Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
50,979
result(s) for
"Radar systems"
Sort by:
Enhanced dual lane detection in automotive radar systems using harmonic coordinated beamforming of time-modulated arrays
This paper introduces an advanced beamforming methodology for time-modulated arrays by leveraging harmonic coordination. The proposed approach assigns complex beams to designated angular ranges and synthesizes distinct harmonic beams to achieve sophisticated beamforming. Furthermore, this study introduces two innovative structural models, namely the parallel and cascade structures, to amplify the degree of freedom for harmonics in the frequency domain. Through rigorous derivations and comprehensive simulations, the efficacy of the proposed methodology is demonstrated. The results reveal that the harmonic coordination approach outperforms conventional methods in synthesizing optimal beam patterns, thereby enhancing the efficacy of different detection states in automotive radar systems.
Journal Article
Generalized Radar Range Equation Applied to the Whole Field Region
Most terahertz (THz) radar systems can only work in the near-field region, because the THz source power is limited and the size of the target scattered near field is up to tens of kilometers. Such conditions will result in the conventional radar range equation being unsuitable. Therefore, the near-field radar cross section (RCS) formula is given according to the numerical simulation on different targets. By modifying the parameters in the near field, including the gain of radar antennas and the RCS of targets, the generalized radar range equation is proposed. The THz radar working efficiency in the whole range and the simulation of the near-field RCS simulation model were employed to validate its effectiveness. Through comparison with the radar range equation, it can be concluded that the calculation results of the proposed equation are smaller in the near field, and the outcomes in the far field are identical. The proposed generalized radar range equation can be applied to the whole radiation area including the near field and the far field. Furthermore, more complicated real targets are calculated according to the generalized radar range equation and it can be extended from the submillimeter wave band to a much wider band range. Finally, the near-field radar theory is established, which shows its potential application to the radar cross section estimation in the extremely high frequency and fine design of THz radar systems.
Journal Article
Beyond Fixed Waveforms: Adaptive Angle‐Dependent Design for Next‐Generation 3D Radar Systems
Traditional radar systems use fixed waveform parameters, degrading performance for targets at extreme angular positions. This study analyses angle‐dependent waveform design for 3D radar, dynamically adjusting parameters with target position. Modulation functions for bandwidth and pulse duration are introduced, and their effects on key performance metrics are evaluated. Mathematical analysis and simulations show marked gains in range resolution and estimation accuracy, with up to 75% improvement for high‐elevation targets. Results validate the theoretical benefits of this adaptive approach over fixed‐parameter waveforms, offering a practical enhancement for modern phased array radars engaging targets across diverse angular positions.
Journal Article
Design and performance evaluation of a mature FM/DAB/DVB-T multi-illuminator passive radar system
Passive radar (PR) systems use the target illumination by third-party transmitters, for example, from broadcast or cellular base stations, for target detection and localisation. Since PR does not use an own transmitter, it can be installed and operated at low cost and it is hard to detect and jam. These advantages and the increasing maturity of PR technology has led to growing interest in these systems over the last years. However, until now most PR systems have been rather experimental set-ups tailored to a single frequency band or implemented as laboratory test devices. This study in contrast describes the design, implementation and performance evaluation of a multi-band, multi-illuminator PR system developed at near-production stage. Starting out from a FM-broadcast-based approach, the step to DAB-based and DVB-T-based operation has already been made. As a result, a fully mobile FM/DAB/DVB-T multi-band PR system is now available, offering maximum flexibility for measurement campaigns with air, ground and sea targets. Experiments with a great variety of third-party transmitters and arbitrary transmitter-target-receiver geometries have been conducted. The design considerations and the resulting PR system concept are described, and the results of representative measurement campaigns with different types of ground and aerial targets are presented.
Journal Article
A Low-Complexity Hand Gesture Recognition Framework via Dual mmWave FMCW Radar System
In this paper, we propose a novel low-complexity hand gesture recognition framework via a multiple Frequency Modulation Continuous Wave (FMCW) radar-based sensing system. In this considered system, two radars are deployed distributively to acquire motion vectors from different observation perspectives. We first independently extract reflection points of the interested target from different radars by applying the proposed neighboring reflection points detection method after processing the traditional 2-dimensional Fast Fourier Transform (2D-FFT). The obtained sufficient corresponding information of detected reflection points, e.g., distances, velocities, and angle information, can be exploited to synthesize motion velocity vectors to achieve a high signal-to-noise ratio (SNR) performance, which does not require knowledge of the relative position of the two radars. Furthermore, we utilize a long short-term memory (LSTM) network as well as the synthesized motion velocity vectors to classify different gestures, which can achieve a significantly high accuracy of gesture recognition with a 1600-sample data set, e.g., 98.0%. The experimental results also illustrate the robustness of the proposed gesture recognition systems, e.g., changing the environment background and adding new gesture performers.
