Ionospheric delay, as one of the largest error sources in radio propagation, can only be corrected for this error using the ionospheric delay correction model for Global Navigation Satellite System (GNSS) single-frequency users. In this paper, the 2021 geomagnetic storm event is selected, and based on the measured ionospheric data from the GNSS observatory, the perturbation of the ionosphere by the geomagnetic storm event is analyzed, and it is found that the response of the ionosphere to the geomagnetic storm has obvious differences in the response characteristics and response time in different latitude regions. The performance of the global ionospheric map (GIM), the empirical model, and the broadcast ionospheric model during the geomagnetic storm-induced ionospheric perturbation is analyzed and the change in the accuracy of each ionospheric model during the geomagnetic storm-induced ionospheric perturbation is investigated, using the measured electron content of the GNSS as a benchmark. The results show that there is good agreement between the GIM products and the measured electron content during the period of ionospheric calm and the period of ionospheric perturbation. It is worth noting that geomagnetic storms do not necessarily lead to a decrease in the accuracy of ionospheric delay-correction models, and in some cases, the models that were originally under-accurate show a tendency to improve their accuracy during the period of perturbation instead. Neither the broadcast ionospheric model nor the electron content of the empirical model output responds to geomagnetic storm-induced ionospheric perturbations.
{"title":"Analysis of ionospheric delay correction model performance during geomagnetic storms","authors":"Jialong Liu;Shuli Song;Na Cheng;Yongxing Zhu;Xulei Jin;Chao Huang;Jun Jiang;Hongzhan Zhao","doi":"10.1029/2023RS007803","DOIUrl":"10.1029/2023RS007803","url":null,"abstract":"Ionospheric delay, as one of the largest error sources in radio propagation, can only be corrected for this error using the ionospheric delay correction model for Global Navigation Satellite System (GNSS) single-frequency users. In this paper, the 2021 geomagnetic storm event is selected, and based on the measured ionospheric data from the GNSS observatory, the perturbation of the ionosphere by the geomagnetic storm event is analyzed, and it is found that the response of the ionosphere to the geomagnetic storm has obvious differences in the response characteristics and response time in different latitude regions. The performance of the global ionospheric map (GIM), the empirical model, and the broadcast ionospheric model during the geomagnetic storm-induced ionospheric perturbation is analyzed and the change in the accuracy of each ionospheric model during the geomagnetic storm-induced ionospheric perturbation is investigated, using the measured electron content of the GNSS as a benchmark. The results show that there is good agreement between the GIM products and the measured electron content during the period of ionospheric calm and the period of ionospheric perturbation. It is worth noting that geomagnetic storms do not necessarily lead to a decrease in the accuracy of ionospheric delay-correction models, and in some cases, the models that were originally under-accurate show a tendency to improve their accuracy during the period of perturbation instead. Neither the broadcast ionospheric model nor the electron content of the empirical model output responds to geomagnetic storm-induced ionospheric perturbations.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 7","pages":"1-12"},"PeriodicalIF":1.6,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141711879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Erin H. Lay;Lupe Romero;Michael Peterson;Amitabh Nag;Sonja Behnke;Nikhil Pailoor
The Radio Frequency Sensor (RFS), a new radio frequency lightning detector, was launched into geosynchronous orbit in December 2021, and first collected data in January 2022. RFS is a specialized software-defined radio receiver that detects, records, and reports impulsive broadband radio-frequency (RF) signatures from lightning in the very high frequency (VHF; 30–300 MHz) range. Its vantage point from a Western hemisphere geosynchronous orbit provides unique opportunities to study evolution of RF lightning signatures over the durations of thunderstorms over the Americas and Pacific Ocean. Its overlapping view with the Geostationary Lightning Mappers (GOES-16 & 17) enables additional comparisons between the sources of optical emissions and associated VHF emissions that were not possible with previous sensors. We find that RFS preferentially detects bright VHF signals called transionospheric pulse pairs (trans-ionospheric pulse pairs (TIPPs)). It is estimated that more than 85% of the RFS-detected lightning events are TIPPs. This paper presents initial results from the first year and a half of on-orbit operation.
