Abstract: In the synergy application of detection group for netted radar system, it has been difficult for commanders to quickly and correctly decide on group-building forms and control plans, which has led to difficulties in agile group-building and precise control, restricting the synergy detection efficiency of new air-space threats. On the basis of briefly describing the principle and complexity of human-computer decision fusion, this paper reveals the mechanism of human-computer decision fusion technology in generating synergy detection complexity and cracking the complexity of new air-space threats. It establishes the model of human-computer fused decision
Abstract: Intelligence era is coming. Distributed, netted, intelligent are the trend for radar detection system, has becoming the more and more important technical research area, also promote the evolution of radar netted detect and its application. Based on “Research on collaborative detection technology of early warning system”, aim to the new develop thinking about future, this paper researches the cross-disciplinary of complexity science and electronics science, a new concept named complex electronic system (CES) has proposed. Using network science theory to electronic system, the status and levels of CES netted-synergy also proposed, including CES netted-synergy matrix and status transfer matrix. Emergence and self-organizing is the most important characteristics of complex system, this paper puts forward a simple rule for CES self-organizing, its self-organized statues has been simulated in this paper, including self-organizing target and resources. When CES used for synergy detect, means the new system status for radar synergy detection, and give out netted-synergy, self-organizing intelligent system behaviors.
Abstract: The standardization of radar networking cooperative operation, is the basis of the operation management of the early warning grid (EWG), is the prerequisite of the EWG's cross-domain cooperation within the joint operation system, and is the important support of the forth-generation radar executing multifunction activities effectively and dynamically. Aiming on the standard procedure of the EWG, that is driven by the fusion and control center (FCC), a standardized order set basis factor (OSBF) is proposed to describe the EWG′s radar operation mission (ROM), the single radar′s radar task order (RTO) and radar control order (RCO). The ROM, RTO, RCO are attained by the linear combination of the proposed OSBF, which covers typical operation requirements such as early warning search, high precise track and identification, and guidance indication. This also enables the ROM, RTO and RTO order set to fulfill the need of different orders in complex application scenarios through adjusting the order′s basic factor flexibly. Finally, a EWG′s early warning information for guidance mission case is demonstrated.
Abstract: Mainlobe jamming is an essential threat to radars. Resource management collaborating multiple radars is an effective strategy to counter such threats. In this paper, a reinforcement learning-based technique of dynamically selecting multiple radar active and passive work modes is proposed to improve the overall performance of multi-target tracking under mainlobe jamming. The active measurement and passive localization models in jamming conditions are presented. An objective function to minimize tracking error is designed by utilizing the opposite correlation between precision and jamming intensity of the two work modes. Finally, a reinforcement learning agent employing the proximal policy optimization algorithm is used to select the radars′ work modes. The remaining variables of multi-radar dwell time are then optimized as a convex optimization problem. Simulation results demonstrate that, compared to per-determined work mode selection strategies, the proposed approach improves the tracking performance of the radar network in jamming environments, thereby improving the anti-jamming capability.
Abstract: Distributed detection is a hot topic in the radar field. Signal fusion-based detection generally outperforms data fusion based detection, but the communication cost is often huge. In order to tackle this problem, a data compression algorithm for distributed non-coherent target detection based on signal fusion is presented in this paper. In the proposed algorithm, signal fusion with parallelized computation is employed to realize the decoupling of observations from different radars, and censored detection is used to eliminate locally unpowerful noise from transmitting, and then censored observations are compressed by requantization processing. Detection performance of the proposed algorithm is capable of approaching a signal fusion-based algorithm, but only needs a low communication cost like a data fusion-based detection. Numerical simulation results with four distributed radars indicate that compared with signal-fusion based detection algorithms, the communication bandwidth of the proposed compression algorithm can be reduced to 0. 1??, whereas the signal-to-noise ratio loss is less than 0. 7 dB. Accordingly, the radar network structure design problem is then discussed for distributed radar to support different application scenarios.
