Radar Detection Research Articles

Harmonic Motion Tracing Patterns in a Rotating Field

Abstract: In this study, we present a radar detection system for real-time object localization based on ultrasonic sensor technology. The system combines ultrasonic sensors, a servo motor, and an Arduino microcontroller to send ultrasonic waves, detect their echoes, and compute distances with high accuracy. This information is processed to generate a spatial map of the environment around it, allowing for precise object detection and localization in real time. The system works by utilizing the servo motor to spin the ultrasonic sensor, taking distance readings over an array of angles. The data is processed and presented, giving a real-time visualization of the objects found in the surroundings. This method guarantees high precision with simplicity and affordability. The flexibility of the system to various environmental conditions makes it a perfect solution for a variety of applications such as robotics, security systems, surveillance, obstacle detection, and industrial automation. One of the major benefits of this system is its cost-effectiveness and ease of construction, making it affordable for hobbyists, researchers, and industry experts. The modular design also guarantees flexibility, making it possible to customize it for particular applications or integrate it with sophisticated systems. Our study emphasizes the potential of ultrasonic sensor technology in object detection systems, opening doors to novel applications in automation, navigation, and safety systems.

Analysis of Different Noise Reduction Effects of Ground Penetrating Radar Image of Cavity Behind Tunnel Primary Support Based on Singular Value Decomposition and Wavelet Transform

The cavity behind the lining structure is a typical disease in tunnel engineering. Cavity seriously affects the interaction between lining and surrounding rock, resulting in uneven bearing of lining structure and stress concentration, which can easily induce lining concrete cracking, water leakage and other diseases. Accurate identification of lining structure cavities is the key to ensure the normal operation of the tunnel. However, the ground penetrating radar detection images of lining cavities often contain interference signals such as background noise, which seriously affects the accuracy and clarity of cavity detection. The application effects of wavelet transform and singular value decomposition in image denoising and resolution of tunnel lining cavity ground penetrating radar are studied. Under this background, the model test of regular and irregular cavity detection behind tunnel lining is carried out, in which the irregular cavity is located in the surrounding rock environment of filling soil to simulate the real situation of tunnel. The measured images of lining cavity under different working conditions are obtained, and the image denoising analysis is carried out. The results show that singular value decomposition can effectively suppress noise. The ground penetrating radar image after singular value decomposition denoising is clearer, and the image resolution is effectively improved, thus realizing the accurate identification of cavity diseases behind the primary support of the tunnel

A Self-Supervised Feature Point Detection Method for ISAR Images of Space Targets

Feature point detection in inverse synthetic aperture radar (ISAR) images of space targets is the foundation for tasks such as analyzing space target motion intent and predicting on-orbit status. Traditional feature point detection methods perform poorly when confronted with the low texture and uneven brightness characteristics of ISAR images. Due to the nonlinear mapping capabilities, neural networks can effectively learn features from ISAR images of space targets, providing new ideas for feature point detection. However, the scarcity of labeled ISAR image data for space targets presents a challenge for research. To address the issue, this paper introduces a self-supervised feature point detection method (SFPD), which can accurately detect the positions of feature points in ISAR images of space targets without true feature point positions during the training process. Firstly, this paper simulates an ISAR primitive dataset and uses it to train the proposed basic feature point detection model. Subsequently, the basic feature point detection model and affine transformation are utilized to label pseudo-ground truth for ISAR images of space targets. Eventually, the labeled ISAR image dataset is used to train SFPD. Therefore, SFPD can be trained without requiring ground truth for the ISAR image dataset. The experiments demonstrate that SFPD has better performance in feature point detection and feature point matching than usual algorithms.

Dual Function Radar and Communication Signal Design with Combined Waveform Selection and Pulse Repetition Interval Agility

The traditional probe–pass integration system embeds communication information into a radar waveform, which leads to a high level of waveform autocorrelation sidelobes and a poor false symbol rate at low signal-to-noise ratios. This article proposes a three-dimensional indexed modulation-based design method for probe–pass integration waveforms. This method realises communication information modulation and demodulation by simultaneously indexing orthogonal waveform selection, transmitting pulse PRI changes and carrier frequency changes in three dimensions, and applying compressed perception technology to solve the problems of PRI shortcuts and carrier frequency, resulting in a velocity term in the received waveform that cannot be accumulated by phase reference to realise velocity super-resolution. Finally, the radar detection performance and communication performance are simulated and analysed, and the simulation results reveal that the method proposed in this paper can not only satisfy the radar detection performance requirements but also achieve a lower unsigned rate on the basis of an improved communication rate.

