Pub Date : 2025-11-11DOI: 10.1109/TIM.2025.3627380
Andrzej Dukata;Waldemar Susek;Mirosław Czyżewski
The traditional Nicolson–Ross–Weir (NRW) method of extracting permittivity and permeability was used in the above work. Some of the tested materials were anisotropic and nonmagnetic, while others exhibited both electric and magnetic anisotropies. As is known, the NRW method developed for isotropic materials fails in the latter case. Appropriate formulas for determining permittivity and permeability tensors of anisotropic materials, which should be used in the commented article, are presented and briefly explained.
{"title":"Comments on “Measurement of Anisotropic Material by Using Orthomode Transducer for High Efficiency”","authors":"Andrzej Dukata;Waldemar Susek;Mirosław Czyżewski","doi":"10.1109/TIM.2025.3627380","DOIUrl":"https://doi.org/10.1109/TIM.2025.3627380","url":null,"abstract":"The traditional Nicolson–Ross–Weir (NRW) method of extracting permittivity and permeability was used in the above work. Some of the tested materials were anisotropic and nonmagnetic, while others exhibited both electric and magnetic anisotropies. As is known, the NRW method developed for isotropic materials fails in the latter case. Appropriate formulas for determining permittivity and permeability tensors of anisotropic materials, which should be used in the commented article, are presented and briefly explained.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-3"},"PeriodicalIF":5.9,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145510075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quantifying Young’s modulus and Poisson’s ratio of underfill (UF) is critical in clarifying material failure mechanisms for better optimizing their performance in reducing thermal stresses on solder joints in flip-chip devices. Conventional mechanical methods are generally developed for the pure UF block and cannot directly measure thin UF layers sandwiched in heterogeneous multilayered flip-chip devices during service. Nondestructive ultrasonic methods are more promising but are challenged by complex wave propagation induced by multilayered, anisotropic acoustic properties. This work presents a noncontact laser ultrasonic (LU) method for in situ and simultaneous measurement of elastic constants and thickness of a thin UF layer in a silicon–UF–silicon sandwich structure. Longitudinal and transverse waves in divergent propagation directions are acquired by using a line-scan point laser transmitter and a fixed-point receiver on opposite surfaces. Young’s modulus, Poisson’s ratio, and thickness of the sandwiched UF layer are inversely determined by iteratively matching experimental LU travel times with theoretical predictions considering interface reflection, refraction, and mode conversion effects, with relative errors to ultrasonic measured reference values <3.722%. The in situ LU method is advantageous in continuously monitoring mechanical property evolution during various cyclic tests, advancing reliability assessment and fabrication optimization of UF materials in real-life electronic packaging applications.
{"title":"In Situ Measurement of Elastic Constants and Thickness of Silicon–Underfill–Silicon Sandwiched Electronic Package Using Noncontact Laser Ultrasound Array","authors":"Huanqing Cao;Zhijun Yao;Qimin Zhu;Ruoyu Zhang;Gaolong Lv;Pengli Zhu;Jian Yang;Xinyu Wu;Shifeng Guo","doi":"10.1109/TIM.2025.3627352","DOIUrl":"https://doi.org/10.1109/TIM.2025.3627352","url":null,"abstract":"Quantifying Young’s modulus and Poisson’s ratio of underfill (UF) is critical in clarifying material failure mechanisms for better optimizing their performance in reducing thermal stresses on solder joints in flip-chip devices. Conventional mechanical methods are generally developed for the pure UF block and cannot directly measure thin UF layers sandwiched in heterogeneous multilayered flip-chip devices during service. Nondestructive ultrasonic methods are more promising but are challenged by complex wave propagation induced by multilayered, anisotropic acoustic properties. This work presents a noncontact laser ultrasonic (LU) method for in situ and simultaneous measurement of elastic constants and thickness of a thin UF layer in a silicon–UF–silicon sandwich structure. Longitudinal and transverse waves in divergent propagation directions are acquired by using a line-scan point laser transmitter and a fixed-point receiver on opposite surfaces. Young’s modulus, Poisson’s ratio, and thickness of the sandwiched UF layer are inversely determined by iteratively matching experimental LU travel times with theoretical predictions considering interface reflection, refraction, and mode conversion effects, with relative errors to ultrasonic measured reference values <3.722%. The in situ LU method is advantageous in continuously monitoring mechanical property evolution during various cyclic tests, advancing reliability assessment and fabrication optimization of UF materials in real-life electronic packaging applications.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-12"},"PeriodicalIF":5.9,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-24DOI: 10.1109/TIM.2025.3625329
František Martínek;Vilém Neděla;Vladimír Tichý;Adam Antálek
A new tool for the simulation of electron-gas-sample interaction phenomena under real experimental conditions of elevated gas pressure in electron microscopes is introduced. It allows in-silico testing and optimization of detection systems of any given geometry, taking spatially variable electric field and gas flow into account. Its possibilities are demonstrated through a detailed analysis of a widely used environmental secondary detector variant (ESD-V) geometry, leading to a proposal and experimental proof of a significant increase in its secondary electron (SE) collection efficiency. In addition, suppression of the detected BSE signal, i.e., material contrast and edge effect, is demonstrated on the image of an embolized human benign tumor. The validity of the model is verified by comparison with experimental data of overall signal development in varying pressure.
