RU2536013C2 - Method of detecting stolen vehicles from presence of signal suppressors - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: control points are placed on motorways and are provided with receivers for detecting a source of interference for GPS and GSM signals. Photographic and video capturing of vehicles on the motorway is performed upon detecting interference and the data are transmitted to a remote server. Data received at the server from multiple control points are processed to detect licence plate matches. Data on said licence plates and direction of movement are transmitted to road patrol service posts nearest to the last point where the interference was detected.

EFFECT: high efficiency of detecting stolen vehicles.

2 dwg

Description

The invention relates to the field of technology of automotive burglar alarms and can be used to determine the location of stolen cars in the process of their movement along highways.

Today, the acute problem of finding stolen cars. Known means of protection against car theft, such as, for example, "Autophone" bugs [1], allow you to track the position of the car using the GPS satellite navigation system, by the position of the radiating station of the GSM cellular operator. Car thieves are well aware of the presence of such bugs and, when hijacked, take measures to suppress them. Why use the jamming system as a cellular connection [2], and against GPS signals [3]. Already use and possibly will use "jammers" on other means of communication, for example 3G / UMTS 2100 MHz, COMA 450 MHz, 4G / LTE800 MHz, 4G / LTE2500 MHz. At the time of the car theft, the hijackers turn on the “jammers” and do not turn them off until the car is brought into the so-called “sedimentation tank” or a special underground garage that blocks GSM and GPS signals. Therefore, systems [1] are ineffective. In addition to using systems [1], it is advisable to search for a hijacker by the “jammers” themselves, i.e. determine the position of "jammers" and, accordingly, a potential hijacker.

The closest solution in this regard is the technology described in [3]. It consists in the following.

Suppressors pose a serious threat to the future of intelligent transport systems. Their use is prohibited by law, and their illegal use may be prosecuted. To know the exact number of suppressors working, you need to place the suppressor detectors at special points and record interference. Successful locations of such detectors for initial measurements can serve as trunk interchanges.

When conducting an interference detection test, recording was made using five static receivers located in the central part of the GATE laboratory.

Detection of the source of interference is based on monitoring the signal to noise ratio of the suppressor (JNR). In order to prosecute intruders, it is necessary to establish which suppressor is coming from the jammer. Therefore, the signal was analyzed in the time-frequency interval for the characteristic chirp signal of the suppressor. The gain of the input stage was set to a minimum value so that the input stage could cover high interference power.

Hijackers create a chirp impulse in the range from 9.4 to 44.9 MHz in the E1 / L1 frequency band (other frequency bands were not considered). The rest generate harmonic oscillations of 3 dB in a passband of about 0.92 MHz and have a temperature-dependent resonant frequency around the Galileo / GPS resonant frequency.

First, signals were recorded using a chirp suppressor located at a central point. The suppressor is located outside the vehicle in line of sight. Measurements in this position at a distance of 200 meters from the suppressor using short-term Fourier transforms of the signal clearly show the presence of the LFM signal.

During the second measurement, the suppressor was placed in the car. The car drove out of a certain position where the jammer was activated, and drove along the main street past the detector. Then the car turned around and drove the same way. Filmed JNR indicators.

Measurements of the degradation of the C / N0 value for GPS PRN9 in Figure 22 and for GATE PRN 46 show that the suppressor can be detected and identified in the zone of the distributed receiver network.

The next step in the development of an integrated network for monitoring interference is the availability of automotive GNSS receivers capable of detecting and reporting the presence of interference. For this scenario, the jammer was activated in one moving car, and in another car moving along the same road, measurements were made using the ipexSR receiver.

Both cars left one position. First, the jammer was turned on, after which the receiver was turned on with a random car in the gap. After 170 seconds, the car with the suppressor was parked at the curb, and the car with the receiver passed by, which is shown by a single burst on the graph. After 240 seconds, the car with the receiver turned around and drove past the jammer again. This is shown as a second surge after 310 seconds. After the receiver passed the parked car with the suppressor, the latter started off, caught up and overtook the car with the receiver after 450 seconds.

During this measurement, none of the vehicles could trace or receive the signal again. The synchronization violation message on all satellites can be used for rough localization of suppressors.