Abstract: In the complex electromagnetic environment of modern warfare, the early warning and air defense combat system based on netted radars is an inevitable choice to counter threats posed by stealth combat aircraft, loitering munitions, drones, hypersonic missiles, and other new types of combat assets that form multi-dimensional and layered penetration threats. The collaborative architecture of a netted radar system is crucial for achieving a significant increase in system effectiveness. A design scheme for a collaborative system of netted radar based on cloud-edge-end architecture is proposed in the paper. A multi-station spatio-temporal synchronization method is introduced, featuring high-precision Beidou equipment as the time-frequency synchronization reference. A software-defined radar implementation scheme and a two-level control resource management system are designed. The collaboration modes and types of tasks that the system can support are elaborated upon, with the resource management mechanism detailed, which uses sub-tasks as the smallest granularity. For task-level and parameter-level collaborative tasks, the real-time remote closed-loop feedback control principle of the netted system is revealed. Finally, an introduction to the pre-plan design process of this system is provided.
Abstract: Affected by the increasingly complex target characteristics, electromagnetic environment and geographical environment, the detection effectiveness of single-unit radar is greatly constrained, and the radar network cooperative detection technology provides a technical mechanism to enhance the detection capability of single-unit and intra-system targets, anti-jamming capability and intelligence support capability. Radar network cooperative detection system can be divided into two categories: task level/ parameter level and signal level. For the task-level and parameter-level network cooperative detection system, in order to realize the main functions of radar cooperative operation, overall detection, regional confrontation and intelligence sharing within the network, the engineering design mainly accomplishes the functions of task planning, cooperative management and control, information fusion, performance evaluation, cooperative engagement command and control, and network communication, etc. , so as to realize the system empowerment for the single-unit and system. The signal-level distributed cooperative detection system mainly solves the problem of time, frequency and space synchronization, forms a dual/ multi-base signal cooperative system, realizes the signal-level gain of the receiving and sending phase reference system, and realizes the equivalent “big radar” performance.
Abstract: In adversarial scenario with multiple and dynamic targets, to match cooperative processing methods with the targets, environment and the resources of distributed multi-radar, a multi-level cooperative processing framework was designed. The framework includes four cooperative processing levels: signal level, feature level, point level and track level. Aiming at application, a multi-radar signal level joint detection model based on unified spatial grid was established. Time-space registration and multi-radar signal fusion were achieved by the model. A feature level distributed detection model was designed. It compressed transmission data for fusion detection. The cost-effectiveness of cooperative processing technique at different levels were comprehensive analysed. Adaptive selection principles for cooperative processing methods in typical application scenarios were provided. The effectiveness of the proposed technique was confirmed through simulation and typical experiment system. Results indicates that the technique can dynamically adapt to changes in targets and environments, also improve the efficiency of multi-radar cooperative detection.
Abstract: Utilizing existing electromagnetic signals in the environment, distributed passive synergy surveillance means zero-power silent surveillance of targets can be conducted. This significantly enhances radar′s low interception and anti-jamming capabilities, making it one of the key development directions in multi-radar synergy surveillance technology. Currently, passive synergy localization primarily faces challenges such as weak target echoes, unknown parameters of non-cooperative transmitters, and direct-path interference. A signal-level high-precision target localization method for distributed multistatic passive radars is proposed in this paper to address these issues. This method involves combining dual-channel signals received by multiple passive radars to establish a signal-level target position estimation problem, achieving joint direct-path interference suppression and high-precision estimation of the external transmitters and target positions, thus forming a zero-power silent synergy surveillance capability for distributed multistatic passive radars. Additionally, sequential and alternating iterative estimation strategies are used to reduce the high-dimensional estimation problems to multiple low-dimensional ones, lowering the computational complexity and enhancing the real-time localization capabilities. Simulation results indicate that compared to data-level localization, the proposed signal-level method demonstrates superior performance in low signal-to-noise ratio and direct-path interference environments. The proposed passive synergy localization method can be applied in scenarios such as UAV silent surveillance, anti-low-altitude, and anti-stealth targets, which can significantly enhance surveillance and strike capabilities against enemy targets.