{"title":"Radio frequency sensor: Very high frequency radio frequency lightning detection in geostationary orbit","authors":"Erin H. Lay;Lupe Romero;Michael Peterson;Amitabh Nag;Sonja Behnke;Nikhil Pailoor","doi":"10.1029/2023RS007931","DOIUrl":"10.1029/2023RS007931","url":null,"abstract":"The Radio Frequency Sensor (RFS), a new radio frequency lightning detector, was launched into geosynchronous orbit in December 2021, and first collected data in January 2022. RFS is a specialized software-defined radio receiver that detects, records, and reports impulsive broadband radio-frequency (RF) signatures from lightning in the very high frequency (VHF; 30–300 MHz) range. Its vantage point from a Western hemisphere geosynchronous orbit provides unique opportunities to study evolution of RF lightning signatures over the durations of thunderstorms over the Americas and Pacific Ocean. Its overlapping view with the Geostationary Lightning Mappers (GOES-16 & 17) enables additional comparisons between the sources of optical emissions and associated VHF emissions that were not possible with previous sensors. We find that RFS preferentially detects bright VHF signals called transionospheric pulse pairs (trans-ionospheric pulse pairs (TIPPs)). It is estimated that more than 85% of the RFS-detected lightning events are TIPPs. This paper presents initial results from the first year and a half of on-orbit operation.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 6","pages":"1-13"},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141398478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elevated duct (EleD) is an abnormal atmospheric refraction structure with a suspended trapped layer. The precise and highly resolved elevated duct-height-based data (EleDH) is crucial for radio communication systems, especially in electromagnetic wave path loss prediction and EleDH-producing systems. However, producing high-resolution EleDH is challenging because of the massive details in the EleDH data. Direct and high-time refinement procedures mostly lead to unrealistic outcomes. The study provides a Dense-Linear convolutional neural network (DLCNN)-based EleDH refinement technique based on the development of statistical downscaling and super-resolution technologies. Additionally, the stack approach is used, and the refining order is taken into consideration to ensure precision in high-time refinement and provide reliable outcomes. To demonstrate the strength of DLCNN in capturing complex internal characteristics of EleDH, a new EleD data set is first funded, which only contains the duct height. From this data set, we use the duct height as the core refinement of the EleD's trapped layer and the thickness of the trapped layer to ensure reliable duct height. Seven super-resolution models are utilized for fair comparisons. The experimental results prove that the DLCNN has the highest refinement performance; also, it obtained excellent generalization capacity, where the minimum and maximum obtained Accuracy(20%), MAE, and RMSE were 85.22% ∓ 88.30%, 36.09 ∓ 45.97 and 8.68 ∓ 10.14, respectively. High-resolution EleDH improves path loss prediction, where the minimum and maximum obtained bias were 2.37 ∓ 9.51 dB.
{"title":"A method for elevated ducts refinement based on convolutional neural network","authors":"Xunyang Zhu;Ke Yan;Liquan Jiang;Ling Tian;Bin Tian","doi":"10.1029/2023RS007789","DOIUrl":"10.1029/2023RS007789","url":null,"abstract":"Elevated duct (EleD) is an abnormal atmospheric refraction structure with a suspended trapped layer. The precise and highly resolved elevated duct-height-based data (EleDH) is crucial for radio communication systems, especially in electromagnetic wave path loss prediction and EleDH-producing systems. However, producing high-resolution EleDH is challenging because of the massive details in the EleDH data. Direct and high-time refinement procedures mostly lead to unrealistic outcomes. The study provides a Dense-Linear convolutional neural network (DLCNN)-based EleDH refinement technique based on the development of statistical downscaling and super-resolution technologies. Additionally, the stack approach is used, and the refining order is taken into consideration to ensure precision in high-time refinement and provide reliable outcomes. To demonstrate the strength of DLCNN in capturing complex internal characteristics of EleDH, a new EleD data set is first funded, which only contains the duct height. From this data set, we use the duct height as the core refinement of the EleD's trapped layer and the thickness of the trapped layer to ensure reliable duct height. Seven super-resolution models are utilized for fair comparisons. The experimental results prove that the DLCNN has the highest refinement performance; also, it obtained excellent generalization capacity, where the minimum and maximum obtained Accuracy(20%), MAE, and RMSE were 85.22% ∓ 88.30%, 36.09 ∓ 45.97 and 8.68 ∓ 10.14, respectively. High-resolution EleDH improves path loss prediction, where the minimum and maximum obtained bias were 2.37 ∓ 9.51 dB.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 6","pages":"1-22"},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141279527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Varuliantor Dear;Mohammad Sigit Arifianto;Prayitno Abadi;Cahyo Purnomo;Asnawi Husin;Adit Kurniawan;I. S. Iskandar
The development of a digital high-frequency (HF) radio communication system requires an ionospheric channel model from the channel impulse response (CIR) measurement. Although the Watterson ionosphere channel model has been available and used for a long time, several CIR measurements have been conducted in all regions of the Earth in an attempt to validate or replace the Watterson channel model with a suitable model for their region. However, only a few CIR measurements were conducted in low-latitude regions, especially over Indonesia. In this study, we develop the CIR measurement system for the near vertical incidence skywave (NVIS) propagation mode over Java Island based on the software defined radio platform to meet low-cost and simple operation requirements. The specification of the system is based on the International Telecommunication Union ionospheric channel characteristic document and increased in order to be able to capture higher values. Results from a 1-week campaign measurement period show the ability of the system to measure the root mean square of time delay within the range of 0.2–1.3 ms and the Doppler shift within the range of 0.7–1.1 Hz in the quiet conditions of the ionosphere. Further measurements will be conducted to obtain a comprehensive ionosphere CIR that is useful for designing the NVIS-HF digital communication in Indonesia, which is located beneath the crest region of an equatorial ionospheric anomaly.
