KR20150044447A - Device and method for blocking GPS jamming - Google Patents

Abstract

The present invention relates to a device and a method for blocking GPS jamming to reduce the impact of jamming and to improve the ability to continue an operation with the installation of a jamming barrier on the GPS antenna of a vessel.

Description

Background of the Invention Field of the Invention The present invention relates to a GPS jamming device,

The present invention relates to an apparatus and a method for blocking GPS (Global Positioning System) radio disturbance. The GPS radar disturbance blocking device and the blocking method according to the present invention can be applied to both military and civilian applications.

GPS is a satellite navigation system, not only for airplanes, ships and cars, but also for locating its own position by using satellites anywhere in the world. The position information can be precisely calculated according to the triangular method by measuring the precise time and distance from three or more satellites by using a GPS receiver. Currently, it is widely used to obtain distance and time information from three satellites and to correct the error with one satellite.

Unlike a compass, a satellite navigation system can acquire latitude, longitude and altitude as well as accurate time with three-dimensional velocity information. Position accuracy differs depending on military and civilian use. For civilian use, the horizontal and vertical errors are about 10 to 15 m, and the speed measurement accuracy is 3 cm per second. In addition, the satellite is equipped with three atomic clocks, providing time information with an error of only one second in 36,000 years.

Satellite-based navigation system GPS has been developed by the US Department of Defense, and consists of a ground control group that monitors and controls satellite groups and satellites, and a user group. The satellite group consists of 24 NAVSTAR (navigation satellite timing and ranging) satellites and is distributed as an atomic model in six circular orbits over 22,000 km of Earth.

GPS is currently being applied in a wide range of fields such as providing simple location information, automatic navigation and traffic control of airplanes, ships and automobiles, prevention of collision of oil tankers, precise surveying of large civil works, mapping, Have been developed in various ways.

On the other hand, enemy forces, imprudent forces, and competitors in the military and the private sector can hit GPS equipment through radio disturbances. For example, when the enemy's GPS radio disturbance is disturbed, the GPS equipment of the allied traps performing the mission within the influence range is disturbed, so that it is impossible for the allied trap to normally receive GPS information (time, location). As such, the enemy GPS radio disturbance affects the operation of the GPS and the many sensors, communication electronic equipment, and weapons systems that are in operation in the friendly traps.

It is an object of the present invention to provide an apparatus and method for blocking GPS propagation disturbance.

In order to achieve the above object, the present invention provides a GPS radio wave disturbance interception device, comprising: a metal shielding film installed to surround a GPS antenna; and the metal shielding film is grounded.

In the present invention, the metal shielding film blocks the GPS disturbance wave received by the horizontal wave, and GPS information is received from the GPS satellite by vertical waves.

In the present invention, it is preferable that the metal barrier layer has a semi-conical shape with a larger diameter and an open upper part.

In the present invention, the angle between the side surface and the horizontal plane of the metal barrier layer is preferably 50 to 70 degrees.

In the present invention, the metal barrier layer may be composed of one or more alloys selected from metals effective for reflecting electromagnetic waves such as aluminum, stainless steel, silver, copper, and chromium.

In the present invention, a radio wave reflecting coating layer or a radio wave absorbing coating layer may be formed on the surface of the metal barrier layer.

The GPS radar disturbance interrupter according to the present invention can be used for military or civil purposes, and can be applied to ships, for example.

According to another aspect of the present invention, there is provided a method of manufacturing a GPS antenna, including: installing a metal shielding film to surround a GPS antenna; And a step of grounding the metal shielding film.

According to the present invention, the influence of the radio disturbance can be reduced by providing the radio wave disturbance shielding film in the GPS antenna. Especially, by installing a radio disturbance shield on the GPS antenna of the ship, it can be operated as a countermeasure against enemy GPS disturbance attack, and the operation continuation ability can be improved.

1 is a block diagram of a GPS radar disturbance blocking device according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a GPS radar disturbance interrupter according to the present invention. The interrupter according to the present invention includes a radio disturbance shield 20 made of a metal and installed to surround the GPS antenna 10 have.

