Methods of counteraction to means of electronic reconnaissance of the enemy during the operation of pulse-Doppler onboard radars of fighters for radiation

2021 ◽  
Author(s):  
A.V. Bogdanov ◽  
D.V. Zakomoldin ◽  
I.V. Kochetov ◽  
S.I. Akimov
Keyword(s):  
Radiation Power ◽  
Group Actions ◽  
Radar System ◽  
Radar Signal ◽  
Airborne Radar ◽  
Energy Potential ◽  
Advantages And Disadvantages ◽  
Radar Systems ◽  
Pulse Doppler ◽  
Technical Measures

The article proposes methods of counteraction to the enemy's electronic reconnaissance means, both for a duel situation and for group actions of fighters, analyzes their advantages and disadvantages, identifies limitations on their use. The physical meaning of these methods is to ensure the secrecy of the operation of on-board radar systems for radiation, due to the variation in the energy potential of the station, in particular, the time of coherent energy accumulation in narrow-band Doppler filters when receiving signals reflected from air targets and the radiation power of the transmitter of the on-board radar system when forming sounding radar signal packs. In the article, along with the methods of ensuring the secrecy of the operation of onboard radar systems of fighters, which make it possible to carry out technical measures only after radar contact with an air target equipped with electronic reconnaissance means, which leads to a decrease in their effectiveness, methods for controlling the secrecy of the operation of onboard radar systems of fighters are additionally given, allowing to provide stealth with a given probability in the dynamics of the approach of a fighter with its emitting airborne radar system with an air target, equipped with electronic reconnaissance means. In addition, it should be noted the method of managing the energy secrecy of airborne radar systems during group actions of fighters, within the framework of the development of which the possibility of summing up the powers emitted by the transmitters of the onboard radar systems of fighters when they work together for radiation in the position of conducting electronic reconnaissance is taken into account. Implementation of the developed methods will allow: to increase the survivability of fighters, and to an increase in this indicator, both the ensured secrecy of the operation of onboard radar systems of fighters for radiation and the implementation of the multi-position principle of building radar systems, given in the method of stealth control of the onboard radar system of fighters during group actions of fighters. to expand the combat capabilities of fighters, due to the fact that the covert operation of the onboard radar systems of fighters for radiation excludes the possibility of reconnaissance of the parameters of the sounding signal and, as a result, the possibility of setting active interference is excluded.

scholarly journals Probabilistic analysis of ambiguities in radar echo direction of arrival from meteors

2020 ◽  
Author(s):  
Daniel Kastinen ◽  
Johan Kero
Keyword(s):  
Bayesian Method ◽  
Direction Of Arrival ◽  
Radar System ◽  
Stable Region ◽  
Radar Signal ◽  
Ambient Atmosphere ◽  
Radar Systems ◽  
Mu Radar ◽  
Meteor Trail ◽  
The Antarctic

