a rectenna designed for wireless power transfer at 900 MHz focuses on conjugate impedance matching and image impedance matching for improved efficiency. To do them, a voltage doubler rectifier circuit (VD) and a planar monopole antenna (PMA) were engineered with the same pure resistance value and integrated into the rectenna. The input impedance of the VD with 30 Ω load resistance indicated a pure resistance of approximately 73 Ω. This value closely matches the input impedance of a dipole antenna operating as a pure resistor. Since the prototype rectifier circuit is unbalanced, the authors constructed a PMA, an unbalanced antenna similar to a dipole antenna, on a double-sided circuit board. In this setup, a microstrip line was created by extending the radiating element, achieving the impedance matchings. Measurements indicated a voltage standing wave ratio of approximately 1.03. A rectenna efficiency of 37.4% was observed for a transmission distance of 50 cm. The rectification efficiency of the VD is nearly 0% when the input power is less than — 20 dBm, and the received power of the PMA is less than — 20 dBm when the transmission distance is 60 cm or more. It is predicted that the rectenna efficiency will be 0% when the transmission distance is 60 cm or more. However, the rectenna efficiency was 24.6% when the transmission distance was 60 cm. This over 20% improvement is due to the connection between the PMA and the VD using pure resistance.
{"title":"A prototype of a 900 MHz band integrated rectenna by using a planar monopole antenna with feeder","authors":"N. Nakashima;T. Sumiyoshi","doi":"10.1029/2024RS008022","DOIUrl":"https://doi.org/10.1029/2024RS008022","url":null,"abstract":"a rectenna designed for wireless power transfer at 900 MHz focuses on conjugate impedance matching and image impedance matching for improved efficiency. To do them, a voltage doubler rectifier circuit (VD) and a planar monopole antenna (PMA) were engineered with the same pure resistance value and integrated into the rectenna. The input impedance of the VD with 30 Ω load resistance indicated a pure resistance of approximately 73 Ω. This value closely matches the input impedance of a dipole antenna operating as a pure resistor. Since the prototype rectifier circuit is unbalanced, the authors constructed a PMA, an unbalanced antenna similar to a dipole antenna, on a double-sided circuit board. In this setup, a microstrip line was created by extending the radiating element, achieving the impedance matchings. Measurements indicated a voltage standing wave ratio of approximately 1.03. A rectenna efficiency of 37.4% was observed for a transmission distance of 50 cm. The rectification efficiency of the VD is nearly 0% when the input power is less than — 20 dBm, and the received power of the PMA is less than — 20 dBm when the transmission distance is 60 cm or more. It is predicted that the rectenna efficiency will be 0% when the transmission distance is 60 cm or more. However, the rectenna efficiency was 24.6% when the transmission distance was 60 cm. This over 20% improvement is due to the connection between the PMA and the VD using pure resistance.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130258","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}
Sukanth Karapakula;Christiaan Brinkerink;Antonio Vecchio;Hamid R. Pourshaghaghi;Peter Dolron;Roel Jordans;Eric Bertels;Gerard Aalbers;Mark Ruiter;Albert J. Boonstra;Mark Bentum;David Prinsloo;Michel Arts;Jeanette Bast;Sieds Damstra;Albert van Duin;Nico Ebbendorf;Hans van der Marel;Juergen Morawietz;Roel Witvers;Wietse Poiesz;Rico van Dongen;Baptiste Cecconi;Philippe Zarka;Moustapha Dekkali;Linjie Chen;Mingyuan Wang;Mo Zhang;Maohai Huang;Yihua Yan;Liang Dong;Baolin Tan;Lihua Zhang;Liang Xiong;Ji Sun;Hongbo Zhang;Jinsong Ping;Marc Klein Wolt;Heino Falcke
The Netherlands-China Low-Frequency Explorer (NCLE) (Boonstra et al., 2017, https://www. ursi.org/proceedings/procGA17/papers/Paper_J19-2(1603).pdf; Chen et al., 2020, https://ui.adsabs.harvard.edu/abs/2020AAS...23610203C/abstract) is a radio instrument for astrophysical studies in the low-frequency range (80 kHz-80 MHz). As a technology demonstrator, NCLE shall inform the design of future radio receivers that aim at low-frequency radio astronomy. NCLE can make observations at very high spectral resolution (<1 kHz) and generate radio sky maps at an angular resolution of ≈1.5 radians. NCLE uses three monopole antennas, each 5 m long, and three identical analog signal chains to process the signal from each antenna. A single digital receiver samples the signal and calculates the auto-correlated and cross-correlated spectra. The instrument's analog and digital signal chains are extensively configurable. They can be fine-tuned to produce broadband spectra covering the instrument's complete operating frequency range or sub-bands. NCLE was developed within a veryshort timescale of 2 years, and currently, it is on board Queqiao, the relay spacecraft of the Chang'e-4 mission, in a halo orbit around the Earth-Moon L2 point. This paper outlines the science cases, instrument architecture with focus on the signal chain, and discusses the laboratory measurements during the pre-launch phase.