Sea Clutter Suppression Method Based on Ocean Dynamics Using the WRF Model

Sea clutter introduces a significant amount of non-target reflections in the echo signals received by radar, complicating target detection and identification. To address the challenge of existing filter parameters being unable to adapt in real-time to the characteristics of sea clutter, this paper integrates ocean numerical models into the sea clutter spectrum estimation. By adjusting filter parameters based on the spectral characteristics of sea clutter, the accurate suppression of sea clutter is achieved. In this paper, the Weather Research and Forecasting (WRF) model is employed to simulate the ocean dynamic parameters within the radar detection area. Hydrological data are utilized to calibrate the parameterization scheme of the WRF model. Based on the simulated ocean dynamic parameters, empirical formulas are used to calculate the sea clutter spectrum. The filter coefficients are updated in real-time using the sea clutter spectral parameters, enabling precise suppression of sea clutter. The suppression algorithm is validated using X-band radar-measured sea clutter data, demonstrating an improvement factor of 17.22 after sea clutter suppression.

Programmable beam steering and quasi-continuous phase shift on a 2-bit terahertz coding metasurface with HEMT-switched multimodal modulation.

Terahertz reconfigurable intelligent surfaces (RIS) stand out from conventional phased arrays thanks to their unique electromagnetic properties and intelligent interconnect paradigms. They are a vital technology for terahertz wireless communication and radar detection systems. Compared with 1-bit coding metasurfaces, 2-bit coding metasurfaces offer significant advantages such as single beam steering and reduced quantization errors. Electrically controlled switchable coding metasurfaces have been restricted by the switch performance and integration technology, limiting reported devices to 1-bit coding. Additionally, metasurfaces that offer quasi-continuous phase modulation across a 2π range have garnered extensive attention for their higher phase shift precision and regulation freedom. This paper proposes a 2-bit multimodal THz quasi-continuous phase shift coding metasurface based on asymmetrically configured high electron mobility transistor (HEMT)-dipoles. The meta-device consists of two asymmetrically combined HEMT-dipole resonant structures, wherein the versatile density variations of two-dimensional electron gas (2DEG) introduce subtly local-field modulation under different external voltage combinations, rendering the quasi-continuous phase shift of 0° to 350° at 0.376 THz with a minimum incremental step of 6°. Moreover, selecting optimal 2-bit coding states within the quasi-continuous phase shift loop constructed different array phase gradients based on Snell's law, enabling real-time beam steering from 21° to 48° within the 0.365-0.385 THz frequency range. The simulation results align closely with the experimental findings, marking the first achievement of real-time programmable phase shift control and 2-bit beam steering using electrically controlled switches in the terahertz domain. This research provides a practical approach for real-time quasi-optical continuous phase modulation control and programmable single-beam electronic steering, with promising applications in terahertz wireless communication, radar detecting, and computational imaging, among other fields.

Application of Near-Far Field Conversion to Measurement of Scattering on Bessel Vortex Electromagnetic Wave

The measurement and analysis of the interaction between Bessel vortex electromagnetic (EM) and several standard targets are presented in this paper. With the aid of the angular spectrum expansion (ASE) method and physics optics (PO) theorem, scattering results on the plates (metal and dielectric) and a sphere could be derived. Furthermore, plane near-field scanning and near-far field conversion methods were implemented to compare the theoretical radar cross section (RCS). In the experiment, the quasi Bessel vortex wave was generated by a holographic metasurface antenna, and the whole measurement was performed in an anechoic chamber. The results of both the theory and measurement show that the scattered fields of the plate and sphere still had characteristics of the vortex EM wave, and the scientificity and accuracy of the measured RCS were verified. Our work involved a vortex scattering experiment in the microwave frequency band, which provides strong support for the application of vortex waves in radar detection and target recognition.

Research on Autonomous Car Sensor Fusion Methods

Autonomous vehicles ( AVs ) represent a significant technological advance poised to transform transportation by enhancing road safety, reducing traffic congestion, and reducing human error. Performance is largely a function of AVs ' ability to accurately interpret the environment, which is achieved by using a complicated method of cameras. Even though all of these cameras, like LiDAR, radar, cameras, and radar detectors, have advantages and disadvantages, no one system is capable of properly handling all driving conditions. To overcome these limitations, sensor fusion combines data from various cameras to create a detailed, reliable belief structure. This statement examines various sensor fusion techniques, identifies their limitations, and suggests a site for increased communication. This page combines probabilistic models and machine learning strategies, increasing the car's object detection, tracking, and choice-making abilities. Through style and genuine-world tests, the proposed model shows major improvements in sensor reliability, especially in adverse conditions like as bad weather or reduced visibility.