{"title":"A New Tool for Numerical Analysis of Signal Creation Processes in ESEM/A-ESEM","authors":"František Martínek;Vilém Neděla;Vladimír Tichý;Adam Antálek","doi":"10.1109/TIM.2025.3625329","DOIUrl":"https://doi.org/10.1109/TIM.2025.3625329","url":null,"abstract":"A new tool for the simulation of electron-gas-sample interaction phenomena under real experimental conditions of elevated gas pressure in electron microscopes is introduced. It allows in-silico testing and optimization of detection systems of any given geometry, taking spatially variable electric field and gas flow into account. Its possibilities are demonstrated through a detailed analysis of a widely used environmental secondary detector variant (ESD-V) geometry, leading to a proposal and experimental proof of a significant increase in its secondary electron (SE) collection efficiency. In addition, suppression of the detected BSE signal, i.e., material contrast and edge effect, is demonstrated on the image of an embolized human benign tumor. The validity of the model is verified by comparison with experimental data of overall signal development in varying pressure.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-10"},"PeriodicalIF":5.9,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145455788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-09DOI: 10.1109/TIM.2025.3619275
Dongjian Wang;Xiufen Ye;Hong Liu;Hanjie Huang;Xianye Ben
In seabed topography reconstruction, side-scan sonar (SSS) provides wide-area seafloor imaging as the detection equipment moves, but it cannot capture the region directly beneath the equipment, leaving gaps in coverage. On the other hand, forward-looking sonar (FLS), typically mounted at the front of the equipment, offers real-time imaging of the seafloor ahead, though its detection range is limited and it cannot cover the entire area. Therefore, combining FLS with SSS, along with navigation data, enables comprehensive seafloor mapping by filling the gaps in SSS coverage and improving the accuracy of seabed topography reconstruction. Existing methods insert FLS images into the SSS coverage gaps by combining navigation data, but FLS images suffer from low resolution, blurred target details, and visible seams between the filled regions and the surrounding SSS images, leading to a lack of overall image coherence. This article proposes a multisensor data fusion method that integrates data from SSS, FLS, altimeter, GPS, and inertial navigation systems (INSs). The method employs FLS image enhancement, intensity matching, and a weight-adjusted fusion strategy to improve the clarity of FLS images and significantly enhance the overall quality of the fused imagery. Experimental results show that our method greatly improves the visual coherence of the fused FLS and SSS images, achieves smooth edge transitions, eliminates visible seams, and enhances the precision of seabed topography reconstruction.