The analysis showed that the range of the suppressor is very dependent on the architecture of the receiver. In each scenario, suppressors had a strong effect. After detecting interference, it was necessary to mitigate their effect in the receiver. Softening methods such as short-term Fourier transforms or wave packets are provided. Using the IpexSR software interface, you can run and test such algorithms in real life.

The result of the above stated the need to take measures against the use of automotive suppressors. Detectors must be placed for accusations of using suppressors. This measure will also allow you to calculate the number of suppressors used. The degradation of GNSS positioning poses a threat to the use of intelligent transport systems designed to improve driving safety. Therefore, the prevention and mitigation of the effect of interference should be the subject of research for developers of automotive communications systems. Interference in GNSS systems must be dealt with in the same way as other road hazards.

This technology is selected as a prototype.

The advantage of the technology is that it shows the possibility of detecting jammers and can count them. The disadvantage of the technology is that it does not describe how to conduct the process of identifying an object by the presence of signal suppressors in it. According to this technology, it is not possible to identify a car with a hijacker among the total flow of cars.

Meanwhile, the detection of a stolen car is important for the capture of the hijacker. Very often during car theft, the car owner records the fact of the car theft after the car theft itself and signals to the police about the theft of the car too late when the hijacker has passed all the traffic police posts and may even have left for another area. That is why it is important to fix the process of identifying an object by the presence of signal suppressors in it. If this is done, it will be possible to catch the hijackers even before the moment when the car owner discovers the fact of theft.

The technical result of the claimed invention is to increase the detection efficiency of stolen cars.

The specified technical result is achieved due to the fact that the method of detecting stolen vehicles by the presence of signal suppressors, characterized by the use of static control points located on highways and containing receivers for detecting the interference source of GPS signals, operating on the basis of monitoring the signal-to-noise ratio of the jammer (JNR), characterized in that next to the receiver for detecting the source of interference of GPS signals, a receiver is installed for detecting the source of interference of GSM signals, at least one de-cameras and a wireless communication center, and radio interference is detected by antennas with a narrow radiation pattern, and when a source of interference of GPS signals and / or GSM signals is detected from an appropriate receiver, an alarm signal is sent through which a photo or video of vehicles located on the next camera is installed highway; then, the obtained information about the type of interference source of the radio signals and the received images are transmitted using the wireless communication node to a remote server on which data is recorded; the data collected on the server from a number of static control points installed in different places of the highway are further processed by extracting the same type of interference signals, which analyze the images of all cars passing by the static points, followed by determining the dynamics and direction of movement of the vehicles in which the group is located a source of radio interference, their license plates, and then upon detection of license plates of those vehicles that were recorded by security cameras at the time of detection Ia source interference, information on available cars and the dynamics of their motion is transmitted to the posts of traffic police officers who are in nearby areas from the last place where the last source of interference was detected.

The implementation of the invention

The claimed method can be implemented, for example, by building the next adaptive system. This allows the system to "adapt" to the existing local area. To do this, a static control point is placed in a given area. Select ranges for control (which type of signal suppressor we will identify and which ranges: GSM 900, DCS 1800, 3G / UMTS 2100, 3G / UMTS 900, CDMA 450, 4G / LTE800, 4G / LTE2500, Wi-Fi, etc.) . The system "remembers" the ratio of the noise / signal level (for each range for each value of the carrier frequency).

Further, the system can be configured by the operator "manually" based on the conditions:

- what type of signal suppressor we will identify (which ranges will be monitored);

- what is the alarm threshold (for example, excess signal / noise by 10 dB);

- will there be enough excess in the entire range (for example, in the entire GSM range) or is it sufficient only in some part of the range;

- the ability to compare the excess of signal-to-noise in one band with another (for example, a large signal level appeared sharply in the GSM DownLink band of 925-960 MHz, our system takes a close range of 900-920), if in this range there is also a sharp excess, it is likely that some kind of broadband interference is operating that is not of interest. If not, then most likely GSM signals are intentionally jammed and the system works. Similarly for other communication systems. That is, our system is more intelligent - when the operator sets this mode, our invention will detect not all signal suppressors in a row, but only those that work at frequencies of certain types of communications.

