KR20190001054A - Spoofing system for satellite navigation and method thereof - Google Patents

Abstract

The present invention relates to a spoofing system for satellite navigation and a method thereof which protects a friendly weapon system from spoofing signals in a transmission effect range of spoofing signals transmitted by friendly forces, and applies effects of spoofing signals to enemy forces only. According to the present invention, the spoofing system for satellite navigation comprises: a spoofing code generation unit (11) to add flag information indicating a spoofing signal to an empty area in a bit stream of a pseudo-random noise (PRN) code of any one navigation satellite (21) selected among a plurality of navigation satellites to generate a spoofing code; a spoofing signal transmission unit (12) to modulate the spoofing code to transmit a modulated spoofing code within an operating range; and an identification information providing unit (13) to supply information of the selected navigation satellite (21) corresponding to the PRN code used as the spoofing code to a friendly receiver within the operating range. According to the present invention, the spoofing method for satellite navigation comprises: a PRN code selection step (S110) of selecting any one among PRN codes of a plurality of navigation satellites (21) received within an operating range; a spoofing code generation step (S120) of including a flag bit in the selected PRN code to generate a spoofing code; a spoofing information providing step (S130) of supplying information of a navigation satellite (21) providing the PRN code used in generation of the spoofing code to a friendly receiver; and a spoofing signal transmission step (S140) of modulating the spoofing code to transmit a modulated spoofing code within the operating range.

Description

TECHNICAL FIELD [0001] The present invention relates to a satellite navigation apparatus,

The present invention relates to a satellite navigation deception system and method for allowing a friendly weapon system to be protected from a deception signal in an influence range of a deception signal transmitted from a friendly force,

The Global Navigation Satellite System (GNSS) is a system that provides information on the altitude velocity of an object using a satellite orbiting a space orbit. The Global Positioning System (GPS) developed by the US Department of Defense, GLONASS (GLOBAL NAvigation Satellite System), Galileo (European Union) and Vader WU (China).

While the satellite navigation system has been widely used in weapons such as fighter aircraft, traps, guided missiles, and tanks, the accuracy of the weapon system has been greatly improved, whereas when the satellite navigation signal reaches the ground, the signal strength is reduced to about -130 dBm (ICD, Interface Control Document), which includes the signaling system of the satellite navigation system, has been exposed to the problem that the weapon system is vulnerable to radio disturbance attacks on the satellite navigation signal.

Especially, within the range of the influence of the radio disturbance attack, since the enemy army as well as the army weapon system are disabled by the radio disturbance, the protection against the ally is necessary when the radio disturbance attack is to be performed.

The form of the propagation disturbance with respect to the satellite navigation signal is that the jamming and the navigation receiver, which transmit signals higher than the reception strength of the satellite navigation signal in the frequency band used by the satellite navigation signal, (Spoofing).

Of these, the same structure as the satellite navigation signal is used for the above-mentioned deed, but includes false navigation data or pseudo distance information so that the receiver can not receive accurate position, speed, and time (PVT) information. The degenerator transmits false information for the purpose of causing the receiver to generate an error in the application environment by obtaining a deception signal having false information and inducing an error in navigation. In terms of maturity, it is important to generate a deception signal so that the target receiver has similar characteristics to the actual satellite navigation signal.

Therefore, although it is possible to detect a jamming attack that transmits a strong signal, it is difficult to recognize that a low-power jamming signal can not be detected. Thus, deception propagation disturbance requires protection against allied forces, and these measures can be used to attack enemy weapons systems without harming them.

On the other hand, the following prior art reference discloses a technique relating to a 'satellite navigation composite jamming signal generating device and a control method thereof'.

KR 10-1534662 B1

It is an object of the present invention to provide a satellite navigation deception system and method capable of disabling an enemy weapon system through a protection measure against a friend in the case of a deception type radio disturbance attack.