{"title":"A Multisensor Data Fusion Method for Seabed Topography Reconstruction Based on Image Enhancement and Intensity Matching","authors":"Dongjian Wang;Xiufen Ye;Hong Liu;Hanjie Huang;Xianye Ben","doi":"10.1109/TIM.2025.3619275","DOIUrl":"https://doi.org/10.1109/TIM.2025.3619275","url":null,"abstract":"In seabed topography reconstruction, side-scan sonar (SSS) provides wide-area seafloor imaging as the detection equipment moves, but it cannot capture the region directly beneath the equipment, leaving gaps in coverage. On the other hand, forward-looking sonar (FLS), typically mounted at the front of the equipment, offers real-time imaging of the seafloor ahead, though its detection range is limited and it cannot cover the entire area. Therefore, combining FLS with SSS, along with navigation data, enables comprehensive seafloor mapping by filling the gaps in SSS coverage and improving the accuracy of seabed topography reconstruction. Existing methods insert FLS images into the SSS coverage gaps by combining navigation data, but FLS images suffer from low resolution, blurred target details, and visible seams between the filled regions and the surrounding SSS images, leading to a lack of overall image coherence. This article proposes a multisensor data fusion method that integrates data from SSS, FLS, altimeter, GPS, and inertial navigation systems (INSs). The method employs FLS image enhancement, intensity matching, and a weight-adjusted fusion strategy to improve the clarity of FLS images and significantly enhance the overall quality of the fused imagery. Experimental results show that our method greatly improves the visual coherence of the fused FLS and SSS images, achieves smooth edge transitions, eliminates visible seams, and enhances the precision of seabed topography reconstruction.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-11"},"PeriodicalIF":5.9,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145351899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-08DOI: 10.1109/TIM.2025.3619247
Shuai Cao;Shengwei Chen;Yaping Liu;Ruizhi Chen
Traditional time difference of arrival (TDoA)-based localization methods cannot autonomously detect or discard large anomalies, leading to significant errors with unbalanced measurements. This study introduces a TDoA-based clustering combined weighted (CCW) method that leverages measurement consistency to identify anomalies in redundant measurements, using only those with normal errors to enhance localization accuracy in unbalanced scenarios. In 2-D localization, at least three base stations are needed to determine the position. With three stations, the CCW method simplifies the solution by transforming the coordinate system and resolving the co-linear problem. When more than three stations are present, the method generates multiple three-base station combinations (TBSCs), solving each to obtain minimal measurement solutions. These solutions are clustered to find subsets that meet the clustering criteria. If all minimal measurement solutions diverge or fail to converge, the CCW method performs a systematic, exhaustive search to identify and exclude unreliable base stations until a valid aggregated class is found or only three stations remain. The final position estimate is the weighted average of the elements in this class, with weights based on the TBSC’s Cramér–Rao lower bound (CRLB). Simulation results show that under unbalanced noise conditions, especially with six and eight base stations, a threshold effect occurs. When the ratio of the abnormal error level to the normal error level exceeds a certain level, the CCW method outperforms other techniques by detecting and removing abnormal measurements, thus improving localization accuracy by focusing on primarily accurate measurements. In real acoustic indoor localization experiments, the CCW method significantly outperformed other methods. In static tests, it achieved sub-0.36 m accuracy for 90% of estimated positions, and in dynamic tests, it closely matched real trajectories with an average anomaly rate of only 1.1%.
{"title":"Clustering Combined Weighted TDoA Localization for Outlier Suppression","authors":"Shuai Cao;Shengwei Chen;Yaping Liu;Ruizhi Chen","doi":"10.1109/TIM.2025.3619247","DOIUrl":"https://doi.org/10.1109/TIM.2025.3619247","url":null,"abstract":"Traditional time difference of arrival (TDoA)-based localization methods cannot autonomously detect or discard large anomalies, leading to significant errors with unbalanced measurements. This study introduces a TDoA-based clustering combined weighted (CCW) method that leverages measurement consistency to identify anomalies in redundant measurements, using only those with normal errors to enhance localization accuracy in unbalanced scenarios. In 2-D localization, at least three base stations are needed to determine the position. With three stations, the CCW method simplifies the solution by transforming the coordinate system and resolving the co-linear problem. When more than three stations are present, the method generates multiple three-base station combinations (TBSCs), solving each to obtain minimal measurement solutions. These solutions are clustered to find subsets that meet the clustering criteria. If all minimal measurement solutions diverge or fail to converge, the CCW method performs a systematic, exhaustive search to identify and exclude unreliable base stations until a valid aggregated class is found or only three stations remain. The final position estimate is the weighted average of the elements in this class, with weights based on the TBSC’s Cramér–Rao lower bound (CRLB). Simulation results show that under unbalanced noise conditions, especially with six and eight base stations, a threshold effect occurs. When the ratio of the abnormal error level to the normal error level exceeds a certain level, the CCW method outperforms other techniques by detecting and removing abnormal measurements, thus improving localization accuracy by focusing on primarily accurate measurements. In real acoustic indoor localization experiments, the CCW method significantly outperformed other methods. In static tests, it achieved sub-0.36 m accuracy for 90% of estimated positions, and in dynamic tests, it closely matched real trajectories with an average anomaly rate of only 1.1%.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-13"},"PeriodicalIF":5.9,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145455782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-29DOI: 10.1109/TIM.2025.3614817
