{"title":"Dynamic RCS Simulation Using Active Frequency Selective Surface","authors":"Dejun Feng, Yumeng Fang, Yameng Kong, Junjie Wang, Liwei Chen","doi":"10.1049/rsn2.70027","DOIUrl":"https://doi.org/10.1049/rsn2.70027","url":null,"abstract":"<p>In the experimental test of the radar system, it is extremely important to build a realistic experimental environment for electromagnetic target testing, which is often realised by the radar target simulation technology. Corner reflectors often simulate radar RCS features by the spatial arrangement; however, their electromagnetic characteristics are solidified and the RCS features differ from those of real targets. This paper proposes a target RCS simulation method based on AFSS echo power modulation. The core idea is to use AFSS reflection modulation to dynamically regulate the target power information to achieve flexible and fast control of the target radar RCS characteristics. Based on the AFSS echo power modulation model, the theoretical relationship between the modulation parameters and the RCS value is deduced, and the duty cycle of the scattering state control signal is used as an adjustable variable to realise the simulation of the dynamic RCS sequence of the mid-range target. The RCS simulation experiment is carried out based on the target measured data, and the simulation effect is analysed in terms of statistical characteristics and similarity coefficients. The simulation results show that the statistical characteristics of the simulated RCS sequence and the target RCS sequence are very close to each other with the mean value and standard deviation within 1 dBsm and the extreme value and extreme deviation within 3 dBsm. The method is of great significance in the field of radar system tests and electronic protection.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design of Spectrally Compatible Waveforms With Low Auto- and Cross-Correlation-Weighted Integrated Sidelobe Levels","authors":"Zhaobo Jia, Lei Yu, Yinsheng Wei","doi":"10.1049/rsn2.70024","DOIUrl":"https://doi.org/10.1049/rsn2.70024","url":null,"abstract":"<p>Low-correlation sidelobes are critical for spectrally compatible waveforms in multiple-input multiple-output (MIMO) radar systems. This study presents a novel algorithm for designing spectrally compatible waveforms for MIMO radar with low auto- and cross-correlation sidelobes to enhance weak target detection capability. We adopt the minimum auto- and cross-correlation-weighted integrated sidelobe level (ACWISL) as the objective function. Under spectral and constant modulus constraints, we formulate a nondeterministic polynomial time (NP)-hard problem. To solve this problem, we combine the block successive upper-bound minimisation (BSUM) and majorisation-minimisation (MM) algorithms to develop the BSUM-MM algorithm. The original problem is decomposed into several independent subproblems, which are iteratively solved using the MM algorithm. We also employ the fast Fourier transform (FFT) to significantly accelerate the calculation. Simulation results demonstrate that the proposed algorithm is superior in terms of computational efficiency and sidelobe performance.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gangyin Sun, Shiwen Chen, Li Zhang, Chaopeng Wu, Haikun Fang
{"title":"Long-Tailed Distributed Radar Emitter Signal Automatic Modulation Recognition Based on Decoupled Training","authors":"Gangyin Sun, Shiwen Chen, Li Zhang, Chaopeng Wu, Haikun Fang","doi":"10.1049/rsn2.70026","DOIUrl":"https://doi.org/10.1049/rsn2.70026","url":null,"abstract":"<p>The existing radar emitter modulation recognition methods typically assume that the data distribution across different types is balanced. But in reality, the number of signals of various kinds often follows a long-tail distribution, leading to model overfitting for the head classes and underfitting for the tail classes. As a result, the overall recognition performance of models under such data imbalances is suboptimal. A long-tail distribution automatic modulation recognition method based on decoupled training is proposed to address this issue. Based on the ResNeXt network, the proposed method decouples the model training process into two stages: a feature extraction phase under the imbalanced dataset and the classifier learning stage under a balanced dataset. The classifier boundary is fine-tuned by <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>τ</mi>\u0000 </mrow>\u0000 <annotation> $tau $</annotation>\u0000 </semantics></math>-normalization method. Compared to existing radar emitter modulation recognition frameworks, the proposed method achieves an overall recognition accuracy of 86.8% when the data imbalance factor is 0.01, surpassing the baseline model by 5%, and improves the performance of radar emitters modulation recognition in the real environment.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brian W.-H. Ng, Elias Aboutanios, Luke Rosenberg, Marco Martorella
{"title":"Guest Editorial: Selected Papers From Radar 2023 (Sydney, Australia)","authors":"Brian W.-H. Ng, Elias Aboutanios, Luke Rosenberg, Marco Martorella","doi":"10.1049/rsn2.70023","DOIUrl":"https://doi.org/10.1049/rsn2.70023","url":null,"abstract":"<p>It is our great pleasure to introduce a series of extended papers from the 2023 IEEE International Radar Conference (RADAR 2023), 6–10 November 2023, held in Sydney, Australia. The conference theme was Dreaming the Radar Future. Befitting this theme, the conference received a diverse range of contributions from leading international researchers. A total of 200 full papers were published in the proceedings of RADAR 2023. A selection of authors from the best papers, including the winners and finalists of the best paper and best student paper competitions, were invited to submit extended journal papers for this special issue. The extended papers were required to contain at least 40% new material compared with the conference submissions and were subjected to a separate peer-review process, conducted with the same rigour as regular issues of <i>IET Radar</i>, <i>Sonar & Navigation</i>.