According to another aspect of the present invention, there is provided a satellite navigation defacement system comprising: a satellite navigation defacement system for indicating a deceptive signal in an empty area of a bit stream of a PRN (pseudo-random noise) code of a selected one of a plurality of navigation satellites An indicator signal generator for modulating the tamper-resistant code and sending it to the operational area, and a control unit for controlling the operation of the navigation satellite information To the friendly receiver in the operation area.

And a code generation control unit for changing the PRN code used in the default code generation unit and transmitting the changed PRN code to the default code generation unit.

An identification information receiving unit for receiving information of a navigation satellite used by another external GPS navigation system to generate a malicious code, a signal receiving unit for receiving a signal of the navigation satellite, detecting the navigation satellite and a synchronizing signal, And a satellite signal receiving unit for detecting flag bits included in the PRN signal corresponding to the navigation satellite.

Meanwhile, the navigation method of the navigation method according to the present invention includes: a PRN code selection step of selecting any of PRN codes of a plurality of navigation satellites received in an operation area; A deemed information providing step of providing a friendly satellite receiver with information of a navigation satellite providing a PRN code used for generating the deception code, a deem information providing step of modifying the deem code and transmitting it to the operation area And a signal sending step.

Generating the deception code based on any one of a position of the navigation satellite, an effect degree of the deception code, a time transition, a navigation satellite in the operation region, and a movement path of an enemy weapon system after the deception signal delivery step And determining whether to change the PRN code used to make the PRN code change.

And when it is determined to change the PRN code for generating the deception code in the deemed code change determination step, the deemed code generation step is returned to the deemed code generation step.

If it is determined that the PRN code for generating the deceptive code should not be changed in the debit code change decision step, a status termination determination step for determining whether or not the status is terminated is performed, and in the status termination determination step, And then returns to the deception signal sending step.

According to the satellite navigation deception system and method of the present invention having the above configuration, by tracking and applying the optimal deception code capable of deceiving the enemy weapon system, it is possible to detect only the enemy weapon system, It is possible to use the weapon system by using satellite navigation normally.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a satellite navigation deception system according to the present invention; FIG.
FIG. 2 is a diagram showing a state in which a radio navigation disturbance is caused in a satellite navigation deception system according to the present invention in the field of a friendly weapon system and an enemy weapon system; FIG.
FIG. 3 is a flowchart showing a satellite navigation deception method according to the present invention. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

The satellite navigation deception system 10 according to the present invention includes a flag indicating that the signal is a deceptive signal in a free area of a bit stream of a PRN (Pseudo-random Noise) code of any one of navigation satellites selected from a plurality of navigation satellites 21 (12) for modulating the deception code and transmitting the deception code into the operation area, and a dequeue signal generating unit (12) for generating a dequeue code by adding the information And an identification information providing unit (13) for providing the selected navigation satellite (21) information to the friendly receiver in the operation area.

In the following description, GPS is used as an example among various satellite navigation systems. However, the present invention is not limited to GPS, and a representative term including the same type of codes used in other GPS navigation systems other than the GPS As shown in FIG.

The deception code generating unit 11 adds flag information indicating a deemed signal to a free area of a bit string of a pseudo-random number (PRN) code of a navigation satellite to generate deem code.

The PRN code is a binary code and has a code division multiple access (CDMA) code unique to each satellite. The satellite navigation receiver separates the satellite with the PRN code. The satellite navigation receiver generates a PRN code of each satellite inputted in advance based on GPS time and compares it with the arrival time of a PRN code of each satellite received to calculate a time difference to calculate a pseudorange.

One of the PRN codes is called a C / A code (Coarse / Acquisition code) or SPS (Standard Positioning Service) and is for general users. The other is a P code (Precision code) or PPS (Precise Positioning Service).

In this case, the P code is encrypted so that it can be used only by a limited user.

Since the present invention is applied to an inorganic system, the PRN code may include at least one of the C / A code and the P code, preferably both the C / A code and the P code.

For example, in a GPS satellite, the PRN code is composed of 1023 chips, of which there is an empty region. By including one or more flag bits here, it becomes a deception code so that it can be confirmed that the PRN code is a deception signal in a friendly weapon system.

