RU2645743C1 - Method for searching for submerged objects - Google Patents

Abstract

FIELD: radio engineering and communication.

SUBSTANCE: invention relates to radio positioning and can be used to determine the coordinates of submerged objects (aircraft, ships, etc.). Technical result is achieved due to the fact that the method comprises preliminary installation of N ≥ 1 containers on the object planned for crossing the water surface, in each container, a reflector of electromagnetic waves (EMW) is laid with the possibility of its automatic undocking when the object is immersed in an aqueous medium, the undocked reflector is self-torn and floats to the water surface, the reflector is made in the form of a network structure, in the nodes of which there are metallized elements with positive buoyancy. Search aircraft with a radar station installed on it is sent to the area of the proposed immersion of the object, which irradiates the water surface and fixes the coordinates of the submerged object according to signals scattered by the EMW reflector.

EFFECT: achieved technical result is reduced time and material costs for searching for a submerged object and increased accuracy of determining its coordinates.

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Description

The invention relates to the field of radar and can be used to determine the coordinates of sunken objects (aircraft, aircraft, underwater or surface ships), which as a result of an accident plunged into the aquatic environment.

Known methods for detecting objects emanating under water.

The known method is similar to the detection of an object located in the thickness of the bottom soil according to patent RU No. 2280266, publ. 07/20/2006, bull. No. 20 G01S 15/04 (2006.01), provides for the following actions:

from the carrier of sonar equipment (NGA), equipped with a transceiving antenna of a side-scan sonar, they emit a signal, receive a reflected signal, measure the propagation time of the signal and calculate the distance to the object, move the NGA above the bottom relative to the proposed object with the simultaneous emission of an acoustic signal, receive reflected from the object signal and recalculate the distance to the object.

The disadvantage of this analogue is the low search efficiency that occurs in case of uncertainty about the possible location of an object.

A known method of detecting objects under water according to patent RU No. 2424542, publ. 07/20/2011, bull. No. 32, IPC G02B 27/00 (2006.01).

The analogue method includes the following actions: stereoscopic images of the controlled water space are recorded directly in the aquatic environment and analyzed; stereoscopic images from several spaced points are simultaneously recorded; analyze all images; Foreign objects are determined by their shadows from light sources.

The disadvantage of this analogue is the limited scope, limited only by small immersion depths of the detected object.

The closest in technical essence to the claimed is a method for detecting underwater objects according to patent RU No. 2495448, publ. 10/10/2013, bull. No. 28 IPC G01S 5/02, G01S 15/06 (2010.01).

The prototype method includes the following actions: at a given point in the ocean, ships are placed from the side of which emit a sound wave, irradiated certain sections of the surface wave with an electromagnetic signal from the board of the first group of aircraft, receive reflected signals from the second group of aircraft, measure the Doppler shift of the received signals using which determine the coordinates of the underwater object.

The disadvantages of the prototype are:

high material costs associated with the need to use the ship, a large number of aircraft and the organization of the search;

low accuracy of determining the coordinates of the object even with slight waves of the surface of the body of water due to the destruction of the wave diffraction grating on the surface of the body of water, on the basis of which a method for calculating the coordinates of the object is implemented;

the search is possible only at a previously known location of the underwater object to which the ship must be directed, the transition of which, taking into account large areas of the sea or ocean, requires up to several days;

the method is practically not applicable when finding the object at many kilometers depths.

The aim of the invention is to develop a method for searching for sunken objects (ships, aircraft, etc.), providing a reduction in material and time costs for its implementation, improving the accuracy of determining the coordinates of the object.

This goal is achieved by the fact that in the known method of searching for sunken objects, which consists in the fact that from the board of a search aircraft (PLA) that emits a signal, a signal reflected from the water surface is received and its coordinates are fixed, and the electromagnetic signal is emitted and received in the claimed method ( EMC) using an airborne radar station (radar) submarine.