Wei Tian;De Zhang;Shuhao Zhang;Haoran Ji;Lei Wang;Ying Pang;Fei Lan;Jinghua Li
In order to achieve efficient power transmission between the transducer and the power amplifier, and to solve the problem of acoustic wave distortion in the transmission, this article proposes a tunable matrix capacitive impedance matching network (TMCIMN) for the electroacoustic transduction system (ETS). First, the circuit model of the giant magnetostrictive transducer (GMT) was analyzed, and a method for fitting its load impedance was proposed. Subsequently, the TMCIMN topology, working principle, and matching range were introduced. This network implements controlled switching of matrix capacitors across operational frequency bands, enabling wideband efficient power transmission. To solve the amplitude–frequency response distortion in transducer sound waves, a predistortion method based on a finite impulse response (FIR) filter frequency compensation was proposed. This method estimates the system impulse response using an equalization algorithm. The equalizer preprocesses the reference signal to compensate for missing frequency components and suppress excessive ones, thereby improving the sound output linearity. The simulation and experimental results demonstrated that, compared to traditional static impedance matching networks, the proposed method combines dynamic bandwidth matching switching with acoustic distortion compensation capability, achieving over eightfold bandwidth expansion.
{"title":"A Tunable Matrix Capacitive Impedance Matching Network for Electroacoustic Transduction Systems","authors":"Wei Tian;De Zhang;Shuhao Zhang;Haoran Ji;Lei Wang;Ying Pang;Fei Lan;Jinghua Li","doi":"10.1109/TIM.2025.3614817","DOIUrl":"https://doi.org/10.1109/TIM.2025.3614817","url":null,"abstract":"In order to achieve efficient power transmission between the transducer and the power amplifier, and to solve the problem of acoustic wave distortion in the transmission, this article proposes a tunable matrix capacitive impedance matching network (TMCIMN) for the electroacoustic transduction system (ETS). First, the circuit model of the giant magnetostrictive transducer (GMT) was analyzed, and a method for fitting its load impedance was proposed. Subsequently, the TMCIMN topology, working principle, and matching range were introduced. This network implements controlled switching of matrix capacitors across operational frequency bands, enabling wideband efficient power transmission. To solve the amplitude–frequency response distortion in transducer sound waves, a predistortion method based on a finite impulse response (FIR) filter frequency compensation was proposed. This method estimates the system impulse response using an equalization algorithm. The equalizer preprocesses the reference signal to compensate for missing frequency components and suppress excessive ones, thereby improving the sound output linearity. The simulation and experimental results demonstrated that, compared to traditional static impedance matching networks, the proposed method combines dynamic bandwidth matching switching with acoustic distortion compensation capability, achieving over eightfold bandwidth expansion.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-12"},"PeriodicalIF":5.9,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145455785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-16DOI: 10.1109/TIM.2025.3604934
Min-Che Tsai;Chao-Chung Peng
The Mecanum wheel car (MWC) is increasingly becoming the mainstream automated guided vehicle (AGV) in factory automation, replacing traditional transport vehicles due to its flexibility and maneuverability. With its widespread applications, there is a corresponding high demand for system inspection and maintenance policies. However, the estimation of kernel parameters without the system disassembly is less investigated. To solve this problem, this article starts from a framework of nonholonomic constraints and uses the Lagrange equations to derive a complete dynamic model of the MWC. Next, a measurement equation using the signal filtering method (FM) is derived. However, the design of the filtering factors is the key issue of the tradeoff between estimation precision and noise suppression. To effectively solve this design problem, particle swarm optimization (PSO) is used to optimize the filtering factor. The proposed method not only avoids interference from noisy acceleration measurements of the MWC but also significantly improves parameter estimation accuracy. The feasibility of the proposed method was validated through both numerical simulations and experiments. The experimental results demonstrate that the parameter estimation method proposed in this article can accurately estimate the internal parameters of the system, enabling precise prediction of the MWC’s motion behavior.