Abstract. Meteors and hard targets produce coherent radar echoes. If measured with an interferometric radar system, these echoes can be used to determine the position of the target through finding the Direction Of Arrival (DOA) of the incoming echo onto the radar. If the DOA of meteor trail plasma drifting with the ambient atmosphere is determined, the neutral wind at the observation altitude can be calculated. Specular meteor trail radars have become widespread scientific instruments to study atmospheric dynamics. Meteor head echo measurements also contribute to studies of the atmosphere as the meteoroid input of extraterrestrial material is relevant for a plethora of atmospheric phenomena. Depending on the spatial configuration of radar receiving antennas and their individual gain patterns, there may be an ambiguity problem when determining the DOA of an echo. Radars that are theoretically ambiguity free are known to still have ambiguities that depend on the total radar Signal to Noise Ratio (SNR). In this study we investigate robust methods which are easy to implement to determine the effect of ambiguities on any hard target DOA determination by interferometric radar systems. We apply these methods specifically to simulate four different radar systems measuring meteor head and trail echoes using the multiple signal classification (MUSIC) DOA determination algorithm. The four radar systems are the middle and upper atmosphere (MU) radar in Japan, a generic Jones 2.5λ specular meteor trail radar configuration, the Middle Atmosphere Alomar Radar System (MAARSY) radar in Norway and the The Program of the Antarctic Syowa Mesosphere Stratosphere Troposphere Incoherent Scatter (PANSY) radar in the Antarctic. We also examined a slightly perturbed Jones 2.5λ configuration used as a meteor trail echo receiver for the PANSY radar. All the results are derived from simulations and their purpose is to grant understanding of the behaviour of DOA determination. General results are: there may be a region of SNRs where ambiguities are relevant; Monte Carlo simulation determines this region and if it exists; the MUSIC function peak value is directly correlated with the ambiguous region; a Bayesian method is presented that may be able to analyse echoes from this region; the DOA of echoes with SNRs larger then this region are perfectly determined; the DOA of echoes with SNRs smaller then this region completely fail to be determined; the location of this region is shifted based on the total SNR versus the channel SNR in the direction of the target; asymmetric subgroups can cause ambiguities even for ambiguity free radars. For a DOA located at the zenith, the end of the ambiguous region is located at 17 dB SNR for the MU radar and 3 dB SNR for the PANSY radar. The Jones radars are usually used to measure specular trail echoes far from zenith. The ambiguous region for a DOA at 75.5° elevation and 0° azimuth ends at 12 dB SNR. Using the Bayesian method it may be possible to analyse echoes down to 4 dB SNR for the Jones configuration, given enough data points from the same target. The PANSY meteor trail echo receiver did not deviate significantly from the generic Jones configuration. The MAARSY radar could not resolve arbitrary DOAs sufficiently well to determine a stable region. However, if the DOA search is restricted to 70° elevation or above by assumption, stable DOA determination occurs above 15 dB SNR.

Formation of the appearance of a promising airborne radar system for a helicopter in the Arctic region of the RF

2021 ◽  
Author(s):  
A.I. Kanashchenkov ◽  
A.E. Ananenkov ◽  
A.M. Matveev ◽  
D.A. Okhotnikov
Keyword(s):  
Arctic Region ◽  
Radar System ◽  
Information Support ◽  
The Arctic ◽  
Airborne Radar ◽  
Radar Systems ◽  
Equipment Construction ◽  
Principles Of Design ◽  
The Arctic Region

The intensification of the development of the Arctic region requires an increase in the intensity of transport support, one of the most common types of which is helicopter transport. One of the ways to improve flight safety is to equip helicopter equipment with highly informative onboard radar stations. It is necessary to justify the appearance, technical characteristics and principles of creating a promising radar system for helicopters. In this paper, the concept of building a promising airborne radar system for a helicopter in the Arctic region of the Russian Federation is proposed and considered. The main tasks are defined, on the basis of which the requirements for the technical characteristics of the complex are formulated. The variants of equipment construction based on the existing scientific and technical groundwork with the use of the basic principles of design and organization of serial production of the 4++generation are considered. The use of onboard radar systems will improve the quality of information support for pilots and will improve the safety of helicopter transport in the context of the intensification of development of the Arctic region.

scholarly journals Detecting and Mitigating Wind Turbine Clutter for Airspace Radar Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Wen-Qin Wang
Keyword(s):  
Wind Turbine ◽  
Doppler Radar ◽  
Wind Farms ◽  
Doppler Frequency ◽  
Radar Signal ◽  
Radar Systems ◽  
Resolution Imaging ◽  
Pulse Doppler ◽  
Pulse Doppler Radar ◽  
Mitigation Technique

It is well recognized that a wind turbine has a large radar cross-section (RCS) and, due to the movement of the blades, the wind turbine will generate a Doppler frequency shift. This scattering behavior may cause severe interferences on existing radar systems including static ground-based radars and spaceborne or airborne radars. To resolve this problem, efficient techniques or algorithms should be developed to mitigate the effects of wind farms on radars. Herein, one transponder-based mitigation technique is presented. The transponder is not a new concept, which has been proposed for calibrating high-resolution imaging radars. It modulates the radar signal in a manner that the retransmitted signals can be separated from the scene echoes. As wind farms often occupy only a small area, mitigation processing in the whole radar operation will be redundant and cost inefficient. Hence, this paper uses a transponder to determine whether the radar is impacted by the wind farms. If so, the effects of wind farms are then mitigated with subsequent Kalman filtering or plot target extraction algorithms. Taking airborne synthetic aperture radar (SAR) and pulse Doppler radar as the examples, this paper provides the corresponding system configuration and processing algorithms. The effectiveness of the mitigation technique is validated by numerical simulation results.