Abstract: The radar jamming achieves multi-domain coverage of radar time, space and frequency, and has the ability to quickly follow the radar signal changes, so that the combat effectiveness of single radar under the condition of jamming is greatly compressed. Under the guidance of systematic operational thinking, using multi-radar networking is one of the effective ways to improve radar detection capability under complex jamming conditions. In this paper, based on the analysis of the anti-jamming technology of the radar interference, based on the multi-radar network detection, the relationship between dual/ multi-radar control, state and information interconnection is analyzed, and the design methods such as command and control relationship, spatio-temporal synchronous design and information interconnection are put forward. At the same time, based on the open RF system architecture, a dynamic configurable resource scheduling framework and process are proposed to support the performance improvement of multi-radar networking under the condition of interference.
Abstract: Most modern radars are installed on rotatable platforms, allowing their array orientations to be dynamically adjusted. However, current mainstream target assignment algorithms often assume that the radar array orientations are fixed, neglecting their flexible adjustment capabilities, thereby limiting the overall operational effectiveness of radar networks in complex battlefield environments. To address this issue, a joint target assignment and orientation planning algorithm has been proposed. Firstly, by extending the dimensions of the assignment matrix, the target-sensor assignment is refined to the level of array orientation. Secondly, by introducing new constraint conditions, it ensures that each radar selects only one array orientation at each moment. Finally, a genetic algorithm is designed based on the model characteristics to achieve efficient solution of the assignment problem. Simulations demonstrate that compared to traditional fixed-orientation methods, the proposed assignment method achieves higher target coverage and overlap coverage.
Abstract: This paper addresses the optimization of deployment strategies for distributed radar systems in time difference of arrival localization tasks, aiming to enhance both localization and surveillance performance. Existing research typically focuses solely on optimizing radar node positions while neglecting the coupling between node orientation and surveillance performance. This paper introduces a joint optimization strategy for node placement and orientation, establishing a framework that addresses both single-objective localization optimization and multi-objective optimization, effectively balancing localization and surveillance tasks. The complex coupled constraints and non-convex nature of these optimization problems make analytical solutions difficult. Therefore, the paper also proposes a region-constrained multi-objective particle swarm optimization (RC-MOPSO) algorithm to find the optimal deployment strategy. This algorithm ensures that particles satisfy the complex constraints throughout the iterative process by introducing regional constraints during initialization and updates. Simulation results demonstrate that the proposed strategy achieves an optimal balance between localization and surveillance performance, significantly outperforming random deployment schemes, and exhibiting strong robustness to errors in radiation source power estimation.
Abstract: In the modern information battlefields, compared with the traditional combat mode where radars make independent detection and guidance, the multi-radar networking for detection and early warning has an increasingly more obvious development trend. The radar networking poses a huge threat to the safety of penetrating aircraft. In the process of covering and penetrating formation operations by long-range support jamming aircraft, the survival probability of the penetrating aircraft is used as the objective function to establish the jamming resource allocation model under constraints through analyzing the operation mode of multi-aircraft cooperative jamming to netted radar, so as to ensure the safety of penetrating aircraft with the maximum effectiveness of limited jamming resources. The jamming cover in the whole process of penetration is analyzed emphatically, and the problem of optimal resource allocation scheme is solved by genetic algorithm. The simulation results show that the survival probability of penetrating aircraft is 96. 72?? under the cooperative cover of support jamming aircraft. The allocation results meet the requirements of penetration operations, and the reasonable allocation of jamming resources plays a significant role in giving full play to the cooperative engagement capability of long-range support jamming aircraft.
Abstract: Face to the trend of software defined radar, based on open reconstructible and multifunctional operational requirements of digital array system, an universal design method for radar online reconstruction display software is proposed in this paper, which can efficiently complete the online reconstruction task of various functions of radar systems. Adopted a layered architecture model, designed an overall architecture from platform layer to application layer, applied service-oriented design thinking, integrated various functions into software framework with the form of plugins. Designed a configurable array reconstruction method that can adapt to custom configurations of any array structure. A design scheme of process reconstruction display software is proposed, which achieved online upgrading of information processing software after process redefinition. An efficient and natural human-machine interface is provided through human-machine interaction methods such as information visualization and design aesthetics. The design proposed in this paper has been officially applied in multiple radars, meeting the requirements of flexible system reconstruction and possessing high practical value.