{"title":"Model-Based Particle Swarm Optimization Filtering Algorithm for Mecanum Wheel Car Parameter Identification With Measurement Noise","authors":"Min-Che Tsai;Chao-Chung Peng","doi":"10.1109/TIM.2025.3604934","DOIUrl":"https://doi.org/10.1109/TIM.2025.3604934","url":null,"abstract":"The Mecanum wheel car (MWC) is increasingly becoming the mainstream automated guided vehicle (AGV) in factory automation, replacing traditional transport vehicles due to its flexibility and maneuverability. With its widespread applications, there is a corresponding high demand for system inspection and maintenance policies. However, the estimation of kernel parameters without the system disassembly is less investigated. To solve this problem, this article starts from a framework of nonholonomic constraints and uses the Lagrange equations to derive a complete dynamic model of the MWC. Next, a measurement equation using the signal filtering method (FM) is derived. However, the design of the filtering factors is the key issue of the tradeoff between estimation precision and noise suppression. To effectively solve this design problem, particle swarm optimization (PSO) is used to optimize the filtering factor. The proposed method not only avoids interference from noisy acceleration measurements of the MWC but also significantly improves parameter estimation accuracy. The feasibility of the proposed method was validated through both numerical simulations and experiments. The experimental results demonstrate that the parameter estimation method proposed in this article can accurately estimate the internal parameters of the system, enabling precise prediction of the MWC’s motion behavior.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-12"},"PeriodicalIF":5.9,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-12DOI: 10.1109/TIM.2025.3609373
Jun Zhang;Liu Tao;Xuan Xie;Bei Huang;Yaya Song;Lihong Dong;Haidou Wang
Fatigue cracks and other forms of damage can have a significant impact on the normal operation of metal facilities, necessitating the deployment of multiple sensors for monitoring within large structures. The arrangement of these sensors must take into account factors such as the shape, size, and complexity of the monitoring area, as well as the optimal positioning and spacing of sensor nodes. This requirement for comprehensive coverage while minimizing costs presents considerable challenges for structural health monitoring (SHM) techniques. In this article, the feasibility of crack detection with a simple microstrip line (ML) is studied in the millimeter-wave band. The detection sensitivity is 0.283/mm2, the precision is 13.61%, and the minimum crack depth that can be identified is 0.2 mm (when crack width $ge 1.0$ mm). An equivalent circuit model for this type of traveling-wave sensor is established in conjunction with field analysis, and the accuracy of the model is verified by comparing full-wave simulation and the circuit model. The proposed sensor can act as a distributed sensor for the SHM applications.
{"title":"Research on Quantitative Circuit Model and Detection of Crack Based on Microstrip Line Structure","authors":"Jun Zhang;Liu Tao;Xuan Xie;Bei Huang;Yaya Song;Lihong Dong;Haidou Wang","doi":"10.1109/TIM.2025.3609373","DOIUrl":"https://doi.org/10.1109/TIM.2025.3609373","url":null,"abstract":"Fatigue cracks and other forms of damage can have a significant impact on the normal operation of metal facilities, necessitating the deployment of multiple sensors for monitoring within large structures. The arrangement of these sensors must take into account factors such as the shape, size, and complexity of the monitoring area, as well as the optimal positioning and spacing of sensor nodes. This requirement for comprehensive coverage while minimizing costs presents considerable challenges for structural health monitoring (SHM) techniques. In this article, the feasibility of crack detection with a simple microstrip line (ML) is studied in the millimeter-wave band. The detection sensitivity is 0.283/mm2, the precision is 13.61%, and the minimum crack depth that can be identified is 0.2 mm (when crack width <inline-formula> <tex-math>$ge 1.0$ </tex-math></inline-formula> mm). An equivalent circuit model for this type of traveling-wave sensor is established in conjunction with field analysis, and the accuracy of the model is verified by comparing full-wave simulation and the circuit model. The proposed sensor can act as a distributed sensor for the SHM applications.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-8"},"PeriodicalIF":5.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-12DOI: 10.1109/TIM.2025.3609375
Lichao Chen;Xiaofeng Ouyang;Fangling Zeng;Yuting Ming;Siyi Han