scholarly journals Broadband radar invisibility with time-dependent metasurfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
V. Kozlov ◽  
D. Vovchuk ◽  
P. Ginzburg
Keyword(s):  
Signal Processing ◽  
Metal Plate ◽  
Primary Objective ◽  
Radar System ◽  
Radar Signal ◽  
Surveillance Systems ◽  
Radar Systems ◽  
Reliable Performance ◽  
Promising Solution ◽  
Radar Countermeasure

AbstractConcealing objects from interrogation has been a primary objective since the integration of radars into surveillance systems. Metamaterial-based invisibility cloaking, which was considered a promising solution, did not yet succeed in delivering reliable performance against real radar systems, mainly due to its narrow operational bandwidth. Here we propose an approach, which addresses the issue from a signal-processing standpoint and, as a result, is capable of coping with the vast majority of unclassified radar systems by exploiting vulnerabilities in their design. In particular, we demonstrate complete concealment of a 0.25 square meter moving metal plate from an investigating radar system, operating in a broad frequency range approaching 20% bandwidth around the carrier of 1.5 GHz. The key element of the radar countermeasure is a temporally modulated coating. This auxiliary structure is designed to dynamically and controllably adjust the reflected phase of the impinging radar signal, which acquires a user-defined Doppler shift. A special case of interest is imposing a frequency shift that compensates for the real Doppler signatures originating from the motion of the target. In this case the radar will consider the target static, even though it is moving. As a result, the reflected echo will be discarded by the clutter removal filter, which is an inherent part of any modern radar system that is designed to operate in real conditions. This signal-processing loophole allows rendering the target invisible to the radar even though it scatters electromagnetic radiation.

Methods and algorithms of angular estimation with super-resolution for aviation airborne radar systems

2021 ◽  
Author(s):  
V.S. Verba ◽  
V.I. Merkulov ◽  
V.S. Chernov
Keyword(s):  
Antenna Arrays ◽  
Super Resolution ◽  
Radar System ◽  
Total Output ◽  
Technical Literature ◽  
Advantages And Disadvantages ◽  
Radar Systems ◽  
Ring Antenna ◽  
Angular Coordinates ◽  
Four Quadrant

In the practical application of aircraft, there may be situations when it is not possible to resolve radar target signals in the measurement channels of range, speed and angular coordinates in the on-board radar system. In these situations, it is advisable to use angular estimation procedures with super-resolution in the onboard radar system. Various methods and algorithms of angular estimation with super-resolution are known, each of which has its own advantages and disadvantages. At the same time, there is no information in the available scientific and technical literature about the algorithms of angular estimation with super-resolution used in the onboard radar system, knowledge of which is necessary when designing promising onboard radar systems. The article systematizes and analyzes the methods and algorithms of angular estimation with super-resolution. The classification of methods of angular estimation with superresolution is given. The generalized information about the known one-dimensional and twodimensional methods and algorithms of angular estimation is given. The algorithms proposed for use in flat antenna arrays, concentric ring antenna arrays, ring antenna arrays, round four-quadrant antenna arrays, flat antenna arrays with a total output signal are considered. It is noted that the features of the construction of radar homing heads include a reduction in the total number of information processing channels achieved by combining antenna elements into sublattices, the output signals of which are used to estimate the angular coordinates of radiation sources. The specificity of such antenna arrays is that the antenna sublattices have radiation patterns that are narrower than those of weakly directed antenna elements. In addition, the distance between the antenna modules can significantly exceed the distance between the antenna elements in a conventional antenna array and at the same time significantly exceed the wavelength size. To determine the possibilities of applying in practice the algorithms of angular two-dimensional estimation with super-resolution considered in the article in the onboard radar system, it is necessary to conduct special studies.

