Pub Date : 2024-10-01DOI: 10.1109/TRS.2024.3471696
Hiroki Mori;Ryota Sekiya
Some existing radar imaging apparatuses require a large number of transmitting and receiving antennas and, thus, impose stringent requirements on hardware design. In this article, we propose a millimeter-wave radar imaging method that combines multistatic radar with coprime measurements, to significantly reduce the number of antennas and the amount of data. The proposed radar array system replaces every monostatic radar with a pair comprising a separated transmitter and receiver along with phase corrections. Since multiple receivers can simultaneously receive the reflection when a transmitter emits a signal and then efficiently create virtual subarrays obtained by coprime measurements, the proposed radar array system can further reduce the number of measurements (antennas) and the amount of data compared with the existing schemes. Our proposal is demonstrated through simulations and experiments, and the results indicate that the proposed radar array system is advantageous in implementation in terms of hardware design and data acquisition time.
{"title":"Millimeter-Wave Radar Imaging Using Multistatic Coprime Array Configuration for Invisible Object Testing","authors":"Hiroki Mori;Ryota Sekiya","doi":"10.1109/TRS.2024.3471696","DOIUrl":"https://doi.org/10.1109/TRS.2024.3471696","url":null,"abstract":"Some existing radar imaging apparatuses require a large number of transmitting and receiving antennas and, thus, impose stringent requirements on hardware design. In this article, we propose a millimeter-wave radar imaging method that combines multistatic radar with coprime measurements, to significantly reduce the number of antennas and the amount of data. The proposed radar array system replaces every monostatic radar with a pair comprising a separated transmitter and receiver along with phase corrections. Since multiple receivers can simultaneously receive the reflection when a transmitter emits a signal and then efficiently create virtual subarrays obtained by coprime measurements, the proposed radar array system can further reduce the number of measurements (antennas) and the amount of data compared with the existing schemes. Our proposal is demonstrated through simulations and experiments, and the results indicate that the proposed radar array system is advantageous in implementation in terms of hardware design and data acquisition time.","PeriodicalId":100645,"journal":{"name":"IEEE Transactions on Radar Systems","volume":"2 ","pages":"1036-1047"},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142524139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Time-delay estimation (TDE) using ground penetrating radar (GPR) is of great importance in roadway surveys. The conventional GPR methods apply a uniform sampling strategy for TDE, which requires numerous frequency sampling points, leading to lengthy data acquisition time and large data storage, especially for ultra-wideband (UWB) radar. Moreover, detecting the overlapped backscattered echoes from the thin layer of roadways remains a challenge in TDE, due to the limited resolution of GPR and the characteristics of GPR signals. To address these issues, we derive a co-prime sampling strategy-based TDE for thin layers in roadway survey by exploiting off-grid sparse Bayesian learning (OGSBL), referred to co-prime-OGSBL. In our scheme, the sampling rate of GPR signals with a co-prime sampling strategy is greatly reduced compared with the uniform sampling, which therefore reduces the data acquisition burden and computational complexity. The estimation performance of time delays and thickness is also enhanced with OGSBL by utilizing radar pulse, co-prime sampling, and noncircularity of GPR signals. Both simulation and experimental results demonstrate the efficiency and accuracy of the proposed method in the estimation of time delays and thickness.