{"title":"Architecture design and ground performance of Netherlands-China low-frequency explorer","authors":"Sukanth Karapakula;Christiaan Brinkerink;Antonio Vecchio;Hamid R. Pourshaghaghi;Peter Dolron;Roel Jordans;Eric Bertels;Gerard Aalbers;Mark Ruiter;Albert J. Boonstra;Mark Bentum;David Prinsloo;Michel Arts;Jeanette Bast;Sieds Damstra;Albert van Duin;Nico Ebbendorf;Hans van der Marel;Juergen Morawietz;Roel Witvers;Wietse Poiesz;Rico van Dongen;Baptiste Cecconi;Philippe Zarka;Moustapha Dekkali;Linjie Chen;Mingyuan Wang;Mo Zhang;Maohai Huang;Yihua Yan;Liang Dong;Baolin Tan;Lihua Zhang;Liang Xiong;Ji Sun;Hongbo Zhang;Jinsong Ping;Marc Klein Wolt;Heino Falcke","doi":"10.1029/2023RS007906","DOIUrl":"https://doi.org/10.1029/2023RS007906","url":null,"abstract":"The Netherlands-China Low-Frequency Explorer (NCLE) (Boonstra et al., 2017, https://www. ursi.org/proceedings/procGA17/papers/Paper_J19-2(1603).pdf; Chen et al., 2020, https://ui.adsabs.harvard.edu/abs/2020AAS...23610203C/abstract) is a radio instrument for astrophysical studies in the low-frequency range (80 kHz-80 MHz). As a technology demonstrator, NCLE shall inform the design of future radio receivers that aim at low-frequency radio astronomy. NCLE can make observations at very high spectral resolution (<1 kHz) and generate radio sky maps at an angular resolution of ≈1.5 radians. NCLE uses three monopole antennas, each 5 m long, and three identical analog signal chains to process the signal from each antenna. A single digital receiver samples the signal and calculates the auto-correlated and cross-correlated spectra. The instrument's analog and digital signal chains are extensively configurable. They can be fine-tuned to produce broadband spectra covering the instrument's complete operating frequency range or sub-bands. NCLE was developed within a veryshort timescale of 2 years, and currently, it is on board Queqiao, the relay spacecraft of the Chang'e-4 mission, in a halo orbit around the Earth-Moon L2 point. This paper outlines the science cases, instrument architecture with focus on the signal chain, and discusses the laboratory measurements during the pre-launch phase.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130281","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}
In this study, a wideband circularly polarized (CP) H-plane horn antenna based on Gap Waveguide (GW) technology in K-band is presented. The proposed antenna consists of two unconnected metal planes. To produce broadband CP radiation, two main methods are utilized. First, two antipodal tapered plates (ATPs) are added in front of the horn. The ATPs are carefully designed for dissimilar polarization orientations. By this technique, the orthogonal electric fields can be prepared. Then, by embedding three metal square pins near the center of the aperture in both inner plates, the impedance bandwidth (BW) and BW of CP radiation of the proposed horn is entirely improved. Its BW for target |S 11 | < —10 dB is 18—28 GHz. Also, the peak gain fluctuates between 11.5 and 13 dB. This antenna can provide a 3 dB polarization axial-ratio BW of about 28.5% (20–26 GHz). Total radiation efficiency is higher than 94%. To verify the design, the proposed structure is manufactured and tested. The proposed horn antenna result has an appropriate agreement between measurement and simulation. Its miniaturized dimensions, easy and cheap fabrication, and broadband CP capability make it a proper volunteer for broadband communication systems.