The GPS antenna 10 receives the position / time information 50 from the space GPS satellites 30 with a vertical wave and the disturbance wave 60 generated from the enemy GPS radio disturbance device 40 is a horizontal wave Lt; / RTI >

In the present invention, the vertical wave is interpreted to include radio waves inclined at ± 30 degrees with respect to the vertical line, including the vertical concept of the dictionary meaning.

Likewise, the horizontal wave in the present invention is interpreted to include a wave inclined at ± 30 degrees with respect to the horizontal line, including the horizontal concept of the dictionary meaning.

The metal shielding film 20 according to the present invention is characterized in that the GPS disturbance wave 60 received by the horizontal wave is blocked by reflection and absorption and the GPS satellite 30 receives the GPS information 50 by vertical waves .

Since the altitude (20,200 km) of the GPS satellites 30 is much higher than the altitude of the terrestrial or maritime disturbance device 40, the disturbance wave incident on the horizontal side is physically blocked and the vertically incident GPS satellite information is normally received It is possible. At this time, when GPS receives at least three GPS satellite information, GPS works normally.

As shown in the figure, it is preferable that the metal shielding film 20 has a semi-conical shape with a larger diameter and an open upper part. When viewed in cross section, it is an inverted trapezoid. Here, the semicircular cone may be a circular cone in which both the upper and lower portions are rounded in the vicinity of the vertex.

As described above, since the metal shield 20 is formed as a semi-cone shaped upside down, the GPS satellite 30 can receive the GPS information 50 more widely. Usually, seven to nine GPS satellites 30 are used, but at least four or more GPS satellites 30 must be within the effective range to receive the GPS information 50 smoothly. When the metal shielding film 20 is installed in an inverted semicircular shape, at least four or more GPS satellites 30 are within the effective range, so that the GPS information 50 can be smoothly received.

The side surface of the metal shielding film 20 forms a constant angle with the horizontal surface of the metal shielding film 20. The angle between the side surface of the metal shielding film 20 and the horizontal plane theta] is preferably 50 to 70 degrees, more preferably 55 to 65 degrees, and most preferably 60 degrees. If the angle is too large, that is, if the metal shielding film 20 comes close to the substantially cylindrical shape, reception of the GPS information 50 may not be smooth as described above. On the other hand, if the angle is too small, the GPS propagation disturbance blocking effect may deteriorate. As described above, the metal shielding film 20 is formed into a half-cone shape at an appropriate angle, so that more satellite signals can be received.

The height of the metal shield 20 may be 1.5 to 5 times, preferably 2 to 4 times the height of the GPS antenna 10.

The lower diameter of the metal shield 20 may be 1.5 to 5 times, preferably 2 to 4 times the width of the GPS antenna 10.

The diameter of the upper portion (open portion) of the metal shielding film 20 may be determined according to the lower diameter of the metal shielding film 20 and the angle? Between the side surface of the metal shielding film 20 and the horizontal plane.

The thickness of the metal barrier film 20 is not particularly limited, and a thickness sufficient to maintain appropriate rigidity is sufficient, for example, 0.1 to 10 mm, preferably 0.5 to 5 mm.

The material of the metal shielding film 20 is not particularly limited and may be made of a metal having a high conductivity. For example, the metal shielding film 20 may be made of a metal selected from metals effective for reflecting radio waves such as aluminum, stainless steel, silver, copper, Or a mixture of two or more kinds of alloys.

A radio wave reflecting coating layer or a radio wave absorbing coating layer may be formed on the surface of the metal shielding film 20 in order to further improve the radio wave disturbance blocking effect. The radio wave reflecting coating layer or the radio wave absorbing coating layer can be formed by coating the surface of the metal shielding film 20 with a radio wave reflecting paint or a radio wave absorbing paint. The electromagnetic wave absorbing coating material may be a material having a very high wave absorption rate, for example, a graphite powder made of a dielectric material mixed with foamed styrene resin or the like, and a magnetic material made of ferrite or the like. The radio wave absorbing coating layer may have a two-layer structure of an electrically conductive material and an absorbing layer composed of ferrite as a constituent component and a denatured layer containing ferrite. The two-layer structure has a much wider frequency band It can absorb radio waves. The paint must be thick and durable.