{"title":"Co-Prime Sampling-Based Time-Delay Estimation for Roadway Survey by Ground Penetrating Radar via Off-Grid Sparse Bayesian Learning","authors":"Jingjing Pan;Huimin Pan;Meng Sun;Yide Wang;Vincent Baltazart;Xudong Dong;Jun Zhao;Xiaofei Zhang;Hing Cheung So","doi":"10.1109/TRS.2024.3467993","DOIUrl":"https://doi.org/10.1109/TRS.2024.3467993","url":null,"abstract":"Time-delay estimation (TDE) using ground penetrating radar (GPR) is of great importance in roadway surveys. The conventional GPR methods apply a uniform sampling strategy for TDE, which requires numerous frequency sampling points, leading to lengthy data acquisition time and large data storage, especially for ultra-wideband (UWB) radar. Moreover, detecting the overlapped backscattered echoes from the thin layer of roadways remains a challenge in TDE, due to the limited resolution of GPR and the characteristics of GPR signals. To address these issues, we derive a co-prime sampling strategy-based TDE for thin layers in roadway survey by exploiting off-grid sparse Bayesian learning (OGSBL), referred to co-prime-OGSBL. In our scheme, the sampling rate of GPR signals with a co-prime sampling strategy is greatly reduced compared with the uniform sampling, which therefore reduces the data acquisition burden and computational complexity. The estimation performance of time delays and thickness is also enhanced with OGSBL by utilizing radar pulse, co-prime sampling, and noncircularity of GPR signals. Both simulation and experimental results demonstrate the efficiency and accuracy of the proposed method in the estimation of time delays and thickness.","PeriodicalId":100645,"journal":{"name":"IEEE Transactions on Radar Systems","volume":"2 ","pages":"966-978"},"PeriodicalIF":0.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article presents a novel constant false alarm rate (CFAR) compressed detection approach for human detection using the impulse radio ultrawideband (IR-UWB) radar. The associated Xampling scheme operates way below the Nyquist limit and is designed to minimize the sensing matrix coherence (SMC), without increasing the implementation complexity. The proposed signal-processing architecture aims to detect both moving and stationary people in the framework of heavy-cluttered use cases, such as smart factory indoor environments. To address this challenge, we not only rely on standard radar signal processing, including moving target indicator (MTI) filtering, noise whitening, and Doppler focusing (DF), but also introduce two new algorithms for joint sparse reconstruction (SR) and CFAR detection, in fast-time and range-Doppler domains, respectively. We propose a specific detection statistic, which is proven to be appropriate for both algorithms, its distribution being identified and then validated by standard goodness-of-fit tests. Moreover, it enables reducing the CFAR scheme complexity, since the associated detection threshold is invariant to the noise power, thus making unnecessary its estimation. The proposed approach is finally validated using both simulated and experimentally measured data in an Industry 4.0 indoor environment, for several canonical scenarios. The effectiveness of our CFAR compressed detection algorithms for human detection is thus fully demonstrated, and their performance is assessed and compared to that obtained by signal processing at the Nyquist sampling rate.
{"title":"CFAR Compressed Detection in Heavy-Cluttered Indoor Environments Using IR-UWB Radar: New Experimentally Supported Results","authors":"Zaynab Baydoun;Roua Youssef;Emanuel Radoi;Stéphane Azou;Tina Yaacoub","doi":"10.1109/TRS.2024.3467549","DOIUrl":"https://doi.org/10.1109/TRS.2024.3467549","url":null,"abstract":"This article presents a novel constant false alarm rate (CFAR) compressed detection approach for human detection using the impulse radio ultrawideband (IR-UWB) radar. The associated Xampling scheme operates way below the Nyquist limit and is designed to minimize the sensing matrix coherence (SMC), without increasing the implementation complexity. The proposed signal-processing architecture aims to detect both moving and stationary people in the framework of heavy-cluttered use cases, such as smart factory indoor environments. To address this challenge, we not only rely on standard radar signal processing, including moving target indicator (MTI) filtering, noise whitening, and Doppler focusing (DF), but also introduce two new algorithms for joint sparse reconstruction (SR) and CFAR detection, in fast-time and range-Doppler domains, respectively. We propose a specific detection statistic, which is proven to be appropriate for both algorithms, its distribution being identified and then validated by standard goodness-of-fit tests. Moreover, it enables reducing the CFAR scheme complexity, since the associated detection threshold is invariant to the noise power, thus making unnecessary its estimation. The proposed approach is finally validated using both simulated and experimentally measured data in an Industry 4.0 indoor environment, for several canonical scenarios. The effectiveness of our CFAR compressed detection algorithms for human detection is thus fully demonstrated, and their performance is assessed and compared to that obtained by signal processing at the Nyquist sampling rate.","PeriodicalId":100645,"journal":{"name":"IEEE Transactions on Radar Systems","volume":"2 ","pages":"991-1006"},"PeriodicalIF":0.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-23DOI: 10.1109/TRS.2024.3466134
Yuan-Peng Zhang;Zhi-Hao Wang;Tai-Yang Liu;Yan Xie;Ying Luo
Heterogeneous radar network systems can provide multiband and multiangle information about targets, enhancing the ability to recognize space targets. This article proposes a space target recognition method based on a bidirectional gated recurrent unit (BiGRU)-Transformer and dual graph fusion (BiGT-DGF) network. Through a temporal information extraction subnetwork, the BiGRU and Transformer are used to dynamically model a radar cross section (RCS) time series under multiple bands and angles, effectively exploiting both the local and global temporal dependencies. Through a spatial information extraction subnetwork, which integrates predefined graphs with self-adaptive graphs, the spatial dependencies between various radars are dynamically and adaptively captured. On this basis, the prediction output layer utilizes the spatiotemporal information extracted by the above two subnetworks to effectively recognize space targets. The experimental results show that the proposed method can reliably recognize space targets even under low signal-to-noise ratios (SNRs) and low pulse repetition frequencies.