The deception signal transmitting unit 12 modulates the deaf code and transmits it to the operation area, and may include a modulator, a carrier generator, a synchronous signal, an antenna, and the like. The deception signal transmitting unit 12 can be customized to operate according to the target receiver operating system, that is, GPS, GLONASS, Galilio, Vader, etc.

The identification information providing unit 13 provides the information of the navigation satellite corresponding to the PRN code used as the malicious code to the friendly receiver in the operating area. The identification information providing unit 13 transmits the identification information in various forms to identify the navigation satellite 21. The identification information providing unit 13 may be implemented using a wire / wireless communication device separate from the defacement signal transmitting unit 12 in order to provide the identification information to the friendly receiver. Further, the time point at which the identification information is provided may be the same time as or after the time when the PRN code is selected to generate the deception code, or may be the identification information before generating the PRN code as the predetermined information at the operating time and / It can also be shared.

The code generation control unit 14 determines which PRN code is used among a plurality of PRN codes corresponding to a plurality of navigation satellites, and changes the target code. As a criterion for selecting the PRN code, the code generation control unit 14 changes the effectiveness of deception by feedback from the receiver in the operational region, or selects the PRN code based on the receivable PRN code information in the operational region Or a PRN code that is close based on the position of the navigation satellite 21 but can not be received in the operating area or a PRN code that can be received in the coverage along the movement path or time trend of the target, The PRN code or the debit code can be changed by the multiplexed code generated by calculating the above PRN code.

The identification information receiving unit 15 receives the navigation satellite information used for generating the protection code for the allied weapon system provided in the other external defacement system, that is, the navigation satellite information, Can be implemented.

The satellite signal receiving unit 16 receives the signal of the navigation satellite 21 and detects the synchronization signal with the navigation satellite 21 and outputs the flag included in the PRN signal corresponding to the navigation satellite received by the identification information receiving unit 15 Bits. The satellite signal receiving unit 16 detects a deception signal including a flag among the navigation satellite signals based on the protection information provided by the other deception system and extracts a 1pps (pulse per second) signal of the navigation satellite and a 1pps / Or extract the fundamental frequency.

The satellite navigation deception system 10 according to the present invention transmits the deception signal to the enemy weapon system and the enemy weapon system in the field as shown in FIG. For example, a deception signal can be transmitted from the vehicle 22 equipped with the satellite navigation deception system 10, and the deaf signal is transmitted to both the friendly weapon system and the enemy weapon system in the operation area, Since the information that the signal is transmitted is transmitted, the deception signal is not affected.

FIG. 3 shows a flowchart according to the method of satellite navigation deception according to the present invention.

A method for deleting a navigation device according to the present invention includes: selecting a PRN code (S110) for selecting any one of PRN codes of a plurality of navigation satellites (21) received in an operating area; (S130) for providing information of the navigation satellite (21) providing the PRN code used for generating the deceptive code to the friendly receiver (S130); (S140) for modulating the tamper-resistant code and transmitting it to the operating area.

In the PRN code selecting step S110, the satellite navigation deception system 1 selects a PRN code corresponding to the navigation satellite 21 received in the operating area. In order to deceive the enemy weapon system 29 in the step of selecting the PRN code (S110), it is necessary to select the same code as the PRN code normally received from the navigation satellite 21 and simulate the signal strength and the like.

In the deception code generating step S120, the defacement code generating unit 11 generates a deception code by including a flag bit in the RN code selected in the step of selecting the PRN code (S110).

In the degenerate information providing step S130, the identification information providing unit 13 transmits information about the navigation satellite corresponding to the PRN code used for generating the deception code among the plurality of navigation satellites 21 to the friendly weapon system 23 24) < / RTI > In the degenerate information providing step S130, allied weapon systems 23, 24 and 25 such as allied airplane 23, guided weapon 24, and tram 25, It is provided to all friendly weapons systems to be entered.

