SU792194A1 - Apparatus for eliminating geomagnetic field variation of aeromagnetometer readings - Google Patents

Description

The invention relates to magnetometry, and can be used in aeromagnetic surveys to search for 'minerals.

It is known that during aeromagnetic surveying of the terrain, it is necessary to exclude variations in the geomagnetic field [1].

For this, simultaneously with the aeromagnetic survey, the increments of the magnetic field at a given point are measured and a correction is introduced into the readings of the aeromagnetometer.

A device is known for eliminating geomagnetic field variations from the readings of an aeromagnetometer, in which 15 readings of a magnetosensitive sensor (MHD) of magnetic field increments are recorded by a recorder and transmitted through a telemetry unit to an aeromagnetometer for automatically entering corrections [2j.

The closest technical solution to the invention is a device for eliminating variations in the geomagnetic field from the readings of an aeromagnetometer 25, containing the magnetic field increment of magnetic field increments and a recorder. The disadvantages of the known device include the inability to exclude the influence of local interference on the readings of the MRI 30 increments of the magnetic field distorting the magnetogram when entering corrections [3].

Such interference includes: interference caused by the movement of all types of vehicles, pedestrians, with metal objects, local consumers of electricity, etc. These interference are local in nature and do not affect the readings of the aeromagnetometer, at the same time they significantly distort the magnetic field measured by the TCD increments of the magnetic field and thereby distort the results of aeromagnetic surveys when entering corrections.

The aim of the invention is to increase aeromagnetic imaging by reducing the influence of local magnetic interference.

This goal is achieved by the fact that in the device containing the magnetic field increment magnetic field and the recorder, at least one additional magnetic field increment magnetic field, a subtraction circuit, two high-pass filters, two delay lines, a logic unit and a switch are introduced, and the outputs of the main and additional The MCD are connected to the inputs of the subtraction circuit, to the inputs of the high-pass filters, through lines, delays - to the first and second inputs of the recorder and through a switch, the control input of which is connected to the logic output one unit, - a third output recorder, a logic block input connected to the output of the subtractor circuit, and the other two inputs connected to the outputs of high pass filters.

The drawing shows a functional diagram of the proposed device.

The device contains the magnetic field density increments of the magnetic field 1 and 2, the outputs of which are connected to the inputs of the subtraction circuit 3, as well as to the inputs of the high-pass filters 4 and 5. The output of the subtraction circuit 3 and also the output of the high-pass filters 4 and 5 are connected to the inputs of logic block b. The outputs of the TCD 1 and 2 are also connected to the inputs of the delay lines 7 and 8, the outputs of which are connected to two inputs of the switch 9 and to two inputs of the recording device. 10. The output of the logical block b is connected to the third, control, input of the switch 9. The output of the switch 9 is connected to the third input of the recording device.

Magnetosensitive sensors

1,2 are located at a distance exceeding the length of the magnetic field of the sources of local interference, which for the above local interference is the first hundreds of meters.

The device operates as follows: if a local interference signal arrives, for example, at the MFR, a signal appears at the output of the subtraction circuit 3 and at the output of the high-pass filter 4. At the same time, a signal controlling switch 9 will appear at the output of logic circuit 6, which will switch to the third the input of the recording device 10; the output of the TCD 2 through the delay line 8.

If the interference comes to the TCD 2, then the TCD 1 will be connected to the third input of the recording device 10.

Thanks to the proposed device in subsequent introduction of corrections in aeromagnitometry readings, carried out during the post-processing or during the shooting with the use of the telemetry link excluded variation, measured only in MCHD, which is currently the least affected by local noise GOVERNMENTAL ^7. .Ύ-.

Claims (1)

inputs of the subtraction circuit, with inputs of high-pass filters, through delay lines — with the first and second inputs of the recorder and through a switch, the control of which input is connected to the output of the logic unit — to the third output of the recorder, one input of the logical unit, connected to the output of the subtraction circuit, and the other two inputs are connected to the high-pass filter outputs. The drawing shows a functional diagram of the proposed device. The device contains an MHD increment of the magnetic field 1 and 2, the outputs of which are connected to the inputs of subtraction circuit 3, as well as with the inputs of high-pass filters 4 and 5. The output of the subtraction circuit 3 and the outputs of high-pass filters 4 and 5 are connected to the inputs of logic block b . The outputs of the MHP 1 and 2 are also connected to the inputs of the delay lines 7 and 8, the outputs of which are connected to the two inputs of the switch 9 and to the two inputs of the registering device .10. To the third, control to the memory, the input of the switch 9 is connected to the output of the logic block b. The output of switch 9 is connected to the third input of the recording instrument. Magnetosensitive sensors 1,2 are located at a distance greater than the magnetic field of sources of local interference, which for the above local interference is the first hundreds of meters. The device works as follows: if a local interference signal arrives, for example, at an MHD, then The output of the subtracting circuit 3 and the output of the high-pass filter 4. At the output of the logic circuit b, a signal is obtained that controls switch 9, which switches the output of the MHD 2 to the third input of the recording device 10 through the delay line 8. If the interference arrives at the MHE 2, then the MHD 1 will be connected to the third input of the recording device 10. Thanks to the proposed device, the subsequent correction of the aero-magnetometer readings, carried out during telemetry channel, the variations that are measured only by the TOR, which is the least affected by local interference, are excluded. . Apparatus of the Invention A device for eliminating geomagnetic field variations from the aeromagnitometer readings, comprising an MRT magnetically sensitive magnetic field increment sensor and a recorder, characterized in that, in order to improve the accuracy of aeromagnetic survey by reducing the influence of local magnetic interference, at least one is entered into it. n ,, an additional MDB, a subtraction circuit, two high-pass filters, two delay lines, a logic unit and a switch, the outputs of the main and additional MDC are connected to the inputs subtraction circuits, with inputs of high-pass filters and through delay lines with the first and second inputs of the recorder and through a switch, the control input of which is connected to the output of the logic unit, with the third input of the recorder, one input of the logic unit connected to the output of the subtraction circuit, and two The other inputs are connected to the high-pass filter outputs. Sources of information taken into account in the examination 1. Instructions on magnetic reconnaissance. M., Gosgirltehizdat, 1963. 2.patent.US 3274488, cl. 324-43 publ. 1966. 3. Magnetovariatsionnaya station MVS sb. Geophysical instrumentation, 1973, no. 53, p.3.4 prototype.