JP2013213726A - Corner reflector group and decoy system including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decoy system capable of reducing locations and angles in which radio waves are not substantially reflected according to the locations or angles of corner reflectors.SOLUTION: A corner reflector group comprises: a plurality of corner reflectors 1 each of which has three radio wave reflecting films orthogonal to one another, and eight reflection areas 1c surrounded by three radio wave reflection films 1a. The plurality of corner reflectors 1 are serially concatenated on a same straight line, have same attitude to the straight line and have an intersection where the three radio wave reflection films 1a intersect. In each corner reflector 1, the same attitude is so configured that the straight line is located on one radio wave reflection film 1a, and the other two radio wave reflection films 1a have an angle of 45 degrees with respect to the straight line.

Description

  The present invention relates to a corner reflector group for deceiving enemies by reflecting radio waves and a decoy system including the corner reflector group.

A corner reflector generally used as a radar target is described in, for example, Patent Document 1 and has the configuration shown in FIG. As shown in FIG. 1, the corner reflector includes three radio wave reflection films 31 that are orthogonal to each other. As a result, regardless of the angle at which the radio wave enters the corner reflector, it can be reflected by the corner reflector in the direction in which the radio wave has entered.
For example, as shown in FIG. 2, both the radio wave A and the radio wave B can be reflected in the incident direction by the radio wave reflection films 31 orthogonal to each other.

  The corner reflector is emitted from a flying object, a ship, the ground, etc., and then expands into the shape of FIG. 1 in the air or on the water. For this purpose, the corner reflector includes a balloon 33, as in the example of FIG. The balloon 33 becomes spherical when inflated. Due to this expansion, each radio wave reflecting film 31 is attached to the inside of the balloon 33 so as to expand as shown in FIG. In the example of FIG. 1, the cylinder 35 inflates the balloon into a spherical shape by supplying gas into the balloon 33.

  With the configuration described above, for example, when a radio wave is incident on a corner reflector deployed in the air from a tracking radar device or a radar seeker of a missile, the corner reflector reflects in the direction in which the radio wave is incident as shown in FIG. Can do. As a result, the corner reflector can be used as a decoy for the radar.

  In addition, there exists the following patent document 2 as another prior art document of this application.

JP-A-4-355388 JP-A-9-190585

  In the corner reflector as described in the above patent document, it is possible to deceive the radar seeker by radio wave reflection. In general, a corner reflector has good reflection characteristics over a wide angle, but the magnitude of radio wave reflection varies depending on the position and angle of the corner reflector with respect to the radar seeker. Therefore, depending on the angle of the corner reflector, radio wave reflection may not be performed sufficiently.

  Therefore, an object of the present invention is to provide a corner reflector group capable of reducing the angle at which radio wave reflection cannot be sufficiently performed, and a decoy system including the corner reflector group, depending on the angle of the corner reflector.

In order to achieve the above object, according to the present invention, the present invention includes a plurality of corner reflectors having three radio wave reflection films orthogonal to each other and eight reflection regions surrounded by the three radio wave reflection films,
The plurality of corner reflectors are connected in series on the same straight line, have the same posture with respect to the straight line, and have intersections where the three radio wave reflection films intersect,
The same posture is characterized in that, for each corner reflector, the straight line is positioned on one radio wave reflection film, and the other two radio wave reflection films have an angle of 45 degrees with respect to the straight line. A group of reflectors is provided.

  According to an embodiment of the present invention, in the plurality of corner reflectors, at least one corner reflector is 40 degrees or more and 60 degrees or less or 120 degrees or more and 140 degrees or less around the straight line with respect to any other corner reflector. With a swivel angle difference of

According to an embodiment of the present invention, the corner reflector has a balloon that expands with gas pressure when gas is supplied to the inside,
The three radio wave reflection films are attached to the inner wall of the balloon and are orthogonal to each other when the balloon is inflated.

According to another embodiment of the present invention, the corner reflector includes three annular balloons that are inflated by a gas pressure and become annular when a gas is supplied to the inside,
Each of the three radio wave reflecting films is attached to the three annular balloons so that the outer peripheral edge portion is developed on a plane including the annular shape,
The three annular balloons are provided so as to be orthogonal to each other when inflated.

Moreover, according to the present invention, a launch pad installed on the ground or a ship,
A flying object for storing the corner reflector group;
A parachute for delaying the fall of the corner reflector group,
The flying object is launched from a launch pad toward a predetermined airspace, and expands the corner reflector group at a predetermined time,
A decoy system is provided in which the corner reflector group is dropped together with the parachute after the deployment.

