JPH0444239B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an underwater magnetic exploration device for exploring magnetic abnormalities existing on the ocean floor.

Magnetic detectors have traditionally been used to search for magnetically abnormal objects buried under the sea. However, in the conventional method of using a magnetic detector, the magnetic detector is attached to a pedestal-like structure, and the structure is suspended from the measurement vessel to near the ocean floor by operating levers, etc. With the above limit, the search width is
Within 10m, the depth that can be explored is at most 15m to 20m
was the limit. Also, due to the use of a frame-like structure, the towing speed could not be increased very much. Therefore, it has been nearly impossible to accurately survey a wide area of water in a short time, regardless of its depth.

It is an object of the present invention to provide an underwater magnetic surveying device that eliminates the drawbacks of the conventional devices and is capable of surveying a wide area at high speed and with high precision regardless of the depth.

In order to achieve the above objects, the underwater magnetic detection device of the present invention includes a magnetic detector towed by a towing vessel for detecting an abnormal magnetic object, and a magnetic detector towed together with the magnetic detector, which is towed by a towing ship and disconnects when the abnormal magnetic object is detected. A marking device that is separated and emits a constant signal, a sonar that is attached to the float towed by the towing vessel and that detects the position and depth of the magnetic detector, and a sonar that detects the position and depth of the magnetic detector from the sonar. a position detection circuit for detecting a position, a circuit for receiving a magnetic signal from the magnetic detector and discriminating the presence or absence of an abnormal magnetic object, a circuit section for controlling the target device to be separated by detecting the abnormal magnetic object, and the above-mentioned The system includes a target storage circuit that receives a position signal from a position detection circuit and stores the separated position of the target aircraft, and a control device that is mounted on a towing vessel.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a magnetic detector, which is towed far away from the hull of a towing boat 3 through a towing cable 2 under the sea. 4 is a target device and magnetic detector 1
However, when an abnormal magnetic object is detected, it is separated from the magnetic detector 1 on the spot, and a pin is projected from the built-in sounding body. Power is supplied to the magnetic detector 1 and the marking device 4 from the towing vessel 3 via a power cable built into the towing cable 2. Reference numeral 5 denotes an acoustic sonar, which is attached to a float 6 and towed by a sonar towing cable 7. The acoustic sonar 5 is located on the water surface almost above the magnetic detector 11, and transmits sound waves to accurately detect the position and depth of the magnetic detector 1, which is towed by a tidal current different from the surface current. A magnetic signal from the magnetic detector 1 and a signal indicating the position and depth of the magnetic detector 1 from the acoustic sonar 5 are sent to a control device 8 mounted on the towing vessel 3. The towing boat 3 constantly measures the position of the float 6 to reduce errors in the exploration position.

FIG. 2 is a circuit block diagram of the embodiment shown in FIG. 1, including the constituent circuits of the control device 8. The magnetic signal from the magnetic detector 1 is applied to a filter circuit 11, which removes noise caused by towing vibration of the magnetic detector 1, etc., and the magnetic signal from which the noise has been removed is applied to a signal calculation and discrimination circuit 12. Also, since a signal indicating the depth and position of the magnetic detector 1 is applied from the acoustic sonar 5 to the depth/azimuth detection circuit 13, the signal calculation/discrimination circuit 12 takes into consideration the depth and position signals from the depth/azimuth detection circuit 13. Then, it is determined whether the magnetic signal is above a predetermined level. Even if the magnetic signal has a certain level, a metal object as small as an empty can will not exceed a predetermined level and will not be considered an abnormal magnetic object. If an abnormal magnetic object is detected, the signal calculation discrimination circuit 12
sends a signal to the marking device 4, stores the position of the point in the target storage circuit 14, and disconnects the marking device 4 from the magnetic detector 1, and after a certain period of time, the marking device 4 projects a pin using a sounding body. Furthermore, the control device 8
Detector position indicator 15, magnetic signal indicator 16,
The detector position display 15 receives a signal from the depth direction detection circuit 13 and displays the depth and position of the magnetic detector 1, and the magnetic signal display 16 displays the magnetic detector 1, The magnetic signal obtained by changing every moment through the filter circuit 11 and the signal calculation circuit 12 is displayed, and the target display 17 detects an abnormal magnetic object and displays the position of the position set on the object. Although not shown in the figure, the control device 8 is equipped with a recording device that plots the amount of magnetic signals on a track map along with the towing. No. is also recorded.

When searching for abnormal magnetic objects underwater using the above-mentioned underwater magnetic survey device, a towing boat 3 is floated in the sea area to be surveyed as shown in FIG. Tow aircraft 4. When an abnormal magnetic object exists on the seabed, the magnetic detector 1 detects it, and the signal processing circuit 12 outputs a discrimination signal, so the marking device 4 is separated and the sounding body of the marking device outputs a sounding signal. Emitted. In addition, the control device 8 of the towing vessel 3 records the point where the marking device 4 is set. Therefore, the anomalous magnetic object recovery vessel easily recovers the anomalous magnetic object by referring to the location information of the target point communicated from the towing vessel 3 and searching for the sound signal from the target device 4. be able to.

In the above embodiment, instead of one magnetic detector being towed by the towing cable 2, a plurality of magnetic detectors are deployed at predetermined intervals on the deployable cable in a horizontally deployable manner, thereby allowing exploration of a wide area of water. becomes possible.

As described above, according to the underwater magnetic exploration device of the present invention, since the magnetic detector is towed by a towing cable, exploration is possible at high speed and even at deep depths, and the towing cable allows for exploration to be carried out even at great depths. Since the magnetic detectors are located far apart, there is no magnetic noise from the towing vessel. Furthermore, when the signal calculation and discrimination circuit derives a discrimination output for the abnormal magnetic object, the target device connected to the magnetic detector is disconnected, and the target device located at the abnormal magnetic object is controlled to emit a signal and its position is determined. Since the magnetic object is memorized, the recovery ship can track not only the position information of the abnormal magnetic object but also the transmitted signal, which has the advantage of improving the efficiency of recovery work by divers and the like.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a circuit block diagram of the embodiment shown in FIG. 1, including the constituent circuits of a control device. 1: Magnetic detector, 2: Towing cable, 3: Towing boat, 4: Marker, 5: Acoustic sonar, 6: Float,
7: Sona towing cable, 8: Control equipment, 11:
Filter circuit, 12: Signal calculation discrimination circuit, 13:
Depth orientation detection circuit, 14: Target storage circuit, 15:
Detector position indicator, 16: Magnetic signal indicator, 1
7: Target indicator.

Claims (1)

[Scope of Claims] 1. A magnetic detector towed by a towing vessel that detects an abnormal magnetic object; A target aircraft that is towed together with the magnetic detector and is separated upon detection of an abnormal magnetic object and emits a certain signal. , a sonar that is attached to a float towed by the towing vessel and detects the position and depth of the magnetic detector; a position detection circuit that detects the position and depth of the magnetic detector from the sonar; and the magnetic detector. a circuit that receives a magnetic signal from the sensor and determines the presence or absence of an abnormal magnetic object; a circuit that controls the target device to be separated upon detection of the abnormal magnetic object; and a circuit that receives a position signal from the position detection circuit. An underwater magnetic exploration device comprising: a control device mounted on a towing vessel and comprising a target storage circuit for storing the separated position of the target vehicle.