SU883814A1 - Magnetometer - Google Patents

Description

I

This invention relates to magnetometric means, namely to towed magnets: meters, and can be used to produce detailed marine magnetic surveys.

Known are BST magnetometers containing a magnetically sensitive element, an amplifier, a recorder, and a power supply unit 1.

In well-known mast-meters, the magnetically sensitive element is towed to a distance S equal to 2-5 lengths of the towing vehicle in order to eliminate the influence on the measurement results of the magnetic field of the towing vehicle.

Since the length of the towing vehicle, such as a hydrographic vessel, reaches 100 m, the value of S may be 500 m.

In order to conduct a detailed magnetic survey in order to search for ferromagnetic objects located at the bottom, and to solve other special problems, the location of the measurement results must be tied to the location with an accuracy not exceeding a unit of meters.

This requires the location of the magnetically sensitive element to be determined with an error not exceeding a few meters.

In the process of magnetic survey, depending on the magnitude of the towing speed, as well as under the influence of hydrometeorological factors. tori (waves, currents, etc.) the coordinates (X, Y, 2) of the magnetically sensitive element with respect to the towing vehicle vary considerably.

Known towed magnetometers do not produce information that can determine the coordinates of a magnetosensitive

10 elements in relation to the towing vehicle.

Thus, a detailed magnetic survey with the required accuracy using known towed magnetometers is not possible.

15

The aim of the invention is to improve accuracy.

The goal is achieved by the fact that a magnetometer containing a magnetically sensitive element connected in series and

Claims (3)

20 amplifier, recorder, provided with a source with a scanning magnetic field connected to its input, a control unit, a demodulator, a computing unit, the first input of which is connected to the output of the demodulator, inputs connected to the amplifier and the control unit, the second input of the computing unit is connected with the control unit, and the output of the computing unit is connected to the input of the recorder. At the same time, the source with the scanning magnetic field is implemented in the form of three solenoids located along the coordinate axes, or in the form of a constant source of a magnetic field attached to a platform rotating with the help of a propulsion device. FIG. 1 shows a functional diagram of the magnetometer; in fig. 2 and 3 - a source with a scanning magnetic field. The towed magnetometer (Fig. 1) contains a magnetically sensitive element 1 connected with a cable 2 to the input of amplifier 3, the output of which is connected to the input of demodulator 4. The output of demodulator 4 is connected to the input of computing unit 5. The output of computing unit 5 is connected To the input of the recorder 6. A source 7 with a scanning magnetic field is connected through the control unit 8 to the power supply unit 9. In addition, the control unit 8 is connected to the demodulator 4 and the computing unit Source 7 with a scanning magnetic field (Fig. 2) consists of three solenoids 10 located along the coordinate axes. Solenoids 10 are connected via the control unit 8 to the power supply 9. In block 8 of the junction in series, current-controlled elements 11, such as variables, varying the current, are connected to the solenoids 10. controlled resistance. Source 7 with a scanning magnetic field (Fig. 3), made in the form of a permanent magnet 12, mounted in. cardan suspension 13 with two degrees of freedom, on the axes 14 of which electric motors 15 are installed, connected via control unit 8 to power supply unit 9. The magnetometer works as follows. In the process of towing the magnetically sensitive element 1 on the towing vehicle with the help of the control unit 8, the power supply unit 9 is connected to the source 7 and the operating mode of the source 7 is set. In the magnetic sensitive element 1, an electrical signal is generated by the total magnetic field, which goes to the amplifier 2 3. Then the amplified signal enters demodulator 4, where the separation of the signals of the Earth’s magnetic field and the field of the source 7 4 occurs on the basis of their different frequency characteristics. Next, the selected signal enters the computational unit 5, where, according to a given algorithm, the desired coordinates of the magnetometric element 1 are determined, the value of which is stored on the recorder 6, the accuracy of determining the coordinates of the magnetometric element 1 can be calculated {by the formulas ATM ATM iftvfi ,. AH - 1 fAM (fj g 5, - The accuracy of determining the direction of the magnetic moment of the source 7 in the ship’s coordinate system; Atf - The error of determining the angle between the magnetic moment of the source 7 and the distance vector P from source 7 to the magnetometric element I; knowledge of the magnitude of the magnetic moment of the source M (t) 7; -the relative uncertainty of separating the signal of source 7 from the total signal; - the relative instrumental error of measuring the magnitude modulus of the vector of intensity T; The distance from the source 7 to the magnetometric element 1 can be calculated by the following formula: 0.8 Y and the sensitivity of the magnetometer. In the case when M (t) -, l-5 MO) I & tL- Aba.-10, .. , - tv f in mea, and UChNT),, u (NT), then 410.; . D / D ISO5 Therefore, the distance to the towed magnetically sensitive element with a towing distance of 300 m will be determined with an error of ± 0.3 m, and the direction to it will be with an error of 30, Thus, the towed magnetometer will detect the position of the magnetically sensitive element relative to the speed bar with the required for producing detailed magnetic accuracy surveys. In addition, the towed magnetometer will allow to determine the position of one object relative to another with increased accuracy. Claims of an inventive micrometer, comprising sequentially connecting a shensh.1e magnetically sensitive element and an amplifier, recorder, characterized in that it is equipped with a source with a scanning magnetic field connected to its input by a control unit, demodulator, computing unit, the first input of which is connected to the output of the demodulator, the inputs connected to the amplifier and the control unit, the second input of the computing unit is connected to the control unit, and the output of the output unit is connected to the input the registrar. 2. The magnetometer according to claim 1, which is based on the fact that the source is scanned by a scanning magnetic field, is made in the form of three solenands that are closed on the coordinate axes. 3. The Mapoggometer according to claim 1, which is also distinguished by the fact that the source with the magnetic field of the magnetic field is implemented as a permanent source of magnetic field attached to the rotating platform with the help of the propulsion device. Sources of information taken into account during the examination 1. Instructions for the operation of the MBM marine towed magnetometer. Publisher of the General Directorate of Navigation and Oceanography of the USSR Ministry of Defense, JL, 1977, p. 87