According to the present invention, the plurality of corner reflectors are connected in series on the same straight line, have the same posture with respect to the straight line, and have intersections where the three radio wave reflection films intersect,
The same posture is such that, for each corner reflector, the straight line is positioned on one radio wave reflecting film and the other two radio wave reflecting films have an angle of 45 degrees with respect to the straight line. Angles with weak radio wave reflection can be compensated for each other, and as a whole corner reflector group, angles with low radio wave reflection can be reduced.

The block diagram of the corner reflector in a prior art is shown. It is a figure explaining the effect | action of the corner reflector in a prior art. It is a figure of the corner reflector in 1st Example of this invention. It is a figure of the decoy system in 1st Example of this invention. It is a figure of the corner reflector group in 1st Example of this invention. It is explanatory drawing of the centerline in this invention. It is a figure of the state to which the electromagnetic wave was directed from the radar seeker with respect to the corner reflector in this invention. It is a graph about the angle characteristic of the corner reflector of this invention. It is a graph of the angle characteristic of the corner reflector group which consists of two corner reflectors which made the turning angle difference 56 degree | times in this invention. It is a graph of an angle characteristic about the minimum value of the magnitude | size of reflection in the corner reflector group which consists of two corner reflectors of this invention. It is a figure of the corner reflector in 2nd Example of this invention. It is a figure of the corner reflector group in 2nd Example of this invention.

  A preferred embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 3 is a diagram of a corner reflector in the first embodiment of the present invention, and FIG. 4 is a diagram of a decoy system in the first embodiment of the present invention.
In this figure, 1 is a corner reflector, 1a is a radio wave reflecting film, 1b is a balloon, 1c is a reflection area, 2 is a moving device, 3 is a flying object, 4 is a parachute, 5 is a decoy system, 6a is a launch pad, and 6b is The ships 10 are a corner reflector group.

  In this example, the corner reflector 1 is inflated by gas pressure and has a balloon 1b and three radio wave reflection films 1a orthogonal to each other at the center, and the radio wave reflection film 1a can deceive a radar seeker. It is supposed to be able to In addition, since the three radio wave reflection films 1a are orthogonal and integrated, the structure has eight reflection regions 1c.

The corner reflector 1 may be configured without the balloon 1b.
The radio wave reflecting film 1a is not limited to a circular shape, and may be, for example, a triangle, a rhombus, or an ellipse.

The decoy system 5 in this embodiment expands the corner reflector group 10 including a plurality of corner reflectors 1 from the flying object 3 launched by the moving device 2. Until this corner reflector group 10 falls on the sea, it is possible to deceive an enemy or the like.
It is assumed that the corner reflector group 10 is automatically deployed after a predetermined time has elapsed from the launch or when a predetermined altitude is reached. On the other hand, for example, a configuration having a receiving device (not shown) for receiving a signal regarding the deployment timing from the ship 6b or the like and deploying at the timing when such a signal is received may be used.
In addition, the corner reflector group 10 drops after opening the connected parachute 4 after the expansion. By having this parachute 4, it is possible to spend a certain amount of time for the fall.

  In this example, the moving device 2 is a ship 6b provided with a launch pad 6a for launching the flying object 3, but may be a vehicle or the like on land.

  In this example, the corner reflector group 10 includes three corner reflectors 1 connected in series on the same straight line (on a turning shaft 14 described later). Each corner reflector 1 is connected in a form having a predetermined turning angle difference in order to reduce the angle at which the effect of radio wave reflection is weakened.

  Each corner reflector 1 may be configured to have a gas cylinder (not shown) for injecting gas into the respective balloon 1b, or the balloon 1b of the corner reflector 1 connected from the beginning may be partly. It may be configured to be manufactured in a connected state, and gas may be injected into the balloon 1b by one gas cylinder. In addition, by installing a gas cylinder at the connecting portion of the parachute 4 and the uppermost corner reflector 1 or at the bottom of the lowermost corner reflector 1 to function as an appropriate weight, the corner reflector group 10 can have a stable shape. The structure which can assist dropping is sufficient.

FIG. 5 is a diagram of a corner reflector group in the first embodiment of the present invention, and FIG. 6 is an explanatory diagram of a center line.
FIG. 7 is an explanatory diagram of a state in which radio waves are directed from the radar seeker to the corner reflector, and FIG. 8 is a graph of the angular characteristics of the corner reflector.
In this figure, 11a to 11c are three circular wave reflecting films orthogonal to each other, 11d is a reflection region, 12 is a radio wave, 13 is a turning direction when turning the corner reflector 1, 14 is a turning axis, and 15 is A center line, 16 represents a reference line.
FIG. 7A shows a state in which a radio wave 12 from a radar seeker (not shown) is directed perpendicular to the radio wave reflection film 11a. 7B is a configuration diagram of the radio wave reflection films 11a to 11c viewed from the radar seeker side in the state of FIG. 7A, and FIGS. 7C and 7D are FIGS. It is a block diagram of the radio wave reflection films 11a to 11c as viewed from the radar seeker side when turning 45 degrees and 90 degrees respectively in the turning direction 13 around the turning axis 14 from the state of A).