{"title":"Ionospheric channel impulse response measurement system for NVIS propagation mode over Java Island based on low-cost SDR platform","authors":"Varuliantor Dear;Mohammad Sigit Arifianto;Prayitno Abadi;Cahyo Purnomo;Asnawi Husin;Adit Kurniawan;I. S. Iskandar","doi":"10.1029/2023RS007877","DOIUrl":"https://doi.org/10.1029/2023RS007877","url":null,"abstract":"The development of a digital high-frequency (HF) radio communication system requires an ionospheric channel model from the channel impulse response (CIR) measurement. Although the Watterson ionosphere channel model has been available and used for a long time, several CIR measurements have been conducted in all regions of the Earth in an attempt to validate or replace the Watterson channel model with a suitable model for their region. However, only a few CIR measurements were conducted in low-latitude regions, especially over Indonesia. In this study, we develop the CIR measurement system for the near vertical incidence skywave (NVIS) propagation mode over Java Island based on the software defined radio platform to meet low-cost and simple operation requirements. The specification of the system is based on the International Telecommunication Union ionospheric channel characteristic document and increased in order to be able to capture higher values. Results from a 1-week campaign measurement period show the ability of the system to measure the root mean square of time delay within the range of 0.2–1.3 ms and the Doppler shift within the range of 0.7–1.1 Hz in the quiet conditions of the ionosphere. Further measurements will be conducted to obtain a comprehensive ionosphere CIR that is useful for designing the NVIS-HF digital communication in Indonesia, which is located beneath the crest region of an equatorial ionospheric anomaly.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 6","pages":"1-17"},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141495248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zenith tropospheric delay (ZTD) is an important atmospheric parameter in radio-space-geodetic techniques such as Global Navigation Satellite System (GNSS), which is pivotal for GNSS positioning, navigation and meteorology. The Vienna Mapping Function (VMF) data server is a widely utilized source for implementing ZTD, offering two types of models, that is, the empirical one and the discrete one with Grid-wise and Site-wise models. Therefore, to evaluate the accuracy of these models becomes the focus of this article. Specifically, this study investigates their performances in terms of calculation of ZTD, using the hourly values derived from the International GNSS Service data as references. The results show that the root mean square err (RMSE) of the Site-wise, Grid-wise and global pressure and temperature 3 model are 11.71/13.03/38.56 mm, respectively, indicating the discrete model performs generally better than the empirical model, and the Site-wise model is the better of the two discrete models. From the perspective of spatial resolution, the performance of these three models in ZTD calculation shows obvious influences of latitude changes and elevation differences. From the temporal analysis, the accuracy of the discrete model shows differences over different UTC epochs, while the empirical model can only express the seasonal ZTD characteristics with the average RMSE at different epochs being similar, the specifically values are 39.67, 39.26, 39.38 and 39.18 mm at UTC 0:00, 6:00, 12:00 and 18:00, respectively. The histogram and boxplot well indicate the accuracy differences of the three models in different seasons. Additionally, the time series of three models at different latitudes were also explored in this research. These explorations are conducive to the selection of appropriate models for calculating ZTD based on specific requirements.