Global Navigation Satellite System (GNSS) is vulnerable to spoofing attacks due to its open signal structure. Studying spoofing mitigation methods is, therefore, crucial for ensuring the security of GNSS-based services. However, current spoofing mitigation techniques rely on code-phase estimation of multiple correlators or the assistance of external information, which is costly and lacks practicality. Therefore, we propose a new spoofing mitigation method based on code-carrier difference (CCD) for pseudorange (PR) bias estimation and correction. The method effectively leverages the inherent correlation between carrier and code to construct CCD based on phase, which is then converted into PR bias. This enables effective prediction of PR deviations induced by spoofing. Notably, the technique achieves spoofing mitigation without requiring precise estimation of code-phase offset. The results show that the proposed method can effectively reduce the impact of spoofing signals to around 20 m in scenarios with low power advantage, as well as in static/dynamic and time/positioning spoofing scenarios. In the later stage of spoofing, the proposed algorithm reduces the resolution error by up to 97.0% in all scenarios and maintains a stable and smooth position, velocity, and time (PVT) solution performance throughout the whole time period. The proposed algorithm performs well in terms of mitigation effect, accuracy, robustness, and the smoothness of PVT solution, providing GNSS receivers with an efficient, lightweight, and reliable anti-interference solution.
{"title":"GNSS Spoofing Mitigation Based on Code-Carrier Difference Pair Pseudorange Correction","authors":"Lichao Chen;Xiaofeng Ouyang;Fangling Zeng;Yuting Ming;Siyi Han","doi":"10.1109/TIM.2025.3609375","DOIUrl":"https://doi.org/10.1109/TIM.2025.3609375","url":null,"abstract":"Global Navigation Satellite System (GNSS) is vulnerable to spoofing attacks due to its open signal structure. Studying spoofing mitigation methods is, therefore, crucial for ensuring the security of GNSS-based services. However, current spoofing mitigation techniques rely on code-phase estimation of multiple correlators or the assistance of external information, which is costly and lacks practicality. Therefore, we propose a new spoofing mitigation method based on code-carrier difference (CCD) for pseudorange (PR) bias estimation and correction. The method effectively leverages the inherent correlation between carrier and code to construct CCD based on phase, which is then converted into PR bias. This enables effective prediction of PR deviations induced by spoofing. Notably, the technique achieves spoofing mitigation without requiring precise estimation of code-phase offset. The results show that the proposed method can effectively reduce the impact of spoofing signals to around 20 m in scenarios with low power advantage, as well as in static/dynamic and time/positioning spoofing scenarios. In the later stage of spoofing, the proposed algorithm reduces the resolution error by up to 97.0% in all scenarios and maintains a stable and smooth position, velocity, and time (PVT) solution performance throughout the whole time period. The proposed algorithm performs well in terms of mitigation effect, accuracy, robustness, and the smoothness of PVT solution, providing GNSS receivers with an efficient, lightweight, and reliable anti-interference solution.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-16"},"PeriodicalIF":5.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-12DOI: 10.1109/TIM.2025.3609324
Pengxiao Guo;Lei Zhang;Lu Wang;Sajid Ullah;Jianshe Li;Li Huo;Shuguang Li
Global climate change has led to significant fluctuations in ocean salinity and temperature, especially at higher latitudes, which have severely affected natural ecosystems and human production and life. This has placed higher demands on real-time and precise hydrological detection. This article utilizes Ag-based surface plasmon resonance (SPR) optical fiber sensors modulated by TiO2 films of different thicknesses to achieve simultaneous detection of two parameters within a wide temperature range ($- 40~^{circ }$ C to $100~^{circ }$ C) and a wide salinity range (0%–25%). The Ag/thin-layer TiO2 structure used for salinity measurement can effectively enhance the sensitivity of salinity sensing and the oxidation resistance of the Ag film. The Ag/thick-layer TiO2/PDMS composite film structure used for temperature measurement can broaden the refractive index (RI) range and measurement range by enhancing the local electric field and improving the equivalent RI. The integration of PDMS can improve the spectral response and probe stability at low temperatures. The cascaded probe structure enables the simultaneous and distinguishable measurement of the two parameters at different working wavelengths. Experimental results show that the maximum salinity sensitivity is 7.2 nm/% and the maximum temperature sensitivity is 12.8 nm/°C. This study demonstrates the path of using semiconductor thickness modulation to expand the SPR bandwidth and achieve simultaneous sensing of multiple parameters, which avoids the complexity of multimaterial structure integration and the risk of stress cracking. It provides technical reserves for in situ hydrological detection in high-altitude or complex water environments in the future.