本研究提出了一种基于间隙波导（GW）技术的 K 波段宽带圆极化（CP）H 平面喇叭天线。该天线由两个未连接的金属平面组成。为了产生宽带 CP 辐射，主要采用了两种方法。首先，在喇叭前面增加了两个对顶锥形板（ATP）。ATP 经过精心设计，具有不同的极化方向。通过这种技术，可以制备正交电场。然后，通过在两块内板上靠近孔径中心的位置嵌入三个金属方针，完全改善了拟建喇叭的阻抗带宽（BW）和 CP 辐射带宽。当目标 |S11| < -10 dB 时，其 BW 为 18-28 GHz。此外，峰值增益在 11.5 和 13 dB 之间波动。该天线可提供约 28.5% （20-26 GHz）的 3 dB 极化轴向比频带宽度。总辐射效率高于 94%。为了验证设计，对所提出的结构进行了制造和测试。所提议的喇叭天线的测量结果与模拟结果之间具有适当的一致性。其微型化的尺寸、简便廉价的制造工艺和宽带 CP 能力使其成为宽带通信系统的理想选择。
{"title":"Miniaturized, broadband, circular polarized horn antenna with Groove gap waveguide technology","authors":"Amir Hossein Haghparast;Pejman Rezaei","doi":"10.1029/2024RS007965","DOIUrl":"https://doi.org/10.1029/2024RS007965","url":null,"abstract":"In this study, a wideband circularly polarized (CP) H-plane horn antenna based on Gap Waveguide (GW) technology in K-band is presented. The proposed antenna consists of two unconnected metal planes. To produce broadband CP radiation, two main methods are utilized. First, two antipodal tapered plates (ATPs) are added in front of the horn. The ATPs are carefully designed for dissimilar polarization orientations. By this technique, the orthogonal electric fields can be prepared. Then, by embedding three metal square pins near the center of the aperture in both inner plates, the impedance bandwidth (BW) and BW of CP radiation of the proposed horn is entirely improved. Its BW for target |S\u0000<inf>11</inf>\u0000| < —10 dB is 18—28 GHz. Also, the peak gain fluctuates between 11.5 and 13 dB. This antenna can provide a 3 dB polarization axial-ratio BW of about 28.5% (20–26 GHz). Total radiation efficiency is higher than 94%. To verify the design, the proposed structure is manufactured and tested. The proposed horn antenna result has an appropriate agreement between measurement and simulation. Its miniaturized dimensions, easy and cheap fabrication, and broadband CP capability make it a proper volunteer for broadband communication systems.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130306","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}
Jia Tan;Haidong Xie;Xiaoying Zhang;Nan Ji;Haihua Liao;ZuGuo Yu;Xueshuang Xiang;Naijin Liu
Deep learning is applied to many complex tasks in the field of wireless communication, such as modulation recognition of spectrum waveforms, because of its convenience and efficiency. This leads to the problem of a malicious third party using a deep learning model to easily recognize the modulation format of the transmitted waveform. Some existing works address this problem directly using the concept of adversarial examples in the computer vision field without fully considering the characteristics of the waveform transmission in the physical world. Therefore, we propose two low-interception waveforms (LIWs) generation methods, the LIW and ULIW algorithms, which can reduce the probability of the modulation being recognized by a third party without affecting the reliable communication of the friendly party. Among them, ULIW improves LIW algorithm by simulating channel noise during training cycle, and substantially reduces the perturbation magnitude while maintaining low interception accuracy. Our LIW and ULIW exhibit significant low-interception performance in both numerical simulations and hardware experiments.
