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Algorithms and statistical analysis for linear structured weighted total least squares problem

Geodesy and Geodynamics 2024年第2期15卷 177-188页

作者： Jian Xie Tianwei Qiu Cui Zhou Dongfang Lin Sichun Long School of Earth Science and spatial information Engineering Hunan University of Science and TechnologyXiangtan 411201China College of Science Central South University of Forestry and TechnologyChangsha 410018China National-Local Joint Engineering Laboratory of Geo-spatial information Technology Hunan University of Science and TechnologyXiangtan 411201China

Weighted total least squares(WTLS)have been regarded as the standard tool for the errors-in-variables(EIV)model in which all the elements in the observation vector and the coefficient matrix are contaminated with random ***,in many geodetic applications,some elements are error-free and some random observations appear repeatedly in different positions in the augmented coefficient *** is called the linear structured EIV(LSEIV)*** kinds of methods are proposed for the LSEIV model from functional and stochastic *** the one hand,the functional part of the LSEIV model is modified into the errors-in-observations(EIO)*** the other hand,the stochastic model is modified by applying the Moore-Penrose inverse of the cofactor *** algorithms are derived through the Lagrange multipliers method and linear *** estimation principles and iterative formula of the parameters are proven to be *** first-order approximate variance-covariance matrix(VCM)of the parameters is also derived.A numerical example is given to compare the performances of our proposed three algorithms with the STLS ***,the least squares(LS),total least squares(TLS)and linear structured weighted total least squares(LSWTLS)solutions are compared and the accuracy evaluation formula is proven to be feasible and ***,the LSWTLS is applied to the field of deformation analysis,which yields a better result than the traditional LS and TLS estimations.

关键词： Linear structured weighted total least squares Errors-in-variables Errors-in-observations Functional modelmodification Stochastic model modification Accuracyevaluation

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Analysis of phase preservation and interferometric offset test in sparse SAR imaging

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Science China(information Sciences) 2024年第2期67卷 219-231页

作者： Zhongqiu XU Bingchen ZHANG Guangzuo LI Xueli ZHAN Yanfei BAO Yirong WU Key Laboratory of spatial information Processing and Application System Technology Chinese Academy of Sciences Aerospace information Research Institute Chinese Academy of Sciences School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of Sciences PLA Academy of Military Sciences

Sparse synthetic aperture radar(SAR) imaging has emerged as a reliable microwave imaging scheme in the recent decade and excels in down-sampling reconstruction and full-sampling performance improvements such as noise, sidelobe, speckle, and ambiguity suppression. To utilize complex image products of sparse reconstruction for improvement in polarimetric, interferometric, and tomographic SAR imaging, it is necessary to evaluate the phase preservation of sparse SAR imaging. In this study, we first introduce the general alternating direction method of multipliers(ADMM) as the universal framework for sparse reconstruction algorithms and adopt chirp scaling algorithm(CSA)-based azimuth-range decouple operators to avoid expensive data storage and processing. Further, we theoretically analyze the phase preservation of the sparse reconstruction algorithm through a comparison with the reconstruction results of CSA. Finally,we conduct the interferometric offset test on the sparse reconstruction results of simulated and real Gaofen-3(GF-3) SAR data, demonstrating the phase-preserving ability of sparse methods.

关键词： sparse SAR imaging phase preservation interferometric offset test general ADMM azimuth-range decouple

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Ultra-highly sensitive dual gases detection based on photoacoustic spectroscopy by exploiting a long-wave,high-power,wide-tunable,singlelongitudinal-mode solid-state laser

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Light(Science & Applications) 2024年第5期13卷 941-956页

作者： Shunda Qiao Ying He Haiyue Sun Pietro Patimisco Angelo Sampaolo Vincenzo Spagnolo Yufei Ma National Key Laboratory of Laser spatial information Harbin Institute of TechnologyHarbinChina PolySense Lab Dipartimento Interateneo di FisicaUniversity and Politecnico of BariVia AmendolaBariItaly