全球气候变化导致海洋盐度和温度大幅波动，特别是在高纬度地区，严重影响了自然生态系统和人类生产生活。这就对实时、精确的水文探测提出了更高的要求。本文利用不同厚度TiO2薄膜调制的ag基表面等离子体共振（SPR）光纤传感器，实现了宽温度范围（$- 40~^{circ}$ C ~ $100~^{circ}$ C）和宽盐度范围（0% ~ 25%）两个参数的同时检测。用于盐度测量的Ag/薄层TiO2结构可以有效地提高盐感灵敏度和Ag膜的抗氧化性。用于温度测量的Ag/厚层TiO2/PDMS复合薄膜结构可以通过增强局部电场和提高等效RI来扩大折射率（RI）范围和测量范围。PDMS的集成可以提高探针在低温下的光谱响应和稳定性。级联探头结构可以在不同的工作波长下同时和可区分地测量两个参数。实验结果表明，最大盐度灵敏度为7.2 nm/%，最大温度灵敏度为12.8 nm/℃。本研究展示了利用半导体厚度调制来扩展SPR带宽并实现多参数同时感知的路径，避免了多材料结构集成的复杂性和应力开裂的风险。为今后在高海拔或复杂水环境下的原位水文探测提供了技术储备。
{"title":"TiO2-Modified SPR Fiber-Optic Sensor for High-Sensitivity Salinity and Temperature Detection in Low-Temperature Environments","authors":"Pengxiao Guo;Lei Zhang;Lu Wang;Sajid Ullah;Jianshe Li;Li Huo;Shuguang Li","doi":"10.1109/TIM.2025.3609324","DOIUrl":"https://doi.org/10.1109/TIM.2025.3609324","url":null,"abstract":"Global climate change has led to significant fluctuations in ocean salinity and temperature, especially at higher latitudes, which have severely affected natural ecosystems and human production and life. This has placed higher demands on real-time and precise hydrological detection. This article utilizes Ag-based surface plasmon resonance (SPR) optical fiber sensors modulated by TiO2 films of different thicknesses to achieve simultaneous detection of two parameters within a wide temperature range (<inline-formula> <tex-math>$- 40~^{circ }$ </tex-math></inline-formula>C to <inline-formula> <tex-math>$100~^{circ }$ </tex-math></inline-formula>C) and a wide salinity range (0%–25%). The Ag/thin-layer TiO2 structure used for salinity measurement can effectively enhance the sensitivity of salinity sensing and the oxidation resistance of the Ag film. The Ag/thick-layer TiO2/PDMS composite film structure used for temperature measurement can broaden the refractive index (RI) range and measurement range by enhancing the local electric field and improving the equivalent RI. The integration of PDMS can improve the spectral response and probe stability at low temperatures. The cascaded probe structure enables the simultaneous and distinguishable measurement of the two parameters at different working wavelengths. Experimental results show that the maximum salinity sensitivity is 7.2 nm/% and the maximum temperature sensitivity is 12.8 nm/°C. This study demonstrates the path of using semiconductor thickness modulation to expand the SPR bandwidth and achieve simultaneous sensing of multiple parameters, which avoids the complexity of multimaterial structure integration and the risk of stress cracking. It provides technical reserves for in situ hydrological detection in high-altitude or complex water environments in the future.","PeriodicalId":13341,"journal":{"name":"IEEE Transactions on Instrumentation and Measurement","volume":"74 ","pages":"1-12"},"PeriodicalIF":5.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：