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Single Oil Palm Tree Detection and Its Potential Expansion in Honduras

IEEE Transactions on Geoscience and Remote Sensing 2025年 63卷

作者： Zhang, Hang Cui, Yaoping Yu, Le Enrique Corrales Andino, Rafael Zhang, Sen Cui, Kailong Zhao, Tianwei Liang, Han Henan University College of Geographical Sciences Faculty of Geographical Science and Engineering Zhengzhou450046 China Henan University Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions Ministry of Education Kaifeng475004 China Tsinghua University Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System Science Beijing100084 China Tegucigalpa11101 Honduras International Institute for Earth System Sciences Nanjing University Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing210023 China

Honduras is among the ten largest palm oil producers in the world. Accurately detecting the current plantation status and oil palm distribution is crucial to optimize the planting layout. However, current information on single oil palm trees in Honduras is scarce. Here, we used submeter-resolution RGB satellite images in 2022 to detect the spatial distribution and single oil palm tree in Honduras with the four-direction gradient difference (FGD), single-tree feature extraction, and double-ring detection methods. In the accuracy validation zones, the recall, precision, and F1-score metrics for the spatial distribution of oil palm were 86.50%, 86.57%, and 86.53%, respectively;counting accuracy for single oil palm trees was 86.75%;and localization accuracy was approximately 6 m. We estimated 0.25 million hectares (ha) of oil palm plantation area in Honduras, corresponding to 28.27 million trees and an average density of 113 trees/ha. Furthermore, we categorized planted land into highly or moderately suitable zones for future expansion. Among the 0.25 million ha of potentially available land, the highly and moderately suitable zones represented 10 501 and 242 120 ha, respectively, with the potential to carry approximately 28.55 million oil palms. For future oil palm expansion, priority should be given to highly suitable zones. This study not only characterized the distribution and single oil palm properties in Honduras but also suggested potentially suitable zones for future plantation expansion, thereby providing important methodological references and data support to assess the impact of oil palm planting on the ecological environment and socioeconomic aspects at the country scale. © 1980-2012 IEEE.

关键词： Satellite imagery

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Symplectic Wigner Distribution in the Linear Canonical Transform Domain: Theory and application

arXiv

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arXiv 2025年

作者： He, Yangfan Zhang, Zhichao School of Communication and Artificial Intelligence School of Integrated Circuits Nanjing Institute of Technology Nanjing211167 China School of Mathematics and Statistics Nanjing University of Information Science and Technology Nanjing210044 China Key Laboratory of System Control and Information Processing Ministry of Education Shanghai Jiao Tong University Shanghai200240 China Key Laboratory of Computational Science Application of Hainan Province Hainan Normal University Haikou571158 China Key Laboratory of Numerical Simulation of Sichuan Provincial Universities School of Mathematics and Information Sciences Neijiang Normal University Neijiang641000 China

This paper devotes to combine the chirp basis function transformation and symplectic coordinates transformation to yield a novel Wigner distribution (WD) associated with the linear canonical transform (LCT), named as the symplectic WD in the LCT domain (SWDL). It incorporates the merits of the symplectic WD (SWD) and the WD in the LCT domain (WDL), achieving stronger capability in the linear frequency-modulated (LFM) signal frequency rate feature extraction while maintaining the same level of computational complexity. Some essential properties of the SWDL are derived, including marginal distributions, energy conservations, unique reconstruction, Moyal formula, complex conjugate symmetry, time reversal symmetry, scaling property, time translation property, frequency modulation property, and time translation and frequency modulation property. Heisenberg’s uncertainty principles of the SWDL are formulated, giving rise to three kinds of lower bounds attainable respectively by Gaussian enveloped complex exponential signal, Gaussian signal and Gaussian enveloped chirp signal. The optimal symplectic matrices corresponding to the highest time-frequency resolution are generated by solving the lower bound optimization (minimization) problem. The time-frequency resolution of the SWDL is compared with those of the SWD and WDL to demonstrate its superiority in LFM signals time-frequency energy concentration. A synthesis example is also carried out to verify the feasibility and reliability of the theoretical analysis. Copyright © 2025, The Authors. All rights reserved.