Abstract: An omnidirectional incident electromagnetic environment was constructed, so that the polarization angle of the incident electromagnetic wave was within the range of [0,π/2], the incident angle was within the range of [0,2π], and the azimuth angle was randomly distributed within the range of [0,π/2]. The incident points of the electromagnetic wave are randomly distributed on a unit sphere centered on the cable. We focused on studying the similarities and differences between the Agrawal model and the Vance model in solving the field line coupling problem, and analyzed the effects of parameters such as cable height, length, radius, and termination resistance on the field line coupling results. The results show that the response waveforms of the Agrawal model and the Vance model to omnidirectional electromagnetic waves are generally consistent, but there is a certain deviation in the response amplitude. This is mainly due to the presence of a lumped source caused by the vertical electric field in the Agrawal model. When the lumped source is ignored, the two models can obtain the same response results. The response current on the cable increases with the height, length, and radius of the cable above the ground. The peak value of the response current of different terminal resistors decreases with the increase of terminal load.
Abstract: When the receiving lobe is tested in a multi-function unit-level digital array system, it is found that there is a noise drum packet about 10dB near the normal. The phenomenon of noise sweeping lies that the noise drum packet disappears when the beam points from one degree to two degrees away from the normal direction. In this paper, based on the basic model of cascaded noise figure of receiver, the noise figure formula of multi-channel input receiving system is derived, and the source of additional noise injection inside the receiver and its effect on the system are analyzed and mathematically modeled, the concept of optimization factor of additional noise scanning angle is defined, and the phenomenon of noise sweep is explained reasonably. Furthermore, according to the mathematical model, a variety of solutions are proposed, and the advantages and disadvantages of various schemes under the existing conditions are analyzed, and finally the measures to reduce the injection noise power are selected. The practice shows that the solution based on this measure is effective. The mechanism analysis, mathematical model and solution in this article can guide the follow-up products and have high reference value for practical engineering applications.
Abstract: A design of ultrawideband and low-profile antenna is introduced in this paper. The proposed antenna is consists of a bending dipole, two parasitic shorted walls, a shorted metal cylinder, a coaxial cable, and a metal ground. This paper gives the design process of the proposed antenna, which illustrates the effect of each structure on the antenna performances. By using the parasitic shorted walls, the current distribution on the arms of the dipole is reduced which reduces the influence of metal ground on the performance of the proposed antenna, and then the low-profile performance is realized. In addition, the radiation patterns of higher band are improved by bending the middle of the dipole. Consequently, the proposed antenna has an overall size of 750 mm×450 mm×295 mm. The profile of the proposed antenna is only 0. 09λ,where λ is the free-space wavelength at the lowest frequency. To illustrate the validity of antenna design, the antenna model is fabricated. This paper gives the measured and simulated results of antenna VSWR and gain. Good agreement between the measured and simulated results is observed. The impedance bandwidth for VSWR<2. 2 can cover the band of 96 MHz-500 MHz(135. 57??). In addition, in the working band, the radiation patterns of the proposed antenna are unidirectional, and the measured results are in good agreement with the simulated ones.
Abstract: The anti-impact design is an important part of the structural design of the shipborne radar. The commonly used numerical simulation methods in the impact resistance analysis are introduced, and the difference in efficiency and application scenarios among these methods is analyzed, providing a basis for the selection of simulation methods. A finite element model for a shipborne radar is created. To illustrate the difference in analysis results generated by different simulation methods, the dynamic design method (DDAM) and time-domain analysis method are applied to the analysis of impact resistance simulation separately, and the simulation results of the two methods are compared. The analysis results show that the stress distribution and the weak region of structure obtained by the two methods are basically the same with a higher calculation efficiency of DDAM. However, due to the conservative nature of the DDAM and overlooking of the dense low frequency band of the the modal problem, the calculated value of the stress becomes larger. So the time-domain analysis method is recommended to the analysis of impact resistance simulation for the shipborne radar.