In this example, as shown in FIG. 5, each corner reflector 1 in the corner reflector group 10 is connected on a turning shaft 14. Further, it is fixed with respect to the turning shaft 14 with the same posture and the same turning angle difference.
Here, this “same posture” means that, for each corner reflector, the turning shaft 14 is positioned on one of the radio wave reflection films, and the other two radio wave reflection films are 45 to the rotation axis 14. It is desirable that the angle has a degree angle. As shown in FIGS. 6 (A) to 6 (C), for each of the eight reflection regions 11d of the corner reflector 1, an axis existing at an equiangular α from each of the radio wave reflection films 11a to 11c forming the reflection region 11d. Is the center line 15, four of the eight center lines are oriented in the horizontal direction. For this reason, it can be expected to exhibit a high radio wave reflection effect on a radar seeker or the like that is a deception target. The angle α in FIGS. 6A to 6C is a reference line 16 that is a straight line connecting the leg of the perpendicular line extending from the center line 15 to the electric field reflection films 11 a to 11 c and the center of the corner reflector 1. The angle between the line 16 and the center line 15 is obtained.
Further, the “same turning angle difference” means, for example, the second turning angle difference when the turning angle difference about the turning shaft 14 in the second corner reflector with the turning shaft 14 as the rotation axis is 30 °. When the corner reflector is used as a reference, the turning angle difference of the third corner reflector is also set to 30 °.
In addition, it is preferable that each corner reflector 1 is connected so that the turning shaft 14 passes through the intersection of the three radio wave reflection films 11a to 11c in each corner reflector 1.

  In FIG. 5, the turning direction 13 is clockwise, but it may be turned counterclockwise.

FIG. 8 shows the relationship between the turning angle and the magnitude of radio wave reflection when the corner reflector 1 is turned in the turning direction 13 from the state of FIG. In this figure, the horizontal axis represents the turning angle of the corner reflector 1, and the vertical axis represents the magnitude of reflection with respect to the radar.
Here, regarding the magnitude of reflection, the value of RCS (Radar Cross Section: radar reflection cross section [m ² ]) is represented by the common logarithm [dBm ² ].
In this example, as shown in FIG. 8, the maximum value of the magnitude of reflection when one corner reflector is used will be described as 20 [dBm ² ] for convenience.

  In FIG. 8, when the turning angle is around 0 degrees, 90 degrees, and 180 degrees, there is a temporary strong radio wave reflection, but except this part, the curve shape has a maximum point around 50 degrees and around 130 degrees. It has become. Therefore, from this figure, the corner reflector 1 can perform relatively strong radio wave reflection when the turning angle is in the vicinity of 35 to 80 degrees and 100 to 145 degrees. On the other hand, in the vicinity of 2 degrees to 10 degrees and in the vicinity of 170 degrees to 178 degrees, the radio wave reflection is very weak.

  In the following, based on FIG. 8 described above, a turning angle difference to be set in the corner reflector group 10 having two or more corner reflectors 1 will be considered.

FIG. 9 is a graph when the turning angle difference is 56 degrees in the corner reflector group including the two corner reflectors A and B.
According to this graph, the minimum values are around 80 degrees and around 160 degrees (the magnitude of reflection is about 17 [dBm ² ]), and at what angle compared to the case where there is one corner reflector shown in FIG. Even if it exists, the magnitude | size of reflection stable to some extent is maintained.

That is, as shown in FIG. 9, in the case of a corner reflector group including a plurality of corner reflectors including two corner reflectors having a turning angle difference of 56 degrees, the magnitude of reflection in the entire corner reflector group is at least about 17 [dBm ^2. ] Can be secured.

FIG. 10 shows a result obtained by turning the turning angle difference from 0 degree to 180 degrees and obtaining the minimum value for each turning angle difference as in the case where the turning angle difference is 56 degrees.
In this figure, for example, when the minimum required reflection size of the entire corner reflector group is about 15 [dBm ² ], the range of the turning angle difference exceeding this is between 40 degrees and 60 degrees, and It is between 120 and 140 degrees.
That is, in the case of three or more corner reflector groups having two corner reflectors having a turning angle difference in the above range, at least the magnitude of the reflection in the entire corner reflector group regardless of the number of connected corner reflectors. This means that about 15 [dBm ² ] can be secured.