关键词： Wigner-Ville distribution

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A New Approach to Airborne High Resolution SAR Motion Compensation for Large Trajectory Deviations

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电子学报(英文版) 2012年第4期21卷 764-769页

作者： MENG Dadi HU Donghui DING Chibiao Key Laboratory of Technology in Geospatial Information Processing and Application System Chinese Academy of Sciences Beijing 100190 China Institute of Electronics Chinese Academy of Sciences Beijing 100190 China

The Two-step algorithm (TSA) is widely used for trajectory deviation compensation of airborne Synthetic aperture radar (SAR), by which most of the mo- tion errors are compensated before Range curve migration compensation (RCMC) and the residual after the RCMC. We found that the RCMC in the presence of the residual motion errors results in additional range shift errors hard to be compensated for. Based on theoretical investiga- tions, this shortage of TSA is reported and a new compen- sation scheme which greatly alleviates the RCMC induced errors is proposed. Besides, range resampling considering the residual motion errors is very convinent, which, how- ever, is boresome in TSA. The new method is effective to compensate the high resolution SAR systems for large tra- jectory deviations, which is hard to be achieved by TSA because of the uncompensated errors. Results on the sim- ulated data are provided to demonstrate the effectiveness of the new method.

关键词：机载合成孔径雷达高分辨率SAR 运动补偿弹道偏差运动误差 TSA 偏差补偿误差范围 Synthetic aperture radar （SAR）, Motion compensation, Space variant.

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Sampled-data Observer Design for a Class of Stochastic Nonlinear systems Based on the Approximate Discrete-time Models

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IEEE/CAA Journal of Automatica Sinica 2017年第3期4卷 507-511页

作者： Xinxin Fu Yu Kang Pengfei Li Department of Automation University of Science and Technology of China State Key Laboratory of Fire Science Department of AutomationInstitute of Advanced TechnologyUniversity of Science and Technology of China Key Laboratory of Technology in GeoSpatial Information Processing and Application System Chinese Academy of Sciences IEEE

In this paper,we studied the approximate sampleddata observer design for a class of stochastic nonlinear ***-Maruyama approximation was investigated in this paper because it is the basis of other higher precision numerical methods,and it preserves important structures of the nonlinear ***,the form of Euler-Maruyama model is simple and easy to be *** results provide a reference for sampled-data observer design method for such stochastic nonlinear systems,and may be useful to many practical control applications,such as tracking control in mechanical *** the effectiveness of the approach is demonstrated by a simulation example.

关键词： Approximation model exponentially bounded sampled-data observer stochastic nonlinear

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Bell State Preparation Based on Switching Between Quantum system Models

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Journal of systems Science & Complexity 2017年第2期30卷 347-356页

作者： ZHOU Juan KUANG Sen CONG Shuang Department of Automation University of Science and Technology of ChinaHefei 230027China CAS Key Laboratory of Technology in Geo-spatial Information Processing and Application System University of Science

For the preparation of any target Bell state under continuous quantum measurement, this paper proposes a method which achieves the control objective by switching between two different models or by switching between two control channels under one model. Proper control Hamiltonians are selected for the two system models, a switching strategy between the two models is designed, and the stability of the whole switching system is proved in theory. For a given target Bell state, the effectiveness of the proposed switching control strategy between different models is illustrated through simulation experiments.

关键词： Bell state model switching quantum systems switching strategy.

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Examining the Fourier Spectrum of Speech Signal from a Time-Frequency Perspective for Automatic Depression Level Prediction

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IEEE Transactions on Affective Computing 2025年

作者： Niu, Mingyue Tao, Jianhua He, Yongjun Zhang, Shiqing Li, Ming YanShan University School of Information Science and Engineering Qinhuangdao066004 China Key Laboratory for Computer Virtual Technology and System Integration of Hebei Province China Tsinghua University Department of Automation Bejing100190 