Abstract: Wafer level packaging (WLP) technology can significantly compress the volume and weight of the front-end transceiver module, realizing the miniaturization of active phased array radar. However, it also brings great challenges, such as heat management, channel isolation, signal cross-talk and adaptability of repairing and testing. Due to the introduction of more process steps and complex package architecture, how to test wafer level packaging modules to ensure yield and reduce testing costs has become an important technical issue. In this paper, the wafer level heterogeneous integration technology in millimeter-wave is summarized. Besides, the testing requirements and technical challenges, along with some integration solutions and testing process of typical products are deeply discussed. The existing key technologies are sorted out from three aspects: wafer level testing with probe station, socket testing and over the air (OTA) testing. It can provide some valuable references for the construction of radio frequency wafer level 3D packaging modules.
Abstract: According to the basic theory of electromagnetic vortex wave, the properties of electromagnetic vortex waves are simulated and analyzed. Based on the uniform circular array model, the aliasing characteristics of the square Bessel function at the pitch Angle are verified. The principles and properties of linear Doppler, rotary Doppler and micro-Doppler are compared to show the advantages and disadvantages of vortex detection. The research progress of electromagnetic vortex wave Doppler detection in recent years is summarized, and the detection ability is verified by simulation. At the same time, the key problems in rotary Doppler and micro-Doppler detection are summarized, and the direction of further research is pointed out.
Abstract: Feature detection is an effective way to improve the detection of small sea-surface targets. Aiming at the problems of low detection probability of low-dimensional features and difficult control of high-dimensional feature false alarms, a high-dimensional feature detection method based on random forest with controllable false alarms is proposed in this paper. First, multi-dimensional features are extracted from multiple domains of time domain, frequency domain, and time-frequency domain. The detection problem is converted into a two-class classification problem in high-dimensional feature space. Second, two types of balanced training samples including sea clutter and target echo are obtained by simulating returns with target. Third, random forest algorithm is introduced into high-dimensional feature space, and function expression of the splitting factor and the false alarm rate is established to obtain the control region of false alarm. Finally, it is verified by the IPIX measured data that the proposed detector has a certain performance improvement and meets the requirements of real radar with constant false alarm detection.
Abstract: Jamming is one of the most important challenges airborne radar faces in the battle use, and so the anti-jamming capability becomes a key parameter used to evaluate the performance of airborne radar. First, the jamming environment that airborne radar encounters is introduced in this paper, then anti-jamming mind and advantages of anti-jamming strategy based on jamming environment are described. Further principles and implementations of some frequently-used anti-jamming methods are presented. Specially, recently focused anti-jamming techniques with polarimetry and with multistatic radar collaboration aimed at main-lobe jamming suppression are detailed. Finally, due to the progress of the jamming technique, future development tendency on the anti-jamming technique is analyzed.
Abstract: The cognitive radar architecture contributes to enhancing the intelligence of radar anti-jamming technology. Addressing the issue of radar perception of electromagnetic interference in the field of cognitive anti-jamming technology, a multi-node jamming modulation type recognition method based on deep learning is proposed. This method targets various nodes in radar signal processing, such as digital beamforming, adaptive sidelobe cancellation, before and after pulse compression, and post-moving target detection. The time-frequency plane and range-Doppler plane of multiple nodes are used as joint feature extraction objects for jamming signals. A deep learning-based multi-node jamming recognition strategy model is established to improve jamming recognition accuracy in various scenarios. To enhance the extraction capability of jamming features and the training efficiency of the network, the deep learning algorithm for jamming recognition incorporates attention mechanisms and residual networks into the convolutional neural network. This establishes an interference type recognition network structure for multi-node strategies, achieving recognition of various jamming types in different scenarios. Simulation results show that in a single jamming scenario, the proposed algorithm achieves a jamming recognition accuracy of up to 92?? at a jamming-to-noise ratio (JNR) of 14 dB. In multiple jamming scenarios, the proposed algorithm, supported by different node strategies, achieves an accuracy of up to 90%.