Preliminarily, N≥1 containers are installed on the body of the object planned for crossing the water surface. In each of the containers, a reflector of electromagnetic waves (EMW) is laid in a folded state with the possibility of its automatic detaching from when an object is immersed in an aqueous medium. The computer reflector is made with positive buoyancy. Upon detection of the fact that the object is lost, the submarine is sent to the alleged area of the water surface, the water surface is irradiated with the help of the onboard radar. When receiving the signal scattered by the reflector of the electromagnetic field, its coordinates are fixed, indicating the location of the sunken object.

The EMV reflector is made in the form of a self-expanding mesh structure, in the nodes of which metallized elements with positive buoyancy are fixed. As elements using metallized granules from a material with a density that ensures their positive buoyancy.

At a given altitude H flight of the PLA, the effective scattering area is chosen from the condition [1, p. 357]:

и

- соответственно мощность на выходе передатчика и на входе приемника РЛС; G - коэффициент усиления приемо-передающей антенны РЛС; λ - длина рабочей волны РЛС.Where

and

- respectively, the power at the output of the transmitter and at the input of the radar receiver; G is the gain of the radar transceiver antenna; λ is the radar operating wavelength.

The listed new set of essential features provides automatic marking of the area of the water surface where the object was immersed in the water column. Search in this area does not require large material and time costs, because relatively easy to detect using radar submarine due to the emergence on the water surface of an effective reflector EMW. Marked indicates the possibility of achieving the specified technical result when using the claimed invention.

The claimed method is illustrated by drawings, which show:

in FIG. 1 - types of objects to be searched in the aquatic environment: a) a submarine; b) an airplane;

in FIG. 2 - reflector EMV in the form of a mesh structure: a) in a folded state; b) in the expanded;

in FIG. 3 is a drawing explaining a process for implementing the method;

in FIG. 4 - reflected signals on the radar indicator.

Implement this method as follows.

Preliminarily, on object 1 (see Fig. 1): a ship, a submarine, an aircraft (aircraft, helicopter, drones, etc.), planned to cross the water surface (sea, ocean, etc.), set N ≥1 containers 2 (see Fig. 2a) in selected, taking into account design restrictions, places 3 of object 1 (Fig. 1).

Containers 2 are installed with the possibility of their automatic detaching from the body of object 1 using, for example, pressure sensors that generate a control signal to the actuator for undocking (not shown in Fig. 1) container 2. Container 2, once in an aqueous medium, releases it reflector 4 EMV. For this, the container 2 can be made in the form of a tube, which is soaking in water, thereby freeing up the rolled-up reflector 4 of the EMW.

In each container 2, the EMV reflector 4 is installed in a folded state, made with positive buoyancy.

At the intersection of the water surface, object 1, for example, an airplane (see Fig. 3) can, as a result of a technical malfunction, plunge into the water environment 15. Containers 2 are automatically undocked from the body of the object 1 when it enters the water 2. In the water environment 15, each container 2 releases the reflector 4 EMW, which self-rotates and floats to the water surface 14 (Fig. 3), taking the form of a rectangle (square or other shape) with dimensions A × B (Fig. 2).

The reflector 4 EMW is made in the form of a mesh structure with cells Δ, in the nodes of which are fixed metallized elements 5 (see Fig. 2b) with positive buoyancy. Elements 5 are made in the form of granules from a material with a density that ensures their positive buoyancy, followed by their metallization.

The manufacturing technology of ultralight metallized granules is known and described, for example, in RF patent No. 2413039 of 02.27.2011.

To ensure self-expansion of the EMF reflector 4 in its mesh structure (see Fig. 2b), springy threads 6 are installed along the perimeter, vertical and horizontal axes of symmetry, which ensures the preservation of the shape of the EMF reflector 4 in the unfolded state even when the water surface is noticeable.

The remaining mesh structure of the EMF reflector 4 is made, for example, of heavy-duty polyethylene or Kevlar filaments 7, with a cross-sectional diameter in the range of (0.02-0.1) mm, which can also be metallized, to increase reflectivity. The mesh size Δ of the mesh structure is selected from the condition Δ≤ (0.05-0.1) λ, where λ is the working wavelength of the radar 8 on board the search and aircraft 9 (see Fig. 3). With such cell sizes, the reflectivity of the mesh structure is close to the reflectivity of a continuous metal plate [2, p. 168-172].