</p><p>This special issue contains 8 papers, across a wide range of application areas. These include space domain awareness, distributed radar sensor networks, flying target detection from SAR images, clutter processing, drone characterisation, track confirmation, polarimetry for target imaging and over the horizon radar.</p><p>Achieving synchronisation presents a major challenge for the deployment of distributed network of radars. Addressing this problem can unleash the vast potential of the sensor network. Kenney et al. [<span>1</span>] present a decentralised technique for attaining frequency, time and phase synchronisation across a distributed network. The presented approach builds on a previously published method for correcting phase and clock bias, and has the advantage of not requiring RF hardware upgrades. A comprehensive theoretical analysis is presented in this paper, along with simulations, that show the proposed technique approaches the theoretical performance limit. A beamforming scenario is used to illustrate how the proposed technique can be implemented to solve a practical problem.</p><p>Tracking evasive targets present a great challenge to modern radar systems, particularly for radar resource management. This problem is highly complex, with multiple agents affecting many scenarios. Dolinger et al. [<span>2</span>] present an approach to this problem with reinforcement learning set within a game theoretic context. Three game theory strategies are implemented and tested in a simulated radar environment, with the performance compared against heuristic methods. The results show that collaborative methods achieve greater performance, and that finer nuances in the performance that point towards future research directions.</p><p>Howard and Nguyen [<span>3</span>] present a collection of techniques for manipulating the radar ambiguity function for over the horizon radar. They present a novel characterisation of the ambiguity function in terms of twisted convolutions and show how it can be transformed by an area preserving linear transformation of the dela","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fusion of HRRP Time-Frequency Analysis and Multi-Scale Features for Convolutional Neural Network-Based Target Recognition","authors":"Xiaohui Wei, Zhulin Zong","doi":"10.1049/rsn2.70019","DOIUrl":"https://doi.org/10.1049/rsn2.70019","url":null,"abstract":"<p>For radar target recognition in high-resolution range profiles (HRRP) under low signal-to-noise ratio (SNR) conditions, traditional methods typically involve denoising followed by recognition. However, these methods struggle with complex noise. To enhance HRRP information extraction, this paper proposes an integrated approach combining noise reduction and recognition. First, the short-time Fourier transform (STFT) is improved with a complex Gaussian window to enhance time-frequency resolution. Then, multi-scale analysis is applied by introducing scale values to better capture detailed target features. Differential operations are used to highlight scattering points and edges, improving recognition accuracy. A convolutional neural network (CNN) is employed to extract multi-level features for target recognition. Experimental results on a simulated HRRP dataset from the U.S. Air Force Research Laboratory (AFRL) demonstrate the proposed method's superior performance. It outperforms traditional methods in both accuracy and robustness, offering stronger noise resistance and better utilisation of HRRP's rich features, providing an effective solution for radar target recognition tasks.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143861544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Longhao Xie, Wenxing Ren, Ziyang Cheng, Ming Li, Huiyong Li
{"title":"Power and Waveform Resource Allocation Method of LPI Netted Radar for Target Search and Tracking","authors":"Longhao Xie, Wenxing Ren, Ziyang Cheng, Ming Li, Huiyong Li","doi":"10.1049/rsn2.70022","DOIUrl":"https://doi.org/10.1049/rsn2.70022","url":null,"abstract":"<p>A joint power and waveform resource allocation algorithm is proposed for netted radar integrated search and tracking tasks with low probability of intercept. For the search and tracking performance, the detection probability and the posterior Cramér-Rao lower bound of the target are adopted separately. The optimization problem of joint resource allocation is solved by controlling the radar node selection, power allocation, waveform selection, and pulse duration, to minimise the total power of the netted radar while meeting the search and tracking performance for a given target. The intelligent optimization methods are used to solve the problem, and the effectiveness of the proposed method is verified by simulation.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paulo Silva, Marcelo G. S. Bruno, Victor di Santis, Alison Moraes, Jonas Sousasantos, Leonardo Marini-Pereira