{"title":"Low-interception waveforms: To prevent the recognition of spectrum waveform modulation via adversarial examples","authors":"Jia Tan;Haidong Xie;Xiaoying Zhang;Nan Ji;Haihua Liao;ZuGuo Yu;Xueshuang Xiang;Naijin Liu","doi":"10.1029/2022RS007486","DOIUrl":"https://doi.org/10.1029/2022RS007486","url":null,"abstract":"Deep learning is applied to many complex tasks in the field of wireless communication, such as modulation recognition of spectrum waveforms, because of its convenience and efficiency. This leads to the problem of a malicious third party using a deep learning model to easily recognize the modulation format of the transmitted waveform. Some existing works address this problem directly using the concept of adversarial examples in the computer vision field without fully considering the characteristics of the waveform transmission in the physical world. Therefore, we propose two low-interception waveforms (LIWs) generation methods, the LIW and ULIW algorithms, which can reduce the probability of the modulation being recognized by a third party without affecting the reliable communication of the friendly party. Among them, ULIW improves LIW algorithm by simulating channel noise during training cycle, and substantially reduces the perturbation magnitude while maintaining low interception accuracy. Our LIW and ULIW exhibit significant low-interception performance in both numerical simulations and hardware experiments.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130260","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}
Today, wireless communication systems need an antenna with a high gain, efficiency and beamsteering, as well as broadband capability, especially important in radar communications. The array antenna is commonly used in many applications due to its advantages, such as high gain and wide bandwidth. This paper presents an advanced design of a horizontally steerable planar antenna array intended for significant radar applications. A novel structure is used to create a compact array antenna of 8 × 3 elements. The design features a comprehensive 60° steering sector alongside a notable 12% bandwidth (4.45—5.42 GHz), using 8 × 3 planar array in an novel configuration. A three-element series-fed vertical array is utilized, employing aperture feeds with precisely sized patches to maximize performance. A detailed description of the design and refinement process of this array is presented, with emphasis on its exceptional capabilities for horizontal steering and bandwidth efficiency. By employing series-fed vertical arrays with variable patch dimensions, we have successfully developed an antenna array that meets the stringent bandwidth requirements essential for radar technology, thereby enhancing the operational versatility of radar systems.
{"title":"Optimizing radar functionality: Development of a steerable patch antenna array with enhanced bandwidth","authors":"Mubarak Alanazi;Aladdin Assisi","doi":"10.1029/2024RS008004","DOIUrl":"https://doi.org/10.1029/2024RS008004","url":null,"abstract":"Today, wireless communication systems need an antenna with a high gain, efficiency and beamsteering, as well as broadband capability, especially important in radar communications. The array antenna is commonly used in many applications due to its advantages, such as high gain and wide bandwidth. This paper presents an advanced design of a horizontally steerable planar antenna array intended for significant radar applications. A novel structure is used to create a compact array antenna of 8 × 3 elements. The design features a comprehensive 60° steering sector alongside a notable 12% bandwidth (4.45—5.42 GHz), using 8 × 3 planar array in an novel configuration. A three-element series-fed vertical array is utilized, employing aperture feeds with precisely sized patches to maximize performance. A detailed description of the design and refinement process of this array is presented, with emphasis on its exceptional capabilities for horizontal steering and bandwidth efficiency. By employing series-fed vertical arrays with variable patch dimensions, we have successfully developed an antenna array that meets the stringent bandwidth requirements essential for radar technology, thereby enhancing the operational versatility of radar systems.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130282","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 study provides the design and demonstration of a Ku/K band horn-fed linear polarization (LP) to circular polarization (CP) converter using a reflectarray antenna based on the holographic technique and the generalized law of total reflection without any iterative algorithms. The proposed hologram performs wide-range frequency beam scanning with minimum gain losses and cross-polarization levels. It comprises 2,500 diagonal slotted octagonal subwavelength metasurfaces with a periodicity of 0.266λ 0 = 4 mm at 20 GHz as the center frequency. Two equations are defined to compute Y 11 of the proposed unit cell regarding its dimensions for TE(0,0) and TM(0,0) Floquet modes. They significantly simplify the coding procedure and reduce the computational time for synthesizing the hologram. The antenna is simulated using the CST software from 14 to 25 GHz. As a confirmation, a prototype is manufactured and measured at 16, 18, 20, 22, and 24 GHz to verify its performance. The simulated and measured results are well-matched. The presented hologram achieves 40% 1.8-dB axial ratio (AR) bandwidth (16–25 GHz), 40% 3.3-dB gain bandwidth (16–24 GHz), and above 30% 2-dB gain bandwidth (16–22 GHz). Moreover, the antenna can perform beam scanning from 42° to 24° by changing the frequency from 16 to 24 GHz with peak gain values greater than 20.33 dBi. The LHCP pencil beams are at least 24° off-broadside, so the proposed hologram avoids the feed blockage. These achievements make the hologram one of the best candidates for satellite communications, radar applications, short-range communication, and point-to-point communication.
