetic field, performing integral equation three-dimensional inversion calculation with a depth regularization factor, a positive value constraint term and a regularization term on the magnetic field data based on an inversion model solving space to obtain a multi-layer equivalent source model of a magnetic anomalous body; and S4,performing magnetic field forward modeling calculation based on an integral equation by utilizing the multilayer equivalent source model to obtain magnetic field data after upper continuation and/or lower continuation generated by the magnetic anomalous body. The method has the beneficial effects that the required upper continuation or lower continuation data can be adaptively, quickly, efficiently and accurately generated for the magnetic anomalous body.

The invention provides an omnidirectional helium optical pumping magnetic force instrument. The omnidirectional helium optical pumping magnetic force instrument is composed of a magnetic sensor and a magnetic force instrument host. The magnetic sensor is composed of a high-frequency high-pressure excitation system, an orthogonal helium lamp chamber pumping system and a helium absorption chamber magnetic field system. The magnetic sensor and the tracking type magnetic force instrument host are integrated together so as to overcome the problem of a dead zone of a helium optical pumping magnetic sensor, and it is unnecessary to adopt an orthogonal multi-magnetic sensor and a complex servo system for overcoming the dead zone. The omnidirectional helium optical pumping magnetic force instrument can provide a high-efficiency rapid approach for earth magnetic field investigation and magnetic anomaly detection under different magnetic dip angles at global high and low latitudes.

The magnetic north detecting device comprises: a 3-dimensional geomagnetism sensor unit including three geomagnetism sensors for detecting respective components of a geomagnetism magnetic field intensity in respective directions of three coordinate axes perpendicular to each other; and a 3-dimensional operation functional section for carrying out an operation on the basis of the components of the geomagnetism magnetic field intensity detected by the geomagnetism sensors, and calculating a magnetic north direction of the geomagnetism, and the 3-dimensional operation functional section carries out the operation and calculates the magnetic north direction of the geomagnetism, based on two assumptions that: (i) at least one axis of three coordinate axes of the 3-dimensional geomagnetism sensor unit is level to the earth surface; and (ii) an angle of a geomagnetism magnetic field vector which is calculated from the detected components of the geomagnetism magnetic field intensity, referring to the earth surface, coincides with a dip angle of the geomagnetism which is assumed beforehand.

The invention provides a PDE-based magnetic measurement data equivalent source upper continuation and lower continuation method, which comprises the steps of S1, obtaining magnetic field data d0, andestablishing a topographic relief curved surface according to topographic height information of an area where the magnetic field data is located; s2, determining a spatial range of mesh generation, and performing non-uniform multilayer mesh generation; s3, according to the magnetic inclination angle, the magnetic declination angle and the magnetic induction intensity of the geomagnetic field, carrying out PDE three-dimensional inversion calculation with a depth regularization factor, a positive value constraint term and a regularization term on the magnetic field data d0 to obtain a multi-layer equivalent source model of the magnetic anomalous body; and S4, performing PDE-based magnetic field forward modeling calculation by using the multilayer equivalent source model to obtain upper continuation and/or lower continuation magnetic field data generated by the magnetic anomalous body. The invention has the beneficial effect that self-adaptive and high-precision upper continuation or lower continuation can be carried out on underground magnetic anomaly data in a complex environment.

An improved total field calibration system and method is disclosed for reducing the rotational misalignment between magnetic and gravity sensors in a directional sensing system. The effect of variation of surface components of the Earth's magnetic field during the calibration process on magnetometer misalignment may be completely eliminated by requiring the magnetic dip derived from the sensing system to match that of the Earth's field obtained from a reference source. The calibration process can be performed without monitoring the declination change during the calibration process. Directional sensing systems can be calibrated accurately during a period when the Earth's magnetic field changes rapidly.

The invention discloses a method and a system for resolving a roll angle of a rotating aircraft. A dynamic equation set around the center of mass of the aircraft is established as a driving equation, a relation equation between a geomagnetic azimuth angle and a pitch angle, a yaw angle, a magnetic declination angle, a magnetic dip angle and a course angle is taken as an observation equation, and an actual measured value of the geomagnetic azimuth angle is taken as an observed quantity; a pitch angle and a yaw angle are estimated through extended Kalman filtering; a geomagnetic vector reference angle is resolved; and finally, a high-precision roll angle is calculated. According to the method and the system for resolving the roll angle of the rotating aircraft, the resolving precision of the roll angle is improved.