scholarly journals Probabilistic analysis of ambiguities in radar echo direction of arrival from meteors

2020 ◽  
Vol 13 (12) ◽  
pp. 6813-6835
Author(s):  
Daniel Kastinen ◽  
Johan Kero
Keyword(s):  
Bayesian Method ◽  
Middle Atmosphere ◽  
Direction Of Arrival ◽  
Radar System ◽  
Stable Region ◽  
Radar Signal ◽  
Radar Systems ◽  
Mu Radar ◽  
Meteor Trail ◽  
The Antarctic

Abstract. Meteors and hard targets produce coherent radar echoes. If measured with an interferometric radar system, these echoes can be used to determine the position of the target through finding the direction of arrival (DOA) of the incoming echo onto the radar. Depending on the spatial configuration of radar-receiving antennas and their individual gain patterns, there may be an ambiguity problem when determining the DOA of an echo. Radars that are theoretically ambiguity-free are known to still have ambiguities that depend on the total radar signal-to-noise ratio (SNR). In this study, we investigate robust methods which are easy to implement to determine the effect of ambiguities on any hard target DOA determination by interferometric radar systems. We apply these methods specifically to simulate four different radar systems measuring meteor head and trail echoes, using the multiple signal classification (MUSIC) DOA determination algorithm. The four radar systems are the Middle And Upper Atmosphere (MU) radar in Japan, a generic Jones 2.5λ specular meteor trail radar configuration, the Middle Atmosphere Alomar Radar System (MAARSY) radar in Norway and the Program of the Antarctic Syowa Mesosphere Stratosphere Troposphere Incoherent Scatter (PANSY) radar in the Antarctic. We also examined a slightly perturbed Jones 2.5λ configuration used as a meteor trail echo receiver for the PANSY radar. All the results are derived from simulations, and their purpose is to grant understanding of the behaviour of DOA determination. General results are as follows: there may be a region of SNRs where ambiguities are relevant; Monte Carlo simulation determines this region and if it exists; the MUSIC function peak value is directly correlated with the ambiguous region; a Bayesian method is presented that may be able to analyse echoes from this region; the DOA of echoes with SNRs larger than this region are perfectly determined; the DOA of echoes with SNRs smaller than this region completely fail to be determined; the location of this region is shifted based on the total SNR versus the channel SNR in the direction of the target; and asymmetric subgroups can cause ambiguities, even for ambiguity-free radars. For a DOA located at the zenith, the end of the ambiguous region is located at 17 dB SNR for the MU radar and 3 dB SNR for the PANSY radar. The Jones radars are usually used to measure specular trail echoes far from zenith. The ambiguous region for a DOA at 75.5∘ elevation and 0∘ azimuth ends at 12 dB SNR. Using the Bayesian method, it may be possible to analyse echoes down to 4 dB SNR for the Jones configuration when given enough data points from the same target. The PANSY meteor trail echo receiver did not deviate significantly from the generic Jones configuration. The MAARSY radar could not resolve arbitrary DOAs sufficiently well enough to determine a stable region. However, if the DOA search is restricted to 70∘ elevation or above by assumption, stable DOA determination occurs above 15 dB SNR.

scholarly journals Broadband Radar Invisibility with Time-Dependent Metasurfaces

2021 ◽  
Author(s):  
Vitali Kozlov ◽  
Dmytro Vovchuk ◽  
Pavel Ginzburg
Keyword(s):  
Signal Processing ◽  
Metal Plate ◽  
Primary Objective ◽  
Radar System ◽  
Radar Signal ◽  
Surveillance Systems ◽  
Radar Systems ◽  
Reliable Performance ◽  
Promising Solution ◽  
Radar Countermeasure