The metal shielding film 20 is grounded in order to block propagation disturbance. When the disturbance radio wave is incident on the metal shield 20, the earth is absorbed into the ground (the earth is a giant conductor) or another conductor having a large capacity, and the radio wave disturbance is blocked. In addition, since the GPS equipment is usually installed outside and is often exposed, the metal shielding film 20 should be grounded for the purpose of preventing an electric accident such as an electric shock. The grounding method is to connect the metal shielding film 20 and the ground to the earth by means of a conductor, that is, the grounding line 70 in FIG. 1, Or the like) and the metal barrier film 20 by a wire.

The GPS radar disturbance interrupter according to the present invention can be applied to both military and civilian applications, and can be applied to both the ground, sea and air, and is particularly applicable to traps.

According to another aspect of the present invention, there is provided a method of manufacturing a GPS antenna, including: installing a metal shielding film to surround a GPS antenna; And a step of grounding the metal shielding film.

According to the present invention, in order to block the GPS radio wave disturbance, a conical metal shielding film having an open top is formed around the GPS antenna to block horizontally disturbing radio waves, and information received vertically from GPS satellites can be normally received .

As a result of simulated disturbance propagation simulation test, it showed a blocking effect of more than 15 dB in GPS radio disturbance. The radio interference effect (improvement effect) of 15 dB of the radio disturbance (interference) signal according to the use of the metallic shielding device (radio wave shielding effect) is that the radio interference signal is smaller than that of the radio disturbance shield 15 dB lower.

Under the same conditions, the improvement of 10 dB of the radio interference signal means that the maximum attackable distance using the radio disturbance signal of the enemy group is reduced. That is, it is possible to shorten the enemy's range of disturbance attack of GPS radio waves. According to the present invention, there is an effect (for example, 200 km? 40 km) in which the enemy's GPS radio disturbance attackable distance is significantly reduced.

The installation cost of the metal shield is about 60,000 won per trap, which can save enormous budgets compared to the budget required to develop jamming compatible GPS equipment (about 100 million won per unit).

[Experimental Example]

Table 1 shows the performance of the blocking device by the number of GPS receiving satellites by radiating the virtual signal (jamming) per intensity (dBm). When the blocking device is not installed, when a quadrangular (hexahedral) And a case in which a blocking device is installed. The conical barrier was made of aluminum material at an angle (θ) of 60 degrees to the horizontal plane, a top diameter (width) of 25 cm, a height of 30 cm, and a thickness of 1 mm.

Century star
Radio disturbance
Radiation (dBm) Number of GPS receiving satellites Blocking device
Uninstalled Installing the interceptor Square Conical Normal (normal) 7 to 9 5 to 6 7 to 8 -90 5 to 6 4 to 5 6 to 7 -85 3 to 4 4 to 5 6 to 7 -80 2 to 3 3 to 4 5 to 6 -75 1-2 2 to 3 5 to 6 -70 0 to 1 1-2 3 to 4 -65 0 0 to 1 2 to 3 -60 0 0 0 to 1 -55 0 0 0

As can be seen in Table 1, the number of GPS receiving satellites was increased compared with the case where the shielding device was not installed at the same propagation disturbance signal strength, and the shielding effect of the conical shielding device was better than that of the square shielding device .

Table 2 compares the maximum distance that can be attacked by GPS radio disturbance with and without a shielding device.

In order to compare the approximate attackable maximum distance before and after the improvement, the free space path loss model as the following equation was applied.

[Equation 1]

Ls = 92.45 + 20logf + 20logD

Where Ls is path loss (dB), f is frequency (GHz), and D is distance (km).

For example, assuming that the maximum attackable distance (D) is 100 km, the path loss is 136.4 dB.

In order to give the receiving terminal the same propagation disturbance effect by the radio disturbance device, the maximum distance D that can be attacked by applying the path loss 126.4 dB considering the radio wave decay 10 dB by the blocking device was calculated to be 31.6 km.