{"title":"Wideband LP to CP converter using a reflectarray based on modulated admittance surfaces capable of wide-range beam-scanning for Ku/K band applications","authors":"Hamid Tahermanesh;Mohammad Sadegh Abrishamian;Zahra Ghattan Kashani;Mahdi Salehi","doi":"10.1029/2023RS007881","DOIUrl":"https://doi.org/10.1029/2023RS007881","url":null,"abstract":"This study provides the design and demonstration of a Ku/K band horn-fed linear polarization (LP) to circular polarization (CP) converter using a reflectarray antenna based on the holographic technique and the generalized law of total reflection without any iterative algorithms. The proposed hologram performs wide-range frequency beam scanning with minimum gain losses and cross-polarization levels. It comprises 2,500 diagonal slotted octagonal subwavelength metasurfaces with a periodicity of 0.266λ\u0000<inf>0</inf>\u0000 = 4 mm at 20 GHz as the center frequency. Two equations are defined to compute Y\u0000<inf>11</inf>\u0000 of the proposed unit cell regarding its dimensions for TE(0,0) and TM(0,0) Floquet modes. They significantly simplify the coding procedure and reduce the computational time for synthesizing the hologram. The antenna is simulated using the CST software from 14 to 25 GHz. As a confirmation, a prototype is manufactured and measured at 16, 18, 20, 22, and 24 GHz to verify its performance. The simulated and measured results are well-matched. The presented hologram achieves 40% 1.8-dB axial ratio (AR) bandwidth (16–25 GHz), 40% 3.3-dB gain bandwidth (16–24 GHz), and above 30% 2-dB gain bandwidth (16–22 GHz). Moreover, the antenna can perform beam scanning from 42° to 24° by changing the frequency from 16 to 24 GHz with peak gain values greater than 20.33 dBi. The LHCP pencil beams are at least 24° off-broadside, so the proposed hologram avoids the feed blockage. These achievements make the hologram one of the best candidates for satellite communications, radar applications, short-range communication, and point-to-point communication.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130259","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}
Aaron C. Meyer;Daniel J. Breton;Matthew J. Kamrath;Sergey N. Vecherin
The urban radio-frequency (RF) noise generated by our cities continues to change with time. Although models exist to describe the RF noise as functions of frequency and urban land use types, very few models describe the spatial character or structure of the noise on the scales of city blocks (50–150 m). The goal of this work is to investigate the connection between urban morphology and the higher-order spatial statistics of the noise field. To achieve this goal, a large measurement campaign was conducted in Boston, Massachusetts. Many spatial measurements allowed for calculation of spatial correlation functions of noise power in three different neighborhoods, which were used to quantify the spatial structure of the fields. A statistical point source model is then developed, with adjustable parameters relating to urban morphology. Good agreement between the model and the experimental correlation functions suggests the 25 MHz urban noise field is well described by a random network of fixed point sources, radiating with a 1/r power law behavior.
{"title":"Spatial structure of the radio-frequency noise field in a large city","authors":"Aaron C. Meyer;Daniel J. Breton;Matthew J. Kamrath;Sergey N. Vecherin","doi":"10.1029/2023RS007909","DOIUrl":"10.1029/2023RS007909","url":null,"abstract":"The urban radio-frequency (RF) noise generated by our cities continues to change with time. Although models exist to describe the RF noise as functions of frequency and urban land use types, very few models describe the spatial character or structure of the noise on the scales of city blocks (50–150 m). The goal of this work is to investigate the connection between urban morphology and the higher-order spatial statistics of the noise field. To achieve this goal, a large measurement campaign was conducted in Boston, Massachusetts. Many spatial measurements allowed for calculation of spatial correlation functions of noise power in three different neighborhoods, which were used to quantify the spatial structure of the fields. A statistical point source model is then developed, with adjustable parameters relating to urban morphology. Good agreement between the model and the experimental correlation functions suggests the 25 MHz urban noise field is well described by a random network of fixed point sources, radiating with a 1/r power law behavior.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141839410","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}
The ground-based microwave radiometer (MWR) retrieves atmospheric profiles with a high temporal resolution for temperature and relative humidity up to a height of 10 km. These profiles have been widely used in the field of meteorological observation. Due to the inherent fragility of neural networks, one of the important issues in this field is to improve the reliability and stability of MWR profiles based on neural network inversion. We propose a deep learning method that adds noise to the BP neural network inversion (NBPNN) process. Comparison of the radiosonde data and NBPNN results shows that if the error of MWR brightness temperature is in the range of − 2−2 K, the root-mean-square error (RMSE) of the temperature profile is 2.15 K, and the RMSE of the relative humidity profile is 19.46 % inverted by NBPNN. The results are much less than the errors of the temperature profile and relative humidity profile inverted by the traditional backpropagation neural network inverse method. From the comparison, we demonstrated that NBPNN significantly increases the inversion accuracy and robustness under the condition of errors in brightness temperature, which can reduce requirements for BT accuracy of MWR and achieve MWR long-term stability.