The invention discloses a method and system for automatically acquiring a magnetic dip and a magnetic declination. The method is characterized in that by pre-storing the magnetic dip and magnetic declination data information of different regions around the world, matching characteristics of the GPS latitude and longitude information and the magnetic dip and magnetic declination data information are utilized to obtain accurate magnetic dip and magnetic declination data of a region where a device is operated, so the system automatically retrieves the appropriate and accurate magnetic dip and magnetic declination data according to the GPS latitude and longitude, efficiency of system operation is greatly improved, and thereby accurate positioning of an electronic compass in the case of no dataservices is realized.

The invention belongs to the field of petroleum drilling engineering, in particular to a method for calculating the surface angle of a gravity tool of an inclinometer while drilling based on a small-range MEMS acceleration sensor. Firstly, the sensitivity of MEMS accelerometer and fluxgate is less than 1mg and 5nT respectively at room temperature. The sensitivity of MEMS accelerometer and fluxgateis less than 5nT. Acquired data on well deviation (INC), azimuth (Az) and magnetic dip (Lambda) under static conditions are preserved; the mathematic model of sensor orthogonal calibration is established. The values of acceleration sensor and fluxgate component are calculated according to the traditional algorithm and the algorithm provided in step c, and stored in two arrays. The results show that the acceleration sensor and the fluxgate component are in good agreement with each other. After several fixed time periods, the standard deviation of the data in the two arrays is calculated respectively, and the data at the end of the arrays with relatively small standard deviation is selected as the real calculation value of the gravity tool face angle. The invention greatly improves the application range of the small-range MEMS acceleration sensor and reduces the cost of the MWD system.

The invention provides a forward and reverse modeling method for magnetic measurement data under a demagnetization effect based on an integral equation, and the method comprises the following steps: determining a space range of mesh generation according to an underground target region, and carrying out the mesh generation of the space range through an orthogonal mesh; setting a magnetic inclination angle, a magnetic declination angle and magnetic induction intensity of a geomagnetic field; setting an observation position, and obtaining magnetic measurement data at the observation position under the consideration of the demagnetization effect by utilizing a magnetic measurement data forward modeling calculation method under the demagnetization effect based on an integral equation; and inputting magnetic field observation data, carrying out model optimization calculation through a magnetic survey data inversion method based on an integral equation under a demagnetization effect in combination with a regularization item, and carrying out inversion calculation on an underground target to obtain an inversion result. According to the method, the magnetic measurement data forward modeling under the condition of considering the demagnetization effect can be calculated, and the inversion under the condition of considering the demagnetization effect can be carried out according to the magnetic measurement data.

The invention discloses a dual-magnetic coordinate inversion positioning method and device. The method comprises the following steps of acquiring the total intensity F and a magnetic dip angle I of a geomagnetic field at a current position; calculating the geographic latitude and longitude of the current position corresponding to the total intensity F and the magnetic dip angle I of the geomagnetic field by using a nonlinear relation model; and judging whether a target position is reached or not according to the difference value between the geographic longitude and latitude of the current position and the geographic longitude and latitude of the target position. By establishing the nonlinear mapping relation between the geomagnetic coordinates and the longitudes and latitudes, the geographic longitudes and latitudes of the position can be obtained only by measuring the total magnetic field intensity and the magnetic dip angle of the position, and the very good practicability and product portability are achieved.

The invention relates to the technical field of inspection unmanned aerial vehicle line inspection simulation, and discloses a power transmission line inspection unmanned aerial vehicle simulation system magnetic field environment correction method, which comprises the following steps: extracting position information of a power transmission line inspection unmanned aerial vehicle; calculating geomagnetic latitude; calculating geomagnetic field intensity; calculating a magnetic dip angle and a magnetic declination angle; calculating a three-dimensional component of the geomagnetic field intensity; calculating the magnetic induction intensity around each phase of line; calculating a comprehensive magnetic field generated by the power transmission line at the inspection unmanned aerial vehicle target point; calculating a comprehensive magnetic field of the inspection unmanned aerial vehicle target point.