{"title":"Comparing discrete and empirical troposphere delay models: A global IGS-based evaluation","authors":"Yifan Yao;Fei Yang;Jian Li;Lei Wang;Junxi Zheng;Ruixian Hao;Tairan Xu","doi":"10.1029/2024RS007950","DOIUrl":"10.1029/2024RS007950","url":null,"abstract":"Zenith tropospheric delay (ZTD) is an important atmospheric parameter in radio-space-geodetic techniques such as Global Navigation Satellite System (GNSS), which is pivotal for GNSS positioning, navigation and meteorology. The Vienna Mapping Function (VMF) data server is a widely utilized source for implementing ZTD, offering two types of models, that is, the empirical one and the discrete one with Grid-wise and Site-wise models. Therefore, to evaluate the accuracy of these models becomes the focus of this article. Specifically, this study investigates their performances in terms of calculation of ZTD, using the hourly values derived from the International GNSS Service data as references. The results show that the root mean square err (RMSE) of the Site-wise, Grid-wise and global pressure and temperature 3 model are 11.71/13.03/38.56 mm, respectively, indicating the discrete model performs generally better than the empirical model, and the Site-wise model is the better of the two discrete models. From the perspective of spatial resolution, the performance of these three models in ZTD calculation shows obvious influences of latitude changes and elevation differences. From the temporal analysis, the accuracy of the discrete model shows differences over different UTC epochs, while the empirical model can only express the seasonal ZTD characteristics with the average RMSE at different epochs being similar, the specifically values are 39.67, 39.26, 39.38 and 39.18 mm at UTC 0:00, 6:00, 12:00 and 18:00, respectively. The histogram and boxplot well indicate the accuracy differences of the three models in different seasons. Additionally, the time series of three models at different latitudes were also explored in this research. These explorations are conducive to the selection of appropriate models for calculating ZTD based on specific requirements.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 6","pages":"1-12"},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141397724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tomoe Taki;Satoshi Kurita;Hirotsugu Kojima;Yoshiya Kasahara;Shoya Matsuda;Ayako Matsuoka;Yoichi Kazama;Chae-Woo Jun;Shiang-Yu Wang;Sunny W. Y. Tam;Tzu-Fang Chang;Bo-Jhou Wang;Yoshizumi Miyoshi;Iku Shinohara
We have analyzed Electrostatic Electron Cyclotron Harmonic (ECH) waves observed using interferometry observation mode performed by the Arase satellite to estimate low-energy electron temperatures. Interferometry can be used to calculate velocities, but the Arase satellite can only perform interferometry observations in a one-dimensional direction. We proposed a method to estimate the wave vector of the observed ECH waves from the observed electric fields and calculated the phase velocity for each frequency. We determined the particle parameters from the particle detector and the upper hybrid resonance and estimated the unknown low-energy electron temperature from the agreement between the observed ECH dispersion relation and the theoretical dispersion curves. We performed our analysis for six events and found that the low-energy electron temperature in the observed region is on the order of 1 eV.
{"title":"Cold electron temperature in the inner magnetosphere estimated through the dispersion relation of ECH waves from the Arase satellite observations","authors":"Tomoe Taki;Satoshi Kurita;Hirotsugu Kojima;Yoshiya Kasahara;Shoya Matsuda;Ayako Matsuoka;Yoichi Kazama;Chae-Woo Jun;Shiang-Yu Wang;Sunny W. Y. Tam;Tzu-Fang Chang;Bo-Jhou Wang;Yoshizumi Miyoshi;Iku Shinohara","doi":"10.1029/2023RS007927","DOIUrl":"10.1029/2023RS007927","url":null,"abstract":"We have analyzed Electrostatic Electron Cyclotron Harmonic (ECH) waves observed using interferometry observation mode performed by the Arase satellite to estimate low-energy electron temperatures. Interferometry can be used to calculate velocities, but the Arase satellite can only perform interferometry observations in a one-dimensional direction. We proposed a method to estimate the wave vector of the observed ECH waves from the observed electric fields and calculated the phase velocity for each frequency. We determined the particle parameters from the particle detector and the upper hybrid resonance and estimated the unknown low-energy electron temperature from the agreement between the observed ECH dispersion relation and the theoretical dispersion curves. We performed our analysis for six events and found that the low-energy electron temperature in the observed region is on the order of 1 eV.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 6","pages":"1-10"},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141399064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents the first ever observations on aspect-sensitive characteristics of 205 MHz stratosphere-troposphere (ST) radar located at a tropical station Cochin (10.04°N, 76.3°E) using volume scanning. The most significant and new observation is that the signal-to-noise ratio in zenith and off-zenith beams are nearly equal in some height region, indicating the presence of isotropic turbulence. Signal strength decreases by 0.75 dB per degree from 0 to 10 degree off-zenith, 0.9 dB per degree from 10 to 20 degree off-zenith and 0.3 dB per degree beyond 20 degree off-zenith. Different causative mechanisms are discussed on the basis of various estimated parameters associated with aspect sensitivity. Maximum aspect sensitivity is observed between 12 and 17 km, indicating the presence of dynamic instability arising due to strong wind shear and atmospheric stability. When both the square of wind shear and stability parameters are above 0.25 × 10 −3 s −2 , the scatterers become mostly isotropic. The study also shows a power difference in the symmetric beams as well as azimuth angle dependency. Analysis suggests that this asymmetry is due to the tilting of layers by the action of atmospheric gravity waves generated through Kelvin-Helmholtz instability. The present configuration of radar can provide a better understanding of three-dimensional structures of turbulence and instabilities.