{"title":"Space Target Recognition Based on Radar Network Systems With BiGRU-Transformer and Dual Graph Fusion Network","authors":"Yuan-Peng Zhang;Zhi-Hao Wang;Tai-Yang Liu;Yan Xie;Ying Luo","doi":"10.1109/TRS.2024.3466134","DOIUrl":"https://doi.org/10.1109/TRS.2024.3466134","url":null,"abstract":"Heterogeneous radar network systems can provide multiband and multiangle information about targets, enhancing the ability to recognize space targets. This article proposes a space target recognition method based on a bidirectional gated recurrent unit (BiGRU)-Transformer and dual graph fusion (BiGT-DGF) network. Through a temporal information extraction subnetwork, the BiGRU and Transformer are used to dynamically model a radar cross section (RCS) time series under multiple bands and angles, effectively exploiting both the local and global temporal dependencies. Through a spatial information extraction subnetwork, which integrates predefined graphs with self-adaptive graphs, the spatial dependencies between various radars are dynamically and adaptively captured. On this basis, the prediction output layer utilizes the spatiotemporal information extracted by the above two subnetworks to effectively recognize space targets. The experimental results show that the proposed method can reliably recognize space targets even under low signal-to-noise ratios (SNRs) and low pulse repetition frequencies.","PeriodicalId":100645,"journal":{"name":"IEEE Transactions on Radar Systems","volume":"2 ","pages":"950-965"},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Interrupted sampling repeater jamming (ISRJ) is an effective way to suppress normal radar probing in modern electronic warfare, and ISRJ suppression is essential in the radar signal processing stage. Accurately locating the position of the jamming signal is the first step to suppress the jamming signal. However, the traditional constant false alarm rate (CFAR) has performance loss with the characteristics of intensive distribution, extensive dynamic power range, and nonperiodical transmitting. This article proposes an ISRJ detection method based on a fusion Transformer and CFAR. First, the feature extraction model based on the Transformer is built to extract the continuous distribution features of ISRJ, forming rough detection results. Then, a CFAR detector is derived based on the rough detection result to estimate detector parameters. Third, the jamming features obtained by the Transformer, CFAR detector, and other features (such as instantaneous power and average power) are fused by a decision tree to realize robust detection in a low jamming-to-signal noise ratio (JSNR). Finally, we conducted simulated experiments to verify the effectiveness of the proposed method.