Advanced Scattering Analysis of Targets Under Plane Waves and Electromagnetic Vortex Waves for Stealth Applications

This study investigates the scattering characteristics of typical metallic targets under the influence of electromagnetic vortex waves, with a focus on Radar Cross Section (RCS) and Orbital Angular Momentum Radar Cross Section (ORCS). Using the physical optics approximation, the induced current density on the target surface was calculated, and the backscattered field was derived. The comparative analysis highlights the advantages of electromagnetic vortex waves over plane waves in stealth applications, with an in-depth examination of the impact of different OAM modes on power distribution and flat plate scattering characteristics. The unique properties of electromagnetic vortex waves show promising applications in stealth radar and target detection. Furthermore, the study discusses the potential for using OAM waves in enhancing radar system performance, target identification, and electronic countermeasures. The ability of OAM waves to provide selective detection capabilities and reduce RCS under certain conditions makes them particularly valuable for military stealth applications. The combination of MIMO technology with OAM waves is also explored as a means to further improve detection capabilities and flexibility. The findings suggest that electromagnetic vortex waves have a broad range of applications beyond stealth, including radar sensing, imaging, and rotational Doppler detection, thereby opening new avenues for advanced radar technologies

Narrow Linewidth All-Optical Microwave Oscillator Based on Torsional Radial Acoustic Modes of Single-Mode Fiber.

A Hz level narrow linewidth all-optical microwave oscillator based on the torsional radial acoustic modes (TR2,m) of a single-mode fiber (SMF) is proposed and validated. The all-optical microwave oscillator consists of a 20 km SMF main ring cavity and a 5 km SMF sub ring cavity. The main ring cavity provides forward stimulated Brillouin scattering gain and utilizes a nonlinear polarization rotation effect to achieve TR2,7 mode locking. By combining the sub ring cavity with the main ring cavity and utilizing the Vernier effect, the TR2,7 mode microwave photonic single longitudinal mode (SLM) output can be ensured. Meanwhile, the 6.281 Hz narrow linewidth of the TR2,7 mode is achieved by reducing the intrinsic linewidth of the passive resonant cavity. The acoustic mode suppression ratio and side mode suppression ratio of the TR2,7 mode were 43 dB and 54 dB, respectively. The power and frequency fluctuations of within 40 min were approximately ±0.49 dB and ±0.187 kHz, indicating good stability. At a frequency offset of 10 kHz, the TR2,7 mode had a low phase noise value of -110 dBc/Hz. This solution can be used in various fields, such as high-precision radar detection, long-distance optical communication, and high-performance fiber optic sensing.

A Novel Full‐Band Microwave Absorber Based on Scattering Enhanced Prism‐Honeycomb Nested Structure

AbstractWith advancements in radar detection technology, electromagnetic stealth has garnered significant attention in military applications. Traditional electromagnetic absorbers typically focus on tuning electromagnetic parameters; however, they are often limited by material constraints, resulting in effective absorption only within narrow frequency bands. This work presents a novel prism‐honeycomb nested microwave absorbing structure, inspired by the scattering phenomenon of light waves in a prism, which utilizes an enhanced scattering effect. The varying impedances of electromagnetic waves (EMWs) in different media lead to transmission and reflection that adhere to Snell's law at the interfaces. To optimize the scattering effect, the inner prism is filled with a high transmittance material, while the outer honeycomb structure incorporates a material with high dielectric loss. Consequently, electromagnetic waves experience significant attenuation within the unit. Despite a thickness of only 7 mm, this structure achieves over 90% EMW absorption across a broad frequency range of 1–18 GHz. Additionally, the honeycomb structure exhibits excellent mechanical load‐bearing capacity. The nesting of the prism further enhances support points, resulting in a compressive strength of 16.4 MPa. This innovative design not only facilitates full‐band absorption but also provides high mechanical load‐bearing capabilities, offering valuable insights for applications in electromagnetic stealth and camouflage.