Abstract Concealing objects from interrogation has been a primary objective since the integration of radars into surveillance systems. Metamaterial-based invisibility cloaking, which was considered a promising solution, did not yet succeed in delivering reliable performance against real radar systems, mainly due to its narrow operational bandwidth. Here we propose an approach, which addresses the issue from a signal-processing standpoint and, as a result, is capable of coping with the vast majority of unclassified radar systems by exploiting vulnerabilities in their design. In particular, we demonstrate complete concealment of a 0.25 square meter moving metal plate from an investigating radar system, operating in a broad frequency range approaching 20% bandwidth around the carrier of 1.5GHz. The key element of the radar countermeasure is a temporally modulated coating. This auxiliary structure is designed to dynamically and controllably adjust the reflected phase of the impinging radar signal, which acquires a user-defined Doppler shift. A special case of interest is imposing a frequency shift that compensates for the real Doppler signatures originating from the motion of the target. In this case the radar will consider the target static, even though it is moving. As a result, the reflected echo will be discarded by the clutter removal filter, which is an inherent part of any modern radar system that is designed to operate in real conditions. This signal-processing loophole allows rendering the target invisible to the radar even though it scatters electromagnetic radiation.

Method of controlling the parameters of the pulse-Doppler onboard radar station while ensuring the energy stealth of its operation on radiation

2021 ◽  
Author(s):  
A.V. Bogdanov ◽  
D.V. Zakomoldin ◽  
S.I. Akimov
Keyword(s):  
Optimal Control ◽  
Radar System ◽  
Radar Signal ◽  
Mathematical Apparatus ◽  
Fighter Aircraft ◽  
Control Signals ◽  
Local Quality ◽  
Theory Of Optimal Control ◽  
Pulse Doppler ◽  
And Control

In the article, based on the mathematical apparatus of the statistical theory of optimal control in the state space, the synthesis of a method for controlling the parameters of the pulse-Doppler onboard radar system (BRLS) of a fighter aircraft is presented, in the interests of ensuring the energy stealth of its operation on radiation with a given probability, when detecting an air target-the carrier of a radio intelligence station, the optimal minimum local quality functional. The efficiency of the synthesized method is also evaluated on the basis of modeling. As part of the synthesis, the quality functional was determined and control signals were obtained for the parameters of the radar operation, which make it possible to ensure the energy stealth of the fighter's radar operation with a given probability in the process of approaching the radar carriers and the radio intelligence station (RTR). The indicators of the control signal efficiency determine the probability of correct detection of the radar of the air target carrier of the RTR station and the probability of non-detection by the RTR station of the sounding radar signal in the process of their approach. Based on the simulation, the effectiveness of the control signals is evaluated, which shows that in the process of approaching the fighter and the RTR carrier station, the energy stealth of the radar operation is provided with a given probability by controlling the parameters of the radar operation.

Automotive Radars

2017 ◽  
Author(s):  
Sujeet Patole ◽  
Murat Torlak ◽  
Dan Wang ◽  
Murtaza Ali
Keyword(s):  
Signal Processing ◽  
Pedestrian Detection ◽  
Radar Signal ◽  
Automotive Radar ◽  
Estimation Algorithms ◽  
Radar Systems ◽  
Starting Point ◽  
Processing Techniques ◽  
Automotive Radars ◽  
Signal Processing Techniques

Automotive radars, along with other sensors such as lidar, (which stands for “light detection and ranging”), ultrasound, and cameras, form the backbone of self-driving cars and advanced driver assistant systems (ADASs). These technological advancements are enabled by extremely complex systems with a long signal processing path from radars/sensors to the controller. Automotive radar systems are responsible for the detection of objects and obstacles, their position, and speed relative to the vehicle. The development of signal processing techniques along with progress in the millimeter- wave (mm-wave) semiconductor technology plays a key role in automotive radar systems. Various signal processing techniques have been developed to provide better resolution and estimation performance in all measurement dimensions: range, azimuth-elevation angles, and velocity of the targets surrounding the vehicles. This article summarizes various aspects of automotive radar signal processing techniques, including waveform design, possible radar architectures, estimation algorithms, implementation complexity-resolution trade-off, and adaptive processing for complex environments, as well as unique problems associated with automotive radars such as pedestrian detection. We believe that this review article will combine the several contributions scattered in the literature to serve as a primary starting point to new researchers and to give a bird’s-eye view to the existing research community.

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