The time point at which the information on the navigation satellite 21 used for generating the malicious code in the malicious information providing step S130 may be performed at the same time as or after the selection of the PRN code before generating the malicious code, It is also possible that the identification information is provided first according to the determined rule, and thereafter, the deceptive code generation unit 11 selects the PRN code according to the predetermined rule.

In the malignant signal sending step S140, the malignant signal transmitting unit 12 modulates the malignant code and transmits the malignant signal into the operation area.

In the deception code change determining step (S150), it is determined whether the PRN code in use is changed with the deception code. The code generation control unit 14 generates the PRNs used for generating the deception code based on any one of the position of the navigation satellite, the effect of the deception code, the time trend, the navigation satellite fluctuation within the coverage, The code generation control unit 14 determines whether or not to change the PRN code used for generating the malicious code.

If it is determined to change the PRN code used for generating the malicious code in the malicious code change determination step S150, the process returns to the malicious code generation step S120 and the above process is performed again.

In step S 150, the code generation control unit 14 determines the change of the PRN code used for generating the deception code and returns to the deception code generation step S 120, And transmitted to the friendly weapon systems 23, 24 and 25 through the identification information providing unit 13, thereby preventing the damage of the radio disturbance in real time in the friendly weapon systems.

On the other hand, if it is determined in step S150 that the PRN code in use is not to be changed to the deception code, the status end determination step S160 is performed.

If it is determined that the situation has not ended, the process returns to the deception signal sending step (S140). If it is determined that the situation is ended, the process ends.

10: Satellite Legitimate Deception System
11: Tricky code generation unit
12: Trick signal transmitter
13: Identification information provider
14: Code generation control section
15: Identification information receiving section
16: satellite signal receiving section
21: Navigation satellite
22: Vehicles equipped with satellite legitimate deception system
23: Friendly aircraft
24: Friendly guided weapons
25: Friendly tanks
29: Enemy aircraft
S110: PRN code selection step
S120: Deception code generation step
S130: Deceptive information providing step
S140: Deception signal transmission step
S150: Deception code change decision step
S160: situation end determination step

Claims (7)

A pilot code generating unit for generating pilot symbols by adding flag information indicating a pilot signal to a free region of a bit stream of a PRN (Pseudo-random Noise) code of a selected one of the plurality of navigation satellites;
A deemed signal transmitting unit for modulating the deemed code and sending it out to the operating area;
And an identification information providing unit for providing the selected navigation satellite information corresponding to the PRN code used as the debit code to the friendly receiver in the operation area. The method according to claim 1,
Further comprising a code generation control unit for changing a PRN code used in the default code generation unit and transmitting the changed PRN code to the default code generation unit. The method according to claim 1,
An identification information receiving unit for receiving information of a navigation satellite used by another external GPS navigation system to generate a malicious code;
Further comprising a satellite signal receiving unit for receiving a signal of the navigation satellite, detecting a synchronization signal with the navigation satellite, and detecting flag bits included in the PRN signal corresponding to the navigation satellite received by the identification information receiving unit Satellite navigation deception system. A PRN code selection step of selecting any one of the PRN codes of a plurality of navigation satellites received in the operation area,
Generating a debit code by including a flag bit in the selected PRN code;
A deemed information providing step of providing information of a navigation satellite providing a PRN code used for generation of the deception code to a friendly receiver;
And a deemed signal transmitting step of modulating the deemed code and sending it out to the operating area. 5. The method of claim 4,
After the deception signal sending step,
The PRN code used to generate the defacement code based on any one of the position of the navigation satellite, the effectiveness of the deception code, the time trend, the navigation satellite in the operation area, and the movement path of the enemy weapon system Further comprising a deception code change decision step of deciding whether or not to change the deception code. 6. The method of claim 5,
If it is determined that the PRN code for generating the malicious code is to be changed in the malicious code change determination step,
And the return to the deception code generation step. 6. The method of claim 5,
If it is determined that the PRN code for generating the deception code should not be changed in the deemed code change decision step,
A situation end determination step of determining whether or not the situation is ended is performed,
And if it is determined that the situation has not been terminated in the situation end determination step, it is returned to the deception signal delivery step.

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