SU434354A1 - METHOD OF ISOLATION OF LOCAL MAGNETIC ANOMALIES - Google Patents

Description

one

The invention relates to the field of aeromagnetic methods of prospecting and exploration of minerals.

A known method for isolating local magnetic anomalies of small extent and intensity, for example, anomalies caused by dykes or mud volcanoes. In this method, along with aeromagnetic measurements on the profile, measurements are made at the point of observation of variations using a magnetic variation station (MVO). When processing information, the MVC readings are subtracted from the magnetometer readings.

The state of the art permits the transmission of an MFR signal over the radio path and the introduction of corrections due to variations directly during the aeromagnetic survey.

With this method of eliminating false signals from geomagnetic variations, the real possibility of registering false anomalies due to the inequality of variations at their observation point and on the survey profile is preserved.

The proposed method of isolating local magnetic anomalies is aimed at reducing the likelihood of registering spurious signals from variations, taking into account their possible divergence at the MBC location and profile.

This goal is achieved due to the fact that simultaneously with the measurements on the profile, the correlation coefficient of the signal of the magnetometer with the signal of variations and

exclude as false those anomalies whose level of correlation with variations exceeds a specified value.

The drawing shows a block diagram of a device allowing the proposed method to be implemented.

The output of the magnetometer 1 operating in the characteristic frequency band for the anomalies allocated is connected via delay line 2 and key 3 to recorder 4. At the same time, the output of magnetometer 1 is connected to one of the inputs of the correlation circuit 5, to the other input of which the output of the receiving device 6 signals AIM The input of the correlation circuit is connected to the control input

key 3.

The principle of the device is as follows.

Signals of magnetometer 1 after a delay in delay line 2 through unlocked key 3 are sent to recorder 4. In the case of a correlation of a signal of a magnetometer with an MBC signal at the output of the receiving device 6, the output of the correlation circuit 5 generates a signal that, when the preset value is exceeded

level locks key 3. At the same time the signal

The magnetometer 1 does not arrive at the recorder 4.

Thus, for the rejection of spurious signals, the criterion of their correlation with the MBC signals is used.

In the known method of subtracting variations, the possibility of registering false anomalies due to the uncompleted part of the variations remains. The latter is caused by the fact that variations on the survey profile and at the location of the AIM are not identical. The proposed method significantly reduces the probability of registering false signals, since it allows them to be completely rejected on the basis of the level of correlation with the MBC signal.

Subject invention

A method of isolating local magnetic anomalies during aeromagnetic survey, which consists in simultaneously measuring geomagnetic variations and transmitting them over a communication channel, characterized in that, in order to reduce the likelihood of detecting false anomalies due to geomagnetic variations, simultaneously with the measurement of the magnetic field, the correlation the signal coefficient of the magnetometer and the signal of variations exclude the signals characterizing those a-nomals, the level of correlation with variations exceeds the specified value.