Reference data for assessing excess signal-to-noise ratio suppressors can be collected experimentally, for which a car is taken, different types of radio signal suppressors (“jammers”) are placed in it, then the car is tested by passing under the detectors at speeds, for example, from 1 to 180 km / h, and the detectors are raised to different levels of height. The system “remembers” the maximum and minimum parameters (signal / noise level, ranges, comparison with close ranges (see above)) when driving a car with a “jammer”, which allows the system to identify with a higher probability a car with a “jammer” in this local area at a particular installation at a certain height. An antenna system with a narrow radiation pattern gives a small "spot" under the detection system of jammers of radio signals, if it is located somewhere above.

Static control points (1) (see Figure 1, Figure 2) are placed on highways (11). Control stations (1) contain receivers for detecting the interference source of GPS signals (4) and receivers for detecting the interference source of GSM signals (5), which operate on the basis of monitoring the signal-to-noise ratio of the suppressor.

Near the receivers (4, 5), video cameras (2) and a wireless communication unit (6) are installed. Detection of radio interference by receivers (4, 5) is carried out by antennas (3) with a narrow radiation pattern.

If a source of interference of GPS signals and / or GSM signals is detected from an appropriate receiver, an alarm signal is sent through which a number of installed cameras (2) are used to take photo or video of vehicles (13) located on the highway (11) in areas (12) of the possible actions of "silencers".

The received information about the type of interference source of radio signals and the received images are transmitted to the microprocessor (7), which generates a data packet and transmits it via a wireless communication node (6) via the Internet (8) to a remote server (9) on which data is recorded .

The data collected on the server (9) from a set of static control points installed in different places of the highway (11) are further processed by extracting the same type of interference signals, which analyze the images of all cars passing by the static points (1), followed by determining the dynamics and the direction of movement of the cars (13), in the group of which there is a source of radio interference, and possibly isolating a specific car by analyzing data from more than one statistical point.

The selected group of cars (13) determine the license plates. The determination of the vehicle number can be performed, for example, using the KODOS-Auto vehicle number identification system [4].

Then, a comparison of license plates is made, and if a coincidence of license plates of those vehicles that were recorded by security cameras at the time of detecting the source of radio interference is detected, information about these vehicle numbers and dynamics of their movement is transmitted to posts (10) of the road patrol service located in the immediate vicinity of the last place where the last source of radio interference was recorded.

At posts (10), a road patrol stops cars to check documents with drivers. In the absence of a driver’s vehicle registration certificate, he can be detained as a potential hijacker or, if his documents are in order, but “jammers” are found in his car, he can also be detained and fined, because he violates the law, interfering with radio communication systems.

Information sources

1. http://www.autopulse.ru/item9867.html

2. http://www.bughunter.ru/prod/prod_08.php

3. http://gps-club.ru/gps_think/detail.php?ID=72435

4.http: //www.kodos.ru/production/auto/

Claims (1)

A method for detecting stolen vehicles by the presence of signal suppressors, characterized by the use of static control points located on highways and containing receivers for detecting a source of interference of GPS signals, operating on the basis of monitoring the signal-to-noise ratio of a jammer (JNR), characterized in that it is next to a receiver for detection a GPS signal interference source is installed by a receiver to detect a GSM signal interference source, at least one video camera and a wireless communication node, and radio interference detection carried out by antennas with a narrow radiation pattern, and when a source of interference of GPS signals and / or GSM signals is detected from the corresponding receiver, an alarm signal is sent through which a photo or video of cars on the highway is taken with a nearby installed camera; then, the obtained information about the type of interference source of the radio signals and the received images are transmitted using the wireless communication node to a remote server on which data is recorded; the data collected on the server from a number of static control points installed in different places of the highway are further processed by extracting the same type of interference signals, which analyze the images of all cars passing by the static points, followed by determining the dynamics and direction of movement of the vehicles in which the group is located a source of radio interference, their license plates, and then upon detection of license plates of those vehicles that were recorded by security cameras at the time of detection Ia source interference, information on available cars and the dynamics of their motion is transmitted to the posts of traffic police officers who are in nearby areas from the last place where the last source of interference was detected.

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