Photoacoustic spectroscopy(PAS)as a highly sensitive and selective trace gas detection technique has extremely broad application in many ***,the laser sources currently used in PAS limit the sensing *** to diode laser and quantum cascade laser,the solid-state laser has the merits of high optical power,excellent beam quality,and wide tuning *** we present a long-wave,high-power,wide-tunable,singlelongitudinal-mode solid-state laser used as light source in a PAS sensor for trace gas *** self-built solid-state laser had an emission wavelength of~2μm with Tm:YAP crystal as the gain material,with an excellent wavelength and optical power stability as well as a high beam *** wide wavelength tuning range of 9.44 nm covers the absorption spectra of water and ammonia,with a maximum optical power of~130 mW,allowing dual gas detection with a single laser *** solid-state laser was used as light source in three different photoacoustic detection techniques:standard PAS with microphone,and external-and intra-cavity quartz-enhanced photoacoustic spectroscopy(QEPAS),proving that solid-state laser is an attractive excitation source in photoacoustic spectroscopy.

关键词： power tunable tuning

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Study on the vertical deformations induced by terrestrial water storage changes in Huang-Huai-Hai river basin

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Geodesy and Geodynamics 2024年第4期15卷 352-365页

作者： Liansheng Deng Yugang Xiao Qusen Chen Feifei Liao Zhao Li School of Electrical and Electronic information Engineering Hubei Polytechnic UniversityHuangshi 435003China Hubei Luojia Laboratory GNSS Research CenterWuhan UniversityWuhan 430079.China Changjiang spatial information Technology Engineering Co. Ltd.Wuhan 430010China

Terrestrial water storage(TWs)variations are associated with water mass movements,which may cause the deformation displacements of the Global Navigation Satellite System(GNSS)*** study investigates the spatio-temporal Tws variations and addresses the relationship between deformation variations observed in the Huang-Huai-Hai River Basin(HHHRB)and local hydrological *** indicate that the vertical velocities at the GNSS stations induced by TWS changes are relatively small,and the impacts of the terrestrial water storage changes are mainly reflected in the changes of seasonal *** there is a downward TWS trend from 2011 to 2022 in most HHHRB areas,velocities from the vertical displacements of both Gravity Recovery and Climate Experiment(GRACE)and GRACE Follow-On(GFO)and the GNSS reflect that the HHHRB is undergoing an uplift process,while the magnitude of the GRACE/GFO derived velocities is much smaller than that of the GNSS *** hydrological deformations estimated from GRACE/GFO and GNSS measurements reveal that the TWS-derived displacements can explain 54.5%of the GNSS seasonal variations,with the phases of terrestrial water storage advancing by about one month relative to GNss common signal ***,the decrease of the groundwater storage in the HHHRB has been accelerating since *** reaching its lowest level around mid-2020,it began to rise rapidly,which might be closely related to the implementation of the South-North Water Transfer Central Project.

关键词： Terrestrial waterstorage GRACE GNSS Vertical deformations Huang-Huai-Hairiverbasin

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Exploring the Spatiotemporal Changes and Driving Forces of Ecosystem Services of Zhejiang Coasts,China,Under Sustainable Development Goals

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Chinese Geographical Science 2024年第4期34卷 647-661页

作者： ZHANG Shu SUN Chao ZHANG Yixin HU Ming SHEN Xingru Department of Geography and spatial information Techniques Ningbo UniversityNingbo 315211China Donghai Academy Ningbo UniversityNingbo 315211China Zhejiang Collaborative Innovation Center&Ningbo Universities Collaborative Innovation Center for Land and Marine spatial Utilization and Governance Research Ningbo UniversityNingbo 315211China Xiangshan High School Ningbo 315700China