Game Theoretic Power Allocation and Antenna Selection for Target Detection in Hybrid Active and Passive MIMO Radar

Game Theoretic Power Allocation and Antenna Selection for Target Detection in Hybrid Active and Passive MIMO Radar

Practice and theoretical analysis of ground penetrating radar in voids detection of urban underground pipe-jacking

Practice and theoretical analysis of ground penetrating radar in voids detection of urban underground pipe-jacking

Contactless High Dynamic-Range Blood Pressure Estimation by Pulse Morphological Features Based on Accurate Doppler Radar Detection

Contactless High Dynamic-Range Blood Pressure Estimation by Pulse Morphological Features Based on Accurate Doppler Radar Detection

HIGH-FREQUENCY METHODS FOR CALCULATING SCATTERING CHARACTERISTICS OF GROUND-BASED RADAR OBJECTS OF COMPLEX SHAPE

One of the ways to obtain information on the scattering characteristics of ground-based weapons and military equipment in the radar range is mathematical modeling. Mathematical modeling, unlike full-scale and physical experiments, requires significantly less material, organizational and time costs. Radar detection of ground objects is an important component of modern intelligence, surveillance and security systems. They are used to monitor military facilities, vehicles, equipment and personnel on the ground. The main types of radar detection equipment for ground objects are: ground-based radar stations (hereinafter referred to as radars), mobile and portable radars, as well as radar systems installed on board manned or unmanned aircraft.One of the main directions of development of modern offensive weapons and military equipment is the creation of samples of ground (armored) military equipment possessing small values of effective scattering surface. Reduction of radar conspicuity of ground-based military equipment samples is achieved by applying special smoothing forms and covering local areas of the strongest secondary radiation associated with geometro-optical reflection and with scattering on surface fractures with radio-absorbing materials. These measures not only noticeably reduce the energy level of the reflected signal, but also lead to significant changes in other, in particular, polarization characteristics of the target and thus complicate the effective solution of not only detection but also recognition tasks.The article evaluates modern high-frequency methods for calculating the secondary radiation characteristics of complex ground-based radar objects of complex shape by mathematical modeling. The calculation of the scattering characteristics of objects with surface breaks is carried out by preliminary dividing the surface into a smooth part and edge areas of the surface. The considered methods make it possible to evaluate the characteristics of secondary radiation of both a perfectly conductive object located near the boundary of a homogeneous half-space and a ground-based radar object with an imperfectly reflective surface.The application of the presented calculation methods can contribute to obtaining a priori information about the scattering characteristics of ground-based radar objects of complex shape, taking into account such complicating factors as the intra-system interaction “ground object - ground surface”, the presence of radio-absorbing coatings and their complex effect.

DESIGN AND DEVELOPMENT OF A STEALTH UNIC FOR SILENT OPERATION WITH ESP32-BASED AUTONOMOUS CONTROL

This research aims to design and build a stealth kamikaze drone for Silent Operation, named Unic, with an autonomous control system. In a modern context that increasingly emphasizes military technology, the existence of drones capable of conducting precision attacks without detection has become essential. This drone is designed to target enemy objectives with the aim of effectively detonating targets without being detected. The design process includes the selection of key components using ESP32, the development of autonomous navigation algorithms, and the integration of secure communication systems. In terms of stealth, the drone is equipped with silent-designed brushless motors that produce noise levels below 25 dB to reduce the likelihood of being heard from a distance. This research also includes performance testing of the drone in simulated scenarios, focusing on maneuverability, navigation accuracy, and stealth capabilities to avoid radar detection and other surveillance systems. Test results show that Unic can perform autonomous flights with high accuracy, optimizing stealth to evade radar and sound detection. These findings are expected to contribute to the development of military drone technology and enhance the effectiveness of national defense strategies. Future research will focus on improving sensor capabilities and anti-jamming systems to support operations in complex environments.

Preface: 5th International Conference on Artificial Intelligence and Engineering Applications (AIEA 2024)

