A computer-implemented method includes: receipt and accession of magnetic field data from a constellation of satellites providing global coverage over the Earth in a time span less than one day; inter-calibrating the magnetic field data from all satellites to a common standard; quantifying the global magnetic disturbance and selecting quiescent intervals at least as short as one day for evaluation of Earth's internally-generated field; calculating global maps of the mean vector magnetic field for each quiet interval from the average of all satellite measurements in angular bins; converting the time sequence of global maps of the mean fields to time series of angular harmonic coefficients via direct convolution; applying spectral and regression analysis to the harmonic coefficient time series to identify and remove artifacts in the signals; reconstructing a continuous time and spatial representation of the magnetic field continuous in time and angular position globally.

A computer-implemented method includes: receipt and accession of magnetic field data from a constellation of satellites providing global coverage over the Earth in a time span less than one day; inter-calibrating the magnetic field data from all satellites to a common standard; quantifying the global magnetic disturbance and selecting quiescent intervals at least as short as one day for evaluation of Earth's internally-generated field; calculating global maps of the mean vector magnetic field for each quiet interval from the average of all satellite measurements in angular bins; converting the time sequence of global maps of the mean fields to time series of angular harmonic coefficients via direct convolution; applying spectral and regression analysis to the harmonic coefficient time series to identify and remove artifacts in the signals; reconstructing a continuous time and spatial representation of the magnetic field continuous in time and angular position globally.

The present disclosure discloses a magnetic compensation method for performance quality assessment by using an aeromagnetic compensation error model, comprising: acquiring an upper limit of an error of a magnetic noise by using the aeromagnetic compensation error model, before an aeromagnetic flight, wherein the magnetic noise is caused by both an environmental background field in an exploration area and an aeromagnetic flight platform; determining, according to the upper limit of the error of the magnetic noise, whether the environmental background field and the aeromagnetic flight platform are suitable for an aeromagnetic survey flight, and if so, performing a calibration flight to acquire a compensation coefficient; and acquiring data of an attitude term by performing an actual flight, calculating an interference magnetic field by the data of the attitude term and the compensation coefficient acquired during the calibration flight, and performing magnetic compensation.

The present disclosure discloses a magnetic compensation method for performance quality assessment by using an aeromagnetic compensation error model, comprising: acquiring an upper limit of an error of a magnetic noise by using the aeromagnetic compensation error model, before an aeromagnetic flight, wherein the magnetic noise is caused by both an environmental background field in an exploration area and an aeromagnetic flight platform; determining, according to the upper limit of the error of the magnetic noise, whether the environmental background field and the aeromagnetic flight platform are suitable for an aeromagnetic survey flight, and if so, performing a calibration flight to acquire a compensation coefficient; and acquiring data of an attitude term by performing an actual flight, calculating an interference magnetic field by the data of the attitude term and the compensation coefficient acquired during the calibration flight, and performing magnetic compensation.

Disclosed is a magnetotelluric measurement system, comprising: a magnetic sensor probe for collecting an electromagnetic signal as an impulse response of an earth and transmitting the same to a signal readout circuit; the signal readout circuit configured for receiving and amplifying the electromagnetic signal collected by the magnetic sensor probe; a data acquisition and processing module configured for receiving and processing electromagnetic signal amplified by the signal readout circuit; a storage module configured for storing the electromagnetic signals amplified by the signal readout circuit and processed by the data acquisition and processing module; a first casing for enclosing the magnetic sensor probe and the signal readout circuit; and a second casing for enclosing the data acquisition and processing module and the storage module. The disclosure realizes the detection of low-noise wide-frequency band magnetic field signal, and solves problems involving deep detection of the mineral resources in complex areas.

Disclosed is a magnetotelluric measurement system, comprising: a magnetic sensor probe for collecting an electromagnetic signal as an impulse response of an earth and transmitting the same to a signal readout circuit; the signal readout circuit configured for receiving and amplifying the electromagnetic signal collected by the magnetic sensor probe; a data acquisition and processing module configured for receiving and processing electromagnetic signal amplified by the signal readout circuit; a storage module configured for storing the electromagnetic signals amplified by the signal readout circuit and processed by the data acquisition and processing module; a first casing for enclosing the magnetic sensor probe and the signal readout circuit; and a second casing for enclosing the data acquisition and processing module and the storage module. The disclosure realizes the detection of low-noise wide-frequency band magnetic field signal, and solves problems involving deep detection of the mineral resources in complex areas.

A transmitter loop is carried by a first aircraft. A receiver sensor is carried by a second aircraft. The first aircraft and the second aircraft fly away from each other. The transmitter loop transmits a primary magnetic field. The transmitted primary magnetic field induces a current in the earth. The induced current generates a secondary magnetic field in the air. The receiver sensor receives the generated secondary magnetic field, and detects strength of the received secondary magnetic field.

A transmitter loop is carried by a first aircraft. A receiver sensor is carried by a second aircraft. The first aircraft and the second aircraft fly away from each other. The transmitter loop transmits a primary magnetic field. The transmitted primary magnetic field induces a current in the earth. The induced current generates a secondary magnetic field in the air. The receiver sensor receives the generated secondary magnetic field, and detects strength of the received secondary magnetic field.

An improved in-field referencing 1 (IFR1) technique is provided, wherein a single mid-lateral well measurement of local magnetic field is used. In one aspect of directional drilling, a single set of IFR values for a planned well is obtained. The single set of IFR values is captured at a single location in a mid-lateral section of the planned well. A global magnetic model corresponding to the Earth's magnetic field is obtained. An improved magnetic model is generated by correcting the global magnetic model for local anomalies using the single set of IFR values.

An improved in-field referencing 1 (IFR1) technique is provided, wherein a single mid-lateral well measurement of local magnetic field is used. In one aspect of directional drilling, a single set of IFR values for a planned well is obtained. The single set of IFR values is captured at a single location in a mid-lateral section of the planned well. A global magnetic model corresponding to the Earth's magnetic field is obtained. An improved magnetic model is generated by correcting the global magnetic model for local anomalies using the single set of IFR values.