Ecosystem services(ESs)refer to the continuous provisioning of ecosystem goods and services that benefit human *** recent decades,rapid urbanization has exerted significant pressure on coastal ecosystems,resulting in biodiversity and habitat loss,environmental pollution,and the depletion of natural *** response to these environmental challenges,the Sustainable Development Goals(SDGs)were *** the pressing need to address these issues,understanding the changes in ESs under the SDGs is crucial for formulating specific ecological *** this study,we first analyzed land use and cover change in the Zhejiang coasts of China during 2000–***,we investigated the spatiotemporal configuration of ESs by integrating carbon storage(CS),soil retention(SR),habitat quality(HQ)and water yield(WY)using the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)*** driving mechanisms of ESs,which varied by space and time,were also explored using the Geo-detector *** results revealed that,over the past two decades:1)the Zhejiang coasts have experienced a significant increase of 2783.72 km^(2) in built-up land areas and a continuous decrease in farmland areas due to rapid urbanization;2)owing to higher precipitation,extensive vegetation cover,and reduced anthropogenic disturbances,forests emerge as a crucial land use type for maintaining ecosystem services such as HQ,CS,WY,and SR;3)ESs have generally declined across the entire Zhejiang coasts,with a significant decrease observed in the northern areas and an increase in the southern areas spatially;4)the expansion of built-up land areas emerged as the primary factor affecting ecosystem services,while the vegetation factor has been increasingly significant and is expected to become predominant in the near *** study provides insights of understanding of ecosystem service theory and emphasizing the importance of preserving biodiversity for long-term sustainable development

关键词： ecosystem services(ESs) Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model Geo-detector land use and cover change(LUCC) Zhejiang coasts China

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Methods for ice velocity mapping in West Antarctica using historical optical satellite images

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Advances in Polar Science 2024年第2期35卷 252-263页

作者： ZHANG Yujie AN Lu TANG Leyue LI Hongwei HE Meixi LI Rongxing Center for spatial information Science and Sustainable Development Applications Tongji UniversityShanghai 200092China College of Surveying and Geo-Informatics Tongji UniversityShanghai 200092China

The Antarctic Ice Sheet harbors more than 90%of the Earth ice mass,with significant losses experienced through dynamic thinning,particularly in West *** crucial aspect of investigating ice mass balance in historical periods preceding 1990 hinges on the utilization of ice velocities derived from optical satellite *** employed declassified satellite images and Landsat images with normalized cross correlation based image matching,adopting an adaptive combination of skills and methods to overcome challenges encountered during the mapping of historical ice velocity in West Antarctica.A basin-wide synthesis velocity map encompassing the coastal regions of most large-scale glaciers and ice shelves in West Antarctica has already been successfully *** results for historical ice velocities cover over 70%of the grounding line in most of the West Antarctic *** adjustments,we uncovered overestimations in ice velocity measurements over an extended period,transforming our ice velocity map into a spatially deterministic,temporally average *** all velocity measurements,Thwaites Glacier exhibited a notable spatial variation in the fastest ice flowline and velocity *** distributions on Thwaites Glacier displayed a clear consistency with the positions of subsequent front calving events,offering insights into the instabilities of ice shelves.

关键词： Antarctica ice velocity overestimation correction historical imagery

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Refined acoustic holography via nonlocal metasurfaces

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 113-123页

作者： Shuhuan Xie Hongyu Ma Junmei Cao Fangshuo Mo Qian Cheng Yong Li Tong Hao Institute of Acoustics School of Physics Science and EngineeringTongji UniversityShanghai 200092China Center for spatial information Science and Sustainable Development Applications Tongji UniversityShanghai 200092China College of Surveying and Geo-Informatics Tongji UniversityShanghai 200092China

Holography can provide the desired wavefront phase and/or amplitude for imaging,particle manipulation,bacteria trapping,and cell patterning in optics and ***,previous work on acoustic holography is mostly based on local design optimization,either using active control of the sound source or relying on the structural design to provide the desired *** precise control over the acoustic field remains a significant ***,we realize refined single-plane symmetric binary amplitude,asymmetric intensity gradient amplitude,and bi-objective hologram through the non-local holographic imaging theory that considers the acoustic coupling of structural units in *** taking into account the self-radiation and mutual radiation between many small units on a plate of well-designed thickness,as well as the transmission through the plate's apertures,we can effectively regulate the sound field behind the *** demonstrate the effectiveness of our approach through numerical simulations and experiments,showcasing a circle,a black hole,and a bi-objective with a circle and a square ***,the acoustic black hole hologram precisely reconstructs the intensity gradient distribution at two bright *** non-local holographic imaging theory is valuable for the fine-intensity regulation of the sound field and is expected to be applied in ultrasound diagnosis and treatment,medical imaging,and other fields.