Journal Article
Polarimetric Calibration Technique for a Fully Polarimetric Entomological Radar Based on Antenna Rotation
For entomological radar, the polarization information of the target is usually used to estimate the biological parameters, such as orientation, body length, and mass, of the insect. Thus, the accuracy of polarization measurement directly affects the performance of the biological parameters’ estimation. The polarization measurement error is mainly caused by the imbalance of amplitude and phase between two polarization channels and the crosstalk of the dual-polarization antenna. In order to obtain the correct polarization information of the target, the polarimetric calibration of the entomological radar is required. This paper proposes a new polarimetric calibration technique based on antenna rotation, which does not require the calibrator to have a specific polarization scattering matrix (PSM). Compared with the currently existing calibration techniques, no prior knowledge of the calibrator PSM is required (in fact, any fixed-point target can be used as a calibrator); thus, the errors introduced by the mechanical process can be avoided. Simulations and data measured by radar verify the effectiveness of the method. This method has the potential to be extended to other fully polarimetric radar systems in the future, such as fully polarimetric weather radar, fully polarimetric synthetic aperture radar (SAR), and so on.
Journal Article
Search for New Complex Sequences for the Implementation of an Aviation Group Interaction System of Small-Sized Airborne Radars
Recently, when forming radar video frames for surface mapping, group-interacting compact onboard radar systems (CORS) are increasingly being utilized. In this context, for the cooperative functioning of the group, each compact radar should use its own unique marked signal as the probing signal. This signal must be distinguishable in the common channel and should not destructively affect the probing signals emitted by other radars within the group. This organization allows for associating the marked signals reflected from the underlying surface with specific CORS in the group. This requirement arises because each compact onboard radar in the group emits a single probing signal and then receives all reflected signals from the surface emitted by the other CORS in the group. Such an organization of the group-based system of technical vision requires the search for and study of specialized marked code structures used for phase modulation of probing signals to identify them in the shared radar channel. The study focuses on the search for new complex M-sequences with lower sidelobe levels of the normalized autocorrelation function compared to traditional M-sequences. This is achieved by replacing the traditional alphabet of positive and negative ones with an asymmetric set consisting of complex numbers. Using numerical methods and computer simulations, the optimal complex values of the sequence with the minimum sidelobe level in the autocorrelation function are determined. In addition to correlation properties, the phase-modulated signals generated based on the new marked sequences are also investigated. The results obtained open new possibilities for the construction of a group-based technical vision system, enabling cooperative surface probing among all CORS in the interacting group.
Journal Article
An Adaptive Parameter Evolutionary Marine Predators Algorithm for Joint Resource Scheduling of Cooperative Jamming Networked Radar Systems
This paper investigates the formation joint resource scheduling problem from the perspective of cooperative jamming against radar systems. First, the formation survivability is redefined based on the task requirements. Then, a hierarchical adaptive scheduling strategy solution framework is constructed for state prediction and detection fusion of the networked radar system. Considering the scene constraints, an Improved Adaptive Parameter Evolution Marine Predators Algorithm is designed as an optimizer and embedded in the proposed framework to jointly optimize the platform beam allocation and jamming mode selection. Based on the original algorithm, real number random coding is used to perform dimensional conversion of decision variables, an adaptive parameter evolution mechanism is designed to reduce the dependence on algorithm parameters, and an adaptive selection mechanism for dominant strategies and a search intensity control strategy are proposed to help decision-makers explore the optimal resource scheduling strategy quickly and accurately. Finally, considering the formation maneuvering behavior and incomplete information, the proposed method is compared with existing base strategies in different typical scenarios. It is proved that the proposed strategy can fully exploit the limited jamming resources and maximize the survivability of the formation in radar system cooperative jamming scenarios, demonstrating superior jamming performance and shorter decision time.
Journal Article