2024 the 5th International Conference on Artificial Intelligence and Engineering Applications (AIEA 2024) was held in Guilin, China during November 16-17, 2024. AIEA 2024 is a platform for presenting excellent results and new challenges facing the field of the artificial intelligence and engineering applications, especially in the field of unmanned vehicles and aircraft, infrared identification, radar detection and so on. It brings together experts from industry, governments and academia, experienced in engineering, design and research. We appreciate that if you disseminate this flyer to your friends, colleagues, disciples and others who might interests to AIEA Conference Series. The conference received 91 manuscripts, by submitting a paper to AIEA, the authors agree to the review process and understand that papers undergo a peer-review process. Manuscripts will be reviewed by appropriately qualified experts in the field selected by the Conference Committee, who will give detailed comments and-if the submission gets accepted-the authors submit a revised version that takes into account this feedback. All papers are reviewed using a double-blind review process: authors declare their names and affiliations in the manuscript for the reviewers to see, but reviewers do not know each other's identities, nor do the authors receive information about who has reviewed their manuscript. The Committees of AIEA 2024 invest great efforts in reviewing the papers submitted to the conference and organizing the sessions to enable the participants to gain maximum benefit. With our warmest regards, Kaisen Li, Truman Pan Conference Organizing Committees

Method of determining the coordinates of a low altitude object under the conditions of using several radio signals.

Currently, in large cities, there is a steady tendency to increase the spatial density of telecommunication systems. The saturation of the radio spectrum with analog and digital systems used to solve the problems of radio communication and television allows to improve the technologies of semi-active radar detection and determination of the coordinates of a low-altitude object on their basis. Conducting radar surveillance using non-radar radar transmitters is often called semi-active radar using extraneous or parasitic radiation sources. The advantages of such systems are the minimization of deployment costs, low operating energy costs, low probability of malfunctioning, stealth of the fact of operation, environmental friendliness, and the absence of requirements for the allocation of radio frequency resources. Relatively high heights of antennas of communications and television transmitters with the existing radiated power create favorable conditions for detecting low-altitude objects. Digital signals of modern telecommunication systems have a spectrum width that provides acceptable resolution and accuracy of measuring the total distance and angular coordinates [20; 21]. In the general case, systems of this type are a multi-position system consisting of one or more radiation sources and one or more receiving positions spread in space [22; 23]. The paper gives a general description of the proposed method of determining the coordinates of an aerial object at low altitude under the conditions of propagation of several beams of radio signals. The method and its technical solution capable of determining the coordinates of an unauthorized low-altitude object under the conditions of the existence of several rays of radio signal propagation are defined, and the algorithm of its operation necessary for the technical implementation of the proposed method is presented. The paper considers options for determining the coordinates of aerial objects with different composition of primary coordinate measurements and the number of receiving points. The accuracy of determining the location of the object for multi-position radio systems of this type was evaluated under the conditions of the existence of several beams of radio signal propagation in the developed model, taking into account the number of received signals and their measurement errors.

Robust design of mismatched filters in echo truncation for inter‐pulse waveform diversity radar

AbstractRange sidelobe modulation is a primary issue that forbids application of inter‐pulse and intra‐coherent processing interval (coherent processing interval) waveform diversity in moving target indication or moving target detection radars. Previous research has adopted mismatched filters (MMFs) to reconstruct identical compressed outputs based on an ideal model. In practice however, echo truncation is inevitable due to transceiver isolation, significantly degrading the effectiveness of MMFs. In this paper, the design of MMFs under an echo‐truncated model to achieve a robust design is considered. Specifically, the authors extract the dominant scattering profile from the close‐range echo and incorporate it into the MMF design model. To judiciously combine the robust design with the ideal one, a segmented pulse compression scheme is proposed. Numerical results indicate that the proposed robust processing scheme can effectively reduce clutter leakage in both truncated and intact scenarios.

1-Bit Reconfigurable Transmitarray Antenna with Out-of-Band RCS Reduction

Stealth reconfigurable transmitarray antennas (RTAs) are essential components in wireless communication and radar detection systems. Therefore, in this study, we propose a 1-bit RTA with out-of-band radar cross-section (RCS) reduction. The antenna consists of an absorptive frequency selective transmission (AFST) layer and RTA layer separated by air. Specifically, the AFST layer achieves out-of-band RCS reduction and in-band transmission utilizing the first three resonant modes of a bent metallic strip with a centrally loaded resistor. Meanwhile, the RTA layer adopts a receiver–transmitter structure with an active receiving dipole and a passive orthogonal transmitting dipole. 1-bit phase shift is achieved by alternating two pin diodes integrated on the active dipole to reverse its current direction. To evaluate the proposed design, a 16 × 16-element prototype was designed, fabricated, and measured. For scattering, the bandwidth of 10 dB RCS reduction was about 52.5% and 43.8%, respectively. For radiation, the measured gain was 20.1 dBi at 7.5 GHz, corresponding to an aperture efficiency of 12.7%. The gain loss of beam scans to ±60° was about 5 dB in both two principal planes.