Abstract: The mainlobe deceptive jamming has the same angle as the real target scene, and the two are highly similar in multiple domains, which seriously reducing the detection and judgment capabilities of the synthetic aperture radar system for real targets. To address this issue and ensure effective suppression of mainlobe deceptive jamming, a real-time and fast processing anti-mainlobe deceptive jamming algorithm is proposed in this paper. First, an echo recovery framework based on azimuth phase coding is proposed and the framework can group the raw echo data. Secondly, a fast algorithm for modular processing is proposed to speed up the processing efficiency of the proposed method. Finally, the effectiveness and feasibility performance of the proposed method are verified through point target and distributed targets simulation experiments. By comparing with the traditional mainlobe deceptive jamming method, the proposed method can not only reduce the computational complexity, but also reduce the occupation of system resources.
Abstract: With the development and performance improvement of anti-jamming technology for anti-ship missile, the traditional on-platform shipboard jamming technology has not been sufficient to fully resist various naval war threats, therefore as an off-platform jamming method with networking capabilities, outboard active decoy has attracted much attention from navies of various countries. Firstly, the jamming mechanism and working characteristics of outboard active decoy are introduced, and the jamming strategy of using outboard active decoys in the ship defense system is analyzed in this paper, and the effectiveness of outboard active decoy is demonstrated too. Then, on this basis, the developments and technical characteristics of foreign outboard active decoy equipment are clarified. Finally, the countermeasures that can be adopted are analyzed for the anti-outboard interference measures of the new anti-ship missile seeker. The research content gives a comprehensive introduction for the outboard active decoy and its countermeasures, which can provide support for the subsequent design of outboard jamming products and anti-jamming technology of seeker.
Abstract: In military and civilian fields such as electronic warfare and wireless network security, specific emitter identification (SEI) has extremely high application value. The traditional methods are mainly based on manual feature extraction, which rely on prior knowledge and have poor generalization. Deep learning methods mostly use images containing two-dimensional information as input, which is easy to miss key information. In order to solve the above problems, a solution method using the afterglow map of the digital spectrum as the input of the deep learning model is proposed, so as to realize the SEI task. Firstly, an emitter signal detection and data acquisition system are built to obtain the afterglow map of the digital spectrum for the Wi-Fi emitter signal, and the first SEI dataset based on the afterglow map of the digital spectrum is established. Secondly, the problem of signal recognition is transformed into the problem of target detection by using the feature that the image contains more information. Finally, experimental verification is performed on the Wi-Fi emitter identification dataset (WFEID). Experimental results show that the P, R, F1 and mAP of YOLOv5s can reach more than 87. 5% on WFEID, which proves the effectiveness of the method using the afterglow map of the digital spectrum as the input of deep learning model in tasks of specific emitter identification.
Abstract: Firstly, the key parameters of each subsystem in the radar system are introduced and the constraints between the parameters as the constraint condition for radar optimization are analyzed. Secondly, the advantages and disadvantages of current typical multi-objective optimization algorithms are compared and their different application fields are analyzed. Thirdly, the intelligent optimization technologies that have been applied to radar design are classified and introduced from different perspectives of radar waveform design, antenna design, transmitter and so on. Finally, the future development trend of the intelligentization of radar is prospected. It is hoped that the summary analysis of this article can provide a reference for the intelligent design of radar in the future.
Abstract: Collaborative R&D platform on which processes,tools,data and knowledge were integrated was built through analyzing radar R&D problems.Unified design environment,unified process system,unified data space that composed radar R&D system were described.Three-tier structure of radar R&D platform was present.Management platform on collaborative tier provides the ability of task transition across organization and discipline.Design platform on application tier integrates knowledge and tool.Data platform on data tie...