{"title":"The robustness of an anti-noise BP neural network inversion algorithm for ground-based microwave radiometer","authors":"Shijie Sun;Huaqiao Gui;Haihe Jiang;Tingqing Cheng","doi":"10.1029/2023RS007941","DOIUrl":"10.1029/2023RS007941","url":null,"abstract":"The ground-based microwave radiometer (MWR) retrieves atmospheric profiles with a high temporal resolution for temperature and relative humidity up to a height of 10 km. These profiles have been widely used in the field of meteorological observation. Due to the inherent fragility of neural networks, one of the important issues in this field is to improve the reliability and stability of MWR profiles based on neural network inversion. We propose a deep learning method that adds noise to the BP neural network inversion (NBPNN) process. Comparison of the radiosonde data and NBPNN results shows that if the error of MWR brightness temperature is in the range of − 2−2 K, the root-mean-square error (RMSE) of the temperature profile is 2.15 K, and the RMSE of the relative humidity profile is 19.46 % inverted by NBPNN. The results are much less than the errors of the temperature profile and relative humidity profile inverted by the traditional backpropagation neural network inverse method. From the comparison, we demonstrated that NBPNN significantly increases the inversion accuracy and robustness under the condition of errors in brightness temperature, which can reduce requirements for BT accuracy of MWR and achieve MWR long-term stability.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141714228","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}
Spacecraft-to-spacecraft radio occultations experiments are being conducted at Mars between Mars Express (MEX) and Trace Gas Orbiter (TGO), the first ever extensive inter-spacecraft occultations at a planet other than Earth. Here we present results from the first 83 such occultations, conducted between 2 Nov 2020 and 5th of July 2023. Of these, 44 observations have to-date resulted in the extraction of vertical electron density profiles. These observations are the successful results of a major feasibility study conducted by the European Space Agency to use pre-existing relay communication equipment for radio science purposes. Mutual radio occultations have numerous advantages over traditional spacecraft-to-ground station occultations. In this work, we demonstrate how raw data are transformed into electron density values and validated with models and other instruments.
{"title":"First results of Mars Express—ExoMars trace gas orbiter mutual radio occultation","authors":"Jacob Parrott;Håkan Svedhem;Olivier Witasse;Colin Wilson;Ingo Müller-Wodarg;Alejandro Cardesín-Moinelo;Peter Schmitz;James Godfrey;Olivier Reboud;Bernhard Geiger;Beatriz Sánchez-Cano;Bruno Nava;Yenca Migoya-Orué","doi":"10.1029/2023RS007873","DOIUrl":"10.1029/2023RS007873","url":null,"abstract":"Spacecraft-to-spacecraft radio occultations experiments are being conducted at Mars between Mars Express (MEX) and Trace Gas Orbiter (TGO), the first ever extensive inter-spacecraft occultations at a planet other than Earth. Here we present results from the first 83 such occultations, conducted between 2 Nov 2020 and 5th of July 2023. Of these, 44 observations have to-date resulted in the extraction of vertical electron density profiles. These observations are the successful results of a major feasibility study conducted by the European Space Agency to use pre-existing relay communication equipment for radio science purposes. Mutual radio occultations have numerous advantages over traditional spacecraft-to-ground station occultations. In this work, we demonstrate how raw data are transformed into electron density values and validated with models and other instruments.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141707322","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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