关键词： acoustic holograms non-local interactions fine intensity modulation acoustic metasurfaces

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Modeling urban redevelopment:A novel approach using time-series remote sensing data and machine learning

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Geography and Sustainability 2024年第2期5卷 211-219页

作者： Li Lin Liping Di Chen Zhang Liying Guo Haoteng Zhao Didarul Islam Hui Li Ziao Liu Gavin Middleton Center for spatial information Science and Systems George Mason UniversityFairfaxVA22030USA Department of Geography and Geoinformation Science George Mason UniversityFairfaxVA22030USA

Accurate mapping and timely monitoring of urban redevelopment are pivotal for urban studies and decisionmakers to foster sustainable urban *** mapping methods heavily depend on field surveys and subjective questionnaires,yielding less objective,reliable,and timely *** advancements in Geographic information Systems(GIS)and remote-sensing technologies have improved the identification and mapping of urban redevelopment through quantitative analysis using satellite-based ***,challenges persist,particularly concerning accuracy and significant temporal *** study introduces a novel approach to modeling urban redevelopment,leveraging machine learning algorithms and remote-sensing *** methodology can facilitate the accurate and timely identification of urban redevelopment *** study’s machine learning model can analyze time-series remote-sensing data to identify spatio-temporal and spectral patterns related to urban *** model is thoroughly evaluated,and the results indicate that it can accurately capture the time-series patterns of urban *** research’s findings are useful for evaluating urban demographic and economic changes,informing policymaking and urban planning,and contributing to sustainable urban *** model can also serve as a foundation for future research on early-stage urban redevelopment detection and evaluation of the causes and impacts of urban redevelopment.

关键词： Urban redevelopment Urban sustainability Remote sensing Time-series analysis Machine learning

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High-order Autler–Townes splitting in electrically tunable photonic molecules

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Photonics Research 2024年第8期12卷 1794-1801页

作者： YIHAO CHEN JUNTAO DUAN JIN LI YAN CHEN JIEWEN LI JIANAN DUAN XIAOCHUAN XU JIAWEI WANG School of Integrated Circuit Harbin Institute of Technology(Shenzhen)Shenzhen 518055China College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China National Key Laboratory of Laser spatial information Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Whispering gallery mode optical microresonators represent a promising avenue for realizing optical analogs of coherent light–atom interactions,circumventing experimental ***-optical analogs of Autler–Townes splitting have been widely demonstrated,harnessing coupled optical microresonators,also known as photonic molecules,wherein the strong coupling between resonant fields enables energy level ***,we report the characterizations of Autler–Townes splitting in waveguide-coupled microring dimers featuring mismatched *** exploiting backscattering-induced coupling via Rayleigh and Mie scatterers in individual rings,high-order Autler–Townes splitting has been realized,yielding supermode hybridization in a multi-level *** resonance detuning using an integrated phase shifter,intra-cavity coupling-induced splitting becomes almost indistinguishable at the zero-detuning point where the strong inter-cavity coupling counteracts the imbalance of backscattering strengths in individual *** demonstrations on the maturing silicon photonics platform,our findings establish a framework of electrically tunable photonic molecules for coupling-mediated Autler–Townes splitting,offering promising prospects for on-chip signal generation and processing across classical and quantum regimes.

关键词： tunable tuning waveguide

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Hybrid ITO Algorithm for Large-Scale Colored Traveling Salesman Problem

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Chinese Journal of Electronics 2024年

作者： Xueshi DONG College of Computer Science and Technology Qingdao University Beijing Key Laboratory of Urban spatial information Engineering School of Computer Science Wuhan University

In the fields of intelligent transportation and multi-task cooperation, many practical problems can be modeled by colored traveling salesman problem (CTSP). When solving large-scale CTSP with a scale of more than 1000dimensions, their convergence speed and the quality of their solutions are limited. This paper proposes a new hybrid ITO(HITO) algorithm, which integrates two new strategies, crossover operator and mutation strategy, into the standard ITO. In the iteration process of HITO, the feasible solution of CTSP is represented by the double chromosome coding, and the random drift and wave operators are used to explore and develop new unknown regions. In this process, the drift operator is executed by the improved crossover operator, and the wave operator is performed by the optimized mutation strategy. Experiments show that HITOis superior to the known comparison algorithms in term of the quality solution.

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