{"title":"An Alternative Approach for Pseudorange Variance Estimation Under Scintillation Environments Using Markov-Rao-Blackwellized Particle Filtering","authors":"Paulo Silva, Marcelo G. S. Bruno, Victor di Santis, Alison Moraes, Jonas Sousasantos, Leonardo Marini-Pereira","doi":"10.1049/rsn2.70017","DOIUrl":"https://doi.org/10.1049/rsn2.70017","url":null,"abstract":"<p>Ionospheric scintillations, arising from variations in phase/amplitude of radio signals traversing the ionosphere, pose significant challenges to Global Navigation Satellite System (GNSS) positioning, particularly in low-latitude regions. This paper proposes a Rao-Blackwellized Particle Filter (RBPF) integrated with a Markov chain model to comprehensively characterise and mitigate the impact of ionospheric scintillation on GNSS positioning. Unlike traditional methods, the Markov-RBPF framework offers enhanced versatility in assessing scintillation dynamics both spatially and temporally, allowing for precise modelling of scintillation evolution over varying nighttime hours and months of the year. Through simulations, the authors demonstrate the superior performance of the proposed Markov-RBPF compared to conventional Extended Kalman Filters (EKF), with position root-mean-square errors below 2 m in a scenario of strong scintillation events in October 2014. This showcases its robustness and versatility in improving GNSS positioning accuracy amidst challenging ionospheric conditions.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143831316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Polarimetry for Sparse Multistatic 3D SAR","authors":"Richard Welsh, Daniel Andre, Mark Finnis","doi":"10.1049/rsn2.70020","DOIUrl":"https://doi.org/10.1049/rsn2.70020","url":null,"abstract":"<p>There is significant interest in multistatic SAR image formation, due to the increased development of satellite constellations and UAV swarms for remote sensing applications. The exploitation of the finer resolution and wider coverage of these geometries has been shown to reduce the often-impractical data collection requirements of 3D SAR imagery; this offers advantages such as improved target identification and the removal of layover artefacts. This paper presents a novel polarimetric generalisation of the SSARVI algorithm, which was previously developed to exploit sparse aperture multistatic collections for 3D SAR image formation. The new algorithm presented here, named the PolSSARVI algorithm, combines polarimetrically weighted interferograms for determining the 3D scatterer locations from sparse aperture polarimetric collections. The bistatic generalised Huynen fork polarimetric parameters are then determined for the multistatic PolSSARVI 3D SAR renderings. This new approach was tested on both simulated and experimental data. Experimental imagery was formed using measurements from the Cranfield GBSAR laboratory.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143818409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"E-SDHGN: A Multifunction Radar Working Mode Recognition Framework in Complex Electromagnetic Environments","authors":"Minhong Sun, Hangxin Chen, Zhangyi Shao, Zhaoyang Qiu, Zhenyin Wen, Deguo Zeng","doi":"10.1049/rsn2.70025","DOIUrl":"https://doi.org/10.1049/rsn2.70025","url":null,"abstract":"<p>A multifunction radar (MFR) can operate in multiple modes and perform various tasks such as surveillance, detection, fire control, search and tracking. Recognising an MFR's operating mode is critical in electronic warfare and intelligence reconnaissance, aiding practical threat assessment and countermeasure tasks. However, current recognition methods face challenges such as overlapping parameters among working modes and suboptimal recognition accuracy under conditions with parameter errors, missing pulses and false pulses. Spurred by these concerns, this paper proposes an entropy-enhanced spatial-deformable hybrid multiscale group network (E-SDHGN) to recognise the operating mode of an MFR and address these challenges. E-SDHGN employs multidimensional entropy computations to construct robust features and integrates deformable convolution and positional encoding to enhance the model's ability to capture complex features. Additionally, it enhances feature extraction and fusion within the dynamic shared residual network (DSRN) module by integrating KAN modules and hybrid weight-sharing strategies. Additionally, an adaptive margin feature module based on attention mechanisms improves classification accuracy in overlapping parameter conditions. Experimental results demonstrate that E-SDHGN achieves superior recognition accuracy and robustness, even under challenging parameter errors, missing pulses and false pulses. This underscores its value for applications in complex electromagnetic environments.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Apostolos Pappas, Jacco J. M. de Wit, Francesco Fioranelli, Bas Jacobs
{"title":"Multitask Learning Approaches Towards Drone Characterisation With Radar","authors":"Apostolos Pappas, Jacco J. M. de Wit, Francesco Fioranelli, Bas Jacobs","doi":"10.1049/rsn2.70012","DOIUrl":"https://doi.org/10.1049/rsn2.70012","url":null,"abstract":"<p>For the effective deployment of countermeasures against drones, information on their intent is crucial. There are several indicators for a drone's intent, for example, its size, payload and behaviour. In this paper, a method is proposed to estimate two or more of the following four indicators: a drone's wing type, its number of rotors, the presence of a payload and its mean rotor rotation rate. Specifically, three multitask learning (MTL) approaches are analysed for the simultaneous estimation of several of these indicators based on radar micro-Doppler spectrograms. MTL refers to training neural networks simultaneously for multiple related tasks. The assumption is that if tasks share features between them, an MTL model is easier to train and has improved generalisation capabilities as compared to separately trained single-task neural networks. The proposed MTL approaches are validated with experimental data and in a variety of combined classification and regression tasks. The results show that MTL approaches can provide improvement in several tasks compared with conventional approaches.</p>","PeriodicalId":50377,"journal":{"name":"Iet Radar Sonar and Navigation","volume":"19 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/rsn2.70012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}