{"title":"Structures and backscattering characteristics of CUSAT 205 MHz stratosphere-troposphere radar at Cochin (10.04°N, 76.3°E)—first results","authors":"Nabarun Poddar;Siddarth Shankar Das;Veenus Venugopal;S. Abhilash;V. Rakesh","doi":"10.1029/2023RS007894","DOIUrl":"10.1029/2023RS007894","url":null,"abstract":"This paper presents the first ever observations on aspect-sensitive characteristics of 205 MHz stratosphere-troposphere (ST) radar located at a tropical station Cochin (10.04°N, 76.3°E) using volume scanning. The most significant and new observation is that the signal-to-noise ratio in zenith and off-zenith beams are nearly equal in some height region, indicating the presence of isotropic turbulence. Signal strength decreases by 0.75 dB per degree from 0 to 10 degree off-zenith, 0.9 dB per degree from 10 to 20 degree off-zenith and 0.3 dB per degree beyond 20 degree off-zenith. Different causative mechanisms are discussed on the basis of various estimated parameters associated with aspect sensitivity. Maximum aspect sensitivity is observed between 12 and 17 km, indicating the presence of dynamic instability arising due to strong wind shear and atmospheric stability. When both the square of wind shear and stability parameters are above 0.25 × 10\u0000<sup>−3</sup>\u0000 s\u0000<sup>−2</sup>\u0000, the scatterers become mostly isotropic. The study also shows a power difference in the symmetric beams as well as azimuth angle dependency. Analysis suggests that this asymmetry is due to the tilting of layers by the action of atmospheric gravity waves generated through Kelvin-Helmholtz instability. The present configuration of radar can provide a better understanding of three-dimensional structures of turbulence and instabilities.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 6","pages":"1-17"},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141404745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Poli;P. Rocca;P. Rosatti;N. Anselmi;M. Salucci;S. Yang;F. Yang;A. Massa
In this paper, the design of a novel horizontally polarized single-layer antenna for 77 (GHz) automotive radar applications is4 addressed. An innovative non-uniform zig-zag parametrization of the antenna layout is considered to enable a more flexible control on both the impedance matching in the working frequency band and the shaping of the radiated beam pattern with respect to a standard (uniform) one without compromising the linear (horizontal) polarization of the radiated field. Such a polarization guarantees a lower back-scattering from road pavements, resulting in a reduced amount of clutter and thus allowing a more robust target detection. Moreover, the single-layer layout has several advantages in terms of fabrication simplicity/costs and mechanical robustness to vibrations. The design of the proposed non-uniform zig-zag antenna (NZA) is performed through a customized implementation of the System-by-Design (SbD) approach that fruitfully combines machine learning and evolutionary optimization to efficiently deal with the computational complexity at hand. An extensive numerical validation, dealing with designs of different lengths, verifies the high performance of the NZA in terms of beam direction deviation (e.g., BDD < 1 (deg)), sidelobe level (e.g., SLL < —18.2 (dB)), and polarization ratio (e.g., PR > 20 (dB)) within the working frequency band H = [76 : 78] (GHz), as well as its superiority over competitive designs. Finally, the realization of a prototype and its experimental test, validate the proposed NZA concept for automotive mm-wave radar applications in advanced driver assistance systems and autonomous vehicles such as, for instance, adaptive cruise control, collision avoidance, and blind spot detection.