{"title":"Intensive Interrupted Sampling Repeater Jamming Detection Based on Transformer-CFAR Fusion Detection Model","authors":"Haonan Zhang;Shaopeng Wei;Song Wei;Lei Zhang;Peng Ren;Yejian Zhou","doi":"10.1109/TRS.2024.3465017","DOIUrl":"https://doi.org/10.1109/TRS.2024.3465017","url":null,"abstract":"Interrupted sampling repeater jamming (ISRJ) is an effective way to suppress normal radar probing in modern electronic warfare, and ISRJ suppression is essential in the radar signal processing stage. Accurately locating the position of the jamming signal is the first step to suppress the jamming signal. However, the traditional constant false alarm rate (CFAR) has performance loss with the characteristics of intensive distribution, extensive dynamic power range, and nonperiodical transmitting. This article proposes an ISRJ detection method based on a fusion Transformer and CFAR. First, the feature extraction model based on the Transformer is built to extract the continuous distribution features of ISRJ, forming rough detection results. Then, a CFAR detector is derived based on the rough detection result to estimate detector parameters. Third, the jamming features obtained by the Transformer, CFAR detector, and other features (such as instantaneous power and average power) are fused by a decision tree to realize robust detection in a low jamming-to-signal noise ratio (JSNR). Finally, we conducted simulated experiments to verify the effectiveness of the proposed method.","PeriodicalId":100645,"journal":{"name":"IEEE Transactions on Radar Systems","volume":"2 ","pages":"936-949"},"PeriodicalIF":0.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1109/TRS.2024.3462471
Stephen Searle;Gottfried Lechner;Kutluyil Doğançay
Passive bistatic radar (PBR) employs an ambient source of radio frequency (RF) energy, such as a television transmitter, as an illuminator. The continuous nature of such transmissions results in significant interference in the surveillance signal, as direct-path (DP) transmission and returns from clutter. These must be suppressed in order to make target returns detectable. Delay-Doppler processing can be enhanced by demodulating and reconstructing the captured reference signal. However, target detectability is known to be affected when a reconstructed signal is used in the zero-Doppler cancellation (ZDC) process. This study proposes transmitter nonlinearity as a reason for poor cancellation. Analysis of ambiguity peak-to-floor measures suggests that under certain conditions unmodeled nonlinearity will cause degradation in ZDC. Several methods of nonlinearity estimation and modeling are proposed. Simulation evaluates these methods with various levels of nonlinearity and sensor noise. The methods are applied to ambiguity processing of terrestrial digital video broadcast (DVB-T) real data in both single-channel and two-channel receiver configurations. The results are explained with reference to the earlier analysis.
{"title":"Clutter Cancellation in Passive Bistatic Radar With Transmitter Nonlinearity","authors":"Stephen Searle;Gottfried Lechner;Kutluyil Doğançay","doi":"10.1109/TRS.2024.3462471","DOIUrl":"https://doi.org/10.1109/TRS.2024.3462471","url":null,"abstract":"Passive bistatic radar (PBR) employs an ambient source of radio frequency (RF) energy, such as a television transmitter, as an illuminator. The continuous nature of such transmissions results in significant interference in the surveillance signal, as direct-path (DP) transmission and returns from clutter. These must be suppressed in order to make target returns detectable. Delay-Doppler processing can be enhanced by demodulating and reconstructing the captured reference signal. However, target detectability is known to be affected when a reconstructed signal is used in the zero-Doppler cancellation (ZDC) process. This study proposes transmitter nonlinearity as a reason for poor cancellation. Analysis of ambiguity peak-to-floor measures suggests that under certain conditions unmodeled nonlinearity will cause degradation in ZDC. Several methods of nonlinearity estimation and modeling are proposed. Simulation evaluates these methods with various levels of nonlinearity and sensor noise. The methods are applied to ambiguity processing of terrestrial digital video broadcast (DVB-T) real data in both single-channel and two-channel receiver configurations. The results are explained with reference to the earlier analysis.","PeriodicalId":100645,"journal":{"name":"IEEE Transactions on Radar Systems","volume":"2 ","pages":"979-990"},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this article, we investigate the joint estimation of range and velocity of targets using a wideband frequency-modulated continuous wave (FMCW) radar in the presence of range-Doppler coupling. To mitigate the effects of range-Doppler coupling, we propose a phase compensation framework based on a decoupled matrix atomic norm minimization (DANM). Subsequently, we propose a concave log-det heuristic to bridge the gap between atomic $ell _{0}$