For example, a ring-shaped balloon as shown in FIG. 11 can be used even if the balloon is not a balloon having three radio wave reflecting films inside, like the corner reflector in the first embodiment described above. It is.
When compared with the balloon in the first embodiment, the annular balloon has a merit that it can be rapidly inflated because the gas injection region is small.
In FIG. 11, 21 is a corner reflector, 21a is a radio wave reflecting film, and 21b is an annular balloon.

  In this embodiment, the corner reflector 21 includes three radio wave reflecting films 21a and three annular balloons 21b. Each of the radio wave reflecting films 21a has an outer peripheral edge attached to the annular balloon 21b so as to expand on a plane including the annular balloon 21b.

In this example, the radio wave reflecting film 21a is formed of a fabric using conductive fibers.
The conductive fiber may be, for example, a nylon fiber coated with a metal film (copper, silver, etc.).
In this example, the radio wave reflecting film 21a is composed of three circular films, and has a structure in which the planes are assembled orthogonal to each other during the expansion. Preferably, the radio wave reflection film 21a is formed so that the strings that bisect each film are orthogonal to each other. With this structure, when the annular balloon 21b is inflated, eight sets of three radio wave reflection films 21a orthogonal to each other are provided as one set.
When a gas is supplied to the inside of the annular body balloon 21b, the annular body balloon 21b is expanded by a gas pressure and becomes annular.
By using the annular balloon 21b, for example, the corner reflector 21 can be inflated with a gas amount much smaller than that of a spherical balloon.
Therefore, there is an advantage that the time required for the expansion of the corner reflector 21 can be shortened.
The annular balloon 21b may be formed of a plastic film such as polyolefin or polyvinyl chloride.

  Preferably, it is desirable to prevent the annular balloon 21b from expanding beyond a predetermined limit volume by wrapping the outer periphery of the annular balloon 21b with a restraining cloth.

By using the corner reflector 21 shown in FIG. 11 in place of the corner reflector 1 shown in FIG. 3, for example, the time required for inflation of the balloon and the amount of gas required for inflation can be reduced, so that the speed can be increased. In addition, the corner reflector 21 can be expanded.
Further, for example, the space for storing the corner reflector 21 can be reduced.

FIG. 12 is a configuration diagram when the corner reflector group 30 using the corner reflector 21 described in FIG. 11 falls.
In this case as well, as in the case of FIG. 3 described above, the corner reflectors 21 of the corner reflector group 30 are connected in a form having a predetermined turning angle difference in order to reduce the angle at which the effect of radio wave reflection is weakened.

The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.
The corner reflector of the present invention may be used for purposes other than deceiving enemies and the like. For example, you may use the corner reflector of this invention in order to notify a victim's whereabouts like patent document 2. FIG.

1 corner reflector, 1a radio wave reflecting film, 1b balloon,
1c reflection area, 2 moving device, 3 flying object, 4 parachute,
5 Decoy system, 6a launch pad, 6b warship,
10 Corner reflector group,
11a to 11c radio wave reflection film,
12 radio waves, 13 turning direction, 14 turning axis,
15 center line, 16 reference line,
21 corner reflector, 21a radio wave reflecting film,
21b Annular balloon, 24 parachute,
30 Corner reflectors

Claims (5)

A plurality of corner reflectors having three radio wave reflection films orthogonal to each other and eight reflection regions surrounded by the three radio wave reflection films,
The plurality of corner reflectors are connected in series on the same straight line, have the same posture with respect to the straight line, and have intersections where the three radio wave reflection films intersect,
The same posture is characterized in that, for each corner reflector, the straight line is positioned on one radio wave reflection film, and the other two radio wave reflection films have an angle of 45 degrees with respect to the straight line. Reflector group.   In the plurality of corner reflectors, at least one corner reflector has a turning angle difference of 40 degrees or more and 60 degrees or less or 120 degrees or more and 140 degrees or less around the straight line with respect to any other corner reflector. The corner reflector group according to claim 1, wherein: The corner reflector has a balloon that expands by gas pressure when gas is supplied to the inside,
The corner reflector group according to claim 2, wherein the three radio wave reflection films are attached to an inner wall of the balloon and are orthogonal to each other when the balloon is inflated. The corner reflector has three annular balloons that are inflated by gas pressure when gas is supplied to the interior,
Each of the three radio wave reflecting films is attached to the three annular balloons so that the outer peripheral edge portion is developed on a plane including the annular shape,
The corner reflector group according to claim 2, wherein the three annular balloons are provided so as to be orthogonal to each other when inflated. A decoy system comprising the corner reflector group according to any one of claims 1 to 4,
A launch pad installed on the ground or in a ship;
A flying object for storing the corner reflector group;
A parachute for delaying the fall of the corner reflector group,
The flying object is launched from a launch pad toward a predetermined airspace, and expands the corner reflector group at a predetermined time,
The corner reflector group falls after the deployment with the parachute.

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