Given that at 80% of the time, the wave height on the surface of the seas and oceans does not exceed 3.5 m [1, p. 323], the effective scattering area of EMF reflectors 4 remains virtually unchanged.

When contact with object 1 is lost or an alarm signal is received from it, a search aircraft (PLA) 9, equipped with an onboard radar 8, flies out with the help of which the signal is emitted and the signal reflected from the water surface is flown to the area of possible immersion of object 1.

If there is no EMW reflector 4 in the area of the irradiated water surface, on the radar screen 10 11 (see Fig. 4), in addition to the probe pulse 12, there is only a noise background of fluctuating signals reflected from irregularities in the water surface.

When the radar 8 of the reflectors 4 EMV gets on the screen 11 of the radar 8 against the background of fluctuating noise, pulses of the reflected signals 13 from the reflectors 4 EMV emerge on the water surface 14.

On the PLA 9, the coordinates of the EMF reflectors 4 located on the water surface are fixed, which coincide with the coordinates of the passing PLA 9 at the time of the appearance on the radar screen 10 of the 10 pulses of the reflected signals 13.

Then, a group of technical equipment for search and rescue operations is sent to the detection area of reflectors 4 EMW.

Under the influence of wind and / or surface currents, EMF reflectors 4 can move from their ascent.

Therefore, depending on the time elapsed from the moment of loss of contact with object 1 to the moment of detection of surfaced reflectors 4 EME, it is necessary to increase the radius of search and rescue operations. In any case, the total time of the approximate determination of the coordinates of the sunken object 1 will be significantly less due to the detection of surfaced reflectors 4 EMW.

When the flight height N is selected for the PLA 9, the necessary value of the effective scattering area σ of the EMF reflector 4 is calculated from the condition of ensuring the stability of the pulse of the reflected signal 13 on the screen 11 of the airborne radar 10 according to formula (1) or experimentally. The technique of experimental measurement of σ is known and described in [1, p. 359-374].

Thus, in the inventive method, thanks to the new combination of essential features, the relatively small area within which the object is located is quickly located in the aquatic environment 15 on the bottom surface 10 and then its exact location is established by a relatively small group of forces and technical means, which reduces the time and material costs for determining the coordinates of an object under water, i.e. A formulated technical result is achieved when using the claimed technical solution.

Literature

1. Reference radar. Under. ed. M. Skolnik. New York. 1970.V. 1. - M .: Sov. radio.

2. Antennas. Part I, ed. Muravyova Yu.K. - L .: YOU, 1963.

Claims (3)

1. The method of searching for sunken objects, which consists in the fact that they emit a signal from the board of a search aircraft (PLA), receive a signal reflected from the water surface and fix its coordinates, characterized in that they emit and receive an electromagnetic signal using an airborne radar station ) A submarine, preliminary on an object planned to cross the water surface, install N≥1 containers, in each of which the reflector of electromagnetic waves (EMW) is laid in a folded state with the possibility of it automatic undocking from the object when the object is immersed in the aquatic environment, and the EMV reflector with an effective scattering area σ is made with positive buoyancy, a signal is received from the EMR reflector from the EMV reflector that has surfaced on the water surface and coordinates are recorded indicating the location of the object under water moreover, at a given altitude H of the PLA flight, the effective dispersion area σ of the EMF reflector is chosen from the condition: σ = (4π) ³ H ⁴ (P _CRD / R _CRM ) G ² λ ² , where R _CRM and R _CRM are the output power, respectively transmitter and power of the reflected signal at the input of the radar receiver; G is the gain of the radar transceiver antenna; λ is the radar operating wavelength. 2. The method according to p. 1, characterized in that the reflector EMV is made in the form of a self-expanding mesh structure, in the nodes of which are fixed metallized elements with positive buoyancy. 3. The method according to p. 2, characterized in that as the metallized elements use metallized granules from a material with a density that ensures their positive buoyancy.

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