Maximum distance to attack (radius) Before improvement (no barrier) After improvement (installation of barrier) 10 km 3.2 km 50 km 15.8 km 100 km 31.6 km 200 km 63.2 km

As can be seen in Table 2, the maximum distance that can be attacked is significantly reduced when a barrier is installed.

Table 3 compares the distances of field test and simulation results according to the shape of the shutoff device when installing the shutoff device.

Blocking device
Uninstalled Installing the interceptor Field experiment simulation Square Conical Square Conical 5 dB 15 dB 7.52 dB 14.30 dB 10 km 5.6 km 1.8 km 4.5 km 2.0 km 50 km 28.1 km 8.9 km 22.3 km 10.0 km 100 km 56.2 km 17.8 km 44.7 km 20.0 km 200 km 112.2 km 35.6 km 89.3 km 40.0 km ratio 1.8 times 5.4 times 2.2 times 5 times

Table 4 shows the results of tests (on-site tests) and computer simulations after launching the actual simulated disturbance radio waves for the case where no shielding device is installed, when a rectangular shielding device is installed, and when a conical shielding device is installed, The comparison of the blocking effect.

division Blocking device
Uninstalled Mounting of interrupter (gain value) Square Conical Field test - 5 dB 15 dB simulation - 7.52 dB 14.30 dB

As can be seen in Table 4, the blocking effect of the conical interrupter was two to three times better than that of the square interrupter. When the gain value is converted into the disturbance range (distance) of the enemy, there is a reduction effect of 1/2 for a quadrangle and 1/5 for a cone. In this way, although there is no 100% blocking effect, when the blocking device is installed, it has a blocking effect of 2 to 5 times as compared with the case of not installing the blocking device, and when tethered with other means such as striking and avoiding the disturbing radio source, .

Table 5 compares the maximum disturbance propagation strengths that can be carried out according to the presence and shape of the interrupter.

division Blocking device
Uninstalled Installing the interceptor Square Conical Peak value (dBm) -85 -80 -70 Expected effect - 5 dB 15 dB

As can be seen in Table 5, the blocking effect of the non-installed contrast square increased 1.8 times and the cone blocking effect increased 5.4 times.

Table 6 compares the reception value of the horizontal signal (disturbance wave) and the reception value of the vertical signal (satellite signal) according to the presence / absence of the blocking device and the shape, The received signal values are compared with each other and the performance of the isolator is calculated based on the difference value.

division Blocking device
Uninstalled Installing the interceptor Square Conical Signal value
(dB) level -3.47 -10.03 -10.05 Perpendicular 6.65 7.53 14.27 Difference value 10.02 17.58 24.32 Expected effect 7.52 14.30

As can be seen in Table 6, the blocking effect of the non-installed contrast square was increased 2.2 times and the cone blocking effect was increased 5 times.

10: GPS antenna
20: Radio disturbance shielding film
30: GPS satellite
40: GPS radio disturbing device
50: GPS information (vertical wave)
60: Disturbance radio wave (horizontal wave)
70: ground line

Claims (8)

A GPS (Global Positioning System) antenna includes a metal shielding film installed to surround the antenna,
Wherein the metal shielding film is grounded.
The method according to claim 1,
Wherein the metal shielding film blocks the GPS disturbance wave received by the horizontal wave and receives the GPS information from the GPS satellite with a vertical wave.
The method according to claim 1,
Wherein the metal shielding film is formed in a semi-cone shape having a larger diameter and an upper opening toward the upper side.
The method according to claim 1,
Wherein an angle between a side surface and a horizontal plane of the metal shielding film is 50 to 70 degrees.
The method according to claim 1,
Wherein the metal shielding film is made of one or more alloys selected from aluminum, stainless steel, silver, copper and chromium.
The method according to claim 1,
And a radio wave reflecting coating layer or a radio wave absorbing coating layer is formed on the surface of the metal shielding film.
The method according to claim 1,
Wherein the GPS signal is used for military or civil use.
Installing a metal shielding film to surround the GPS antenna; And
And grounding the metal shielding film.

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