{"title":"AI-assisted design of printed edge-fed non-uniform ZigZag antenna for mm-wave automotive radar","authors":"L. Poli;P. Rocca;P. Rosatti;N. Anselmi;M. Salucci;S. Yang;F. Yang;A. Massa","doi":"10.1029/2023RS007912","DOIUrl":"https://doi.org/10.1029/2023RS007912","url":null,"abstract":"In this paper, the design of a novel horizontally polarized single-layer antenna for 77 (GHz) automotive radar applications is4 addressed. An innovative non-uniform zig-zag parametrization of the antenna layout is considered to enable a more flexible control on both the impedance matching in the working frequency band and the shaping of the radiated beam pattern with respect to a standard (uniform) one without compromising the linear (horizontal) polarization of the radiated field. Such a polarization guarantees a lower back-scattering from road pavements, resulting in a reduced amount of clutter and thus allowing a more robust target detection. Moreover, the single-layer layout has several advantages in terms of fabrication simplicity/costs and mechanical robustness to vibrations. The design of the proposed non-uniform zig-zag antenna (NZA) is performed through a customized implementation of the System-by-Design (SbD) approach that fruitfully combines machine learning and evolutionary optimization to efficiently deal with the computational complexity at hand. An extensive numerical validation, dealing with designs of different lengths, verifies the high performance of the NZA in terms of beam direction deviation (e.g., BDD < 1 (deg)), sidelobe level (e.g., SLL < —18.2 (dB)), and polarization ratio (e.g., PR > 20 (dB)) within the working frequency band H = [76 : 78] (GHz), as well as its superiority over competitive designs. Finally, the realization of a prototype and its experimental test, validate the proposed NZA concept for automotive mm-wave radar applications in advanced driver assistance systems and autonomous vehicles such as, for instance, adaptive cruise control, collision avoidance, and blind spot detection.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"59 6","pages":"1-20"},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141495249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rajnish K. Ranjan, Atanu Chowdhury, Dibyendu Ghoshal
The practical applications within the domain of the fifth generation (5G) and the emerging beyond 5G network necessitate a high data transmission rate along with minimal achievable delay. With this objective in focus, the maximum capacity is extensively quantified through the utilization of the delay-constrained effective capacity (EC) technique, which stands in contrast to Shannon's ergodic capacity. The current study is engaged in the analysis of EC within a delay-limited wireless system operating in a double-shadowed Rician (DSR) fading channel. Within this channel, only the Nakagami-m distribution concept has been applied to both the dominant and secondary shadowing components of the proposed network model. A new exact closed-form expression for EC within the DSR fading channel has been derived using the Fox-H function. Furthermore, an analysis has been conducted for both high and low signal-to-noise ratios to provide further insights and explanations for the proposed model. It is worth noting that the results obtained from both simulation and analytical methods exhibit substantial similarity, revealing interdependence among various parameters present in the proposed model.
{"title":"On The Effective Capacity Performance Analysis Over Nakagami-m Distribution-Based Double-Shadowed Rician Fading Channel","authors":"Rajnish K. Ranjan, Atanu Chowdhury, Dibyendu Ghoshal","doi":"10.1029/2023rs007868","DOIUrl":"https://doi.org/10.1029/2023rs007868","url":null,"abstract":"The practical applications within the domain of the fifth generation (5G) and the emerging beyond 5G network necessitate a high data transmission rate along with minimal achievable delay. With this objective in focus, the maximum capacity is extensively quantified through the utilization of the delay-constrained effective capacity (EC) technique, which stands in contrast to Shannon's ergodic capacity. The current study is engaged in the analysis of EC within a delay-limited wireless system operating in a double-shadowed Rician (DSR) fading channel. Within this channel, only the Nakagami-<i>m</i> distribution concept has been applied to both the dominant and secondary shadowing components of the proposed network model. A new exact closed-form expression for EC within the DSR fading channel has been derived using the Fox-H function. Furthermore, an analysis has been conducted for both high and low signal-to-noise ratios to provide further insights and explanations for the proposed model. It is worth noting that the results obtained from both simulation and analytical methods exhibit substantial similarity, revealing interdependence among various parameters present in the proposed model.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"6 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140598971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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