Abstract: Radar has to deal with complex and changeable jamming scenarios in the process of work, and it is difficult to exhaust anti-jamming approaches. In the face of these confrontation scenarios, the artificial anti- jamming flow and suppression strategy cannot be guaranteed due to the limited experience and knowledge of experts. Based on the application requirements of radar antijamming, this paper introduces reinforcement learning method and proposes an intelligent anti-jamming method based on reinforcement learning model. Two typical reinforcement learning algorithms, Q-learning and Sarsa, are respectively used to calculate and iterate the value function in the anti-interference model, so that the anti-interference strategy has the function of self-updating and optimization. Simulation results show that the reinforcement learning algorithm can converge and optimize the anti-jamming strategy. Compared with the traditional anti-jamming design method, the intelligence of radar anti-jamming is improved effectively.
Abstract: The anti-jamming ability of radar is directly associated with winning or not in war. Combined with the developing direction of electronic war and the existing problem of anti-jamming in radar system, the demand in anti-jamming design of modern radar system is analysed. Firstly, based on the anti-jamming source reconnaissance and analysis, as well as the targets detection and track and adaptive anti-jamming, and self-jamming indexes which are used to assess the fighting ability of radar is constructed. Secondly, the demand of anti-jamming design is proposed in self-adaption closed-loop, integrated compatibility and big data accumulation. Lastly, the particle design is required by comparing multiple testing results in out-field.
Abstract: In computational electromagnetic field,the moment method based on surface integral equations for analysis of electromagnetic scattering by 3-D homogenous dielectric and PEC objects is a hot topic all through.In this paper,the EFIE integral equation is built on the surface and PMCHW integral equations is constructed based on the surface of homogenous dielectric object.Combined with adaptively modified characteristic basis function method(AMCBFM) that is based on dividing the object geometry into distinct blo...
Abstract: The sorties determination principle is discussed for narrowband coherent radar targets with non-rigid-structure based on a long coherent integration time in this paper.Firstly a novel signal model is proposed and some new concepts are put forward,such as common rotation Doppler,radial Doppler,chirp Doppler.And then it is pointed out that the initial frequency of target time-frequency distribution is decided by the sum of common rotation Doppler and radial Doppler,the trend is decided by chirp Doppler.Accord...
Abstract: To meet the requirement of the deep space exploration of China, the planet radar equipment development is suggested to enhance the deep space exploration system based on its recent working mode. The ground-based deep space expoloration network of USA adopts deep space telemetry, track and command network, very long baseline array network and ground-based planet radar. By calling different equipments, different working modes can be formed, and all equipemnts are used with high efficiency. Modes of deep space exploration of USA are investigated and constituting programming of ground-based planet radar and research of key techniques are suggested. The purpose is to provide support and reference for China's deep space exploration in the future.
Abstract: Based on the pulse load characteristics of the transmitting unit, the equivalent circuit and the mathematical model of the transmitting unit are established. Four states of the transmitting unit power supply system are studied by the state space segmentation method. Based on the system states equations, the theoretical calculation formula of the voltage drop with the transmitting unit is derived. The main factors of the voltage drop are also obtained. In order to satisfy the constraint of the voltage drop, the accurate and approximate formulas of the capacitance for energy storage are derived. The achievements are verified by the simulation. The proposed propositions and inferences constitute the basic theory of the power supply system design of the transmitting unit. The conclusions lay a theoretical foundation for the design of power supply system of phased array radar with long pulse width, which has great engineering application value.
Abstract: The detection of sea surface unmanned aerial vehicles (UAVs) belongs to the problem of small target detection in the background of sea clutter due to weak echoes, and joint multi-feature detection is an effective way to solve such problems. Aiming at the existing time-frequency (TF) tri-feature detection method, which has too much computational complexity in the feature extraction stage and is difficult to realize real-time detection, this paper proposes a fast TF-map-based multi-feature detection method for sea surface UAVs. First, the segmented FFT is performed on the radar complex echo data, and the computed Doppler amplitude spectrum is aligned and spliced along the Doppler dimension so as to construct a fast time-frequency map. Second, the fast TF map is normalized to achieve clutter suppression and enhancement of the target echoes, and three kinds of time-frequency features are extracted based on the normalized fast TF map. Third, the fast convex hull learning algorithm is utilized to train the decision judgement region under the given false alarm probability. Finally, the effectiveness of the proposed method is validated and analyzed by the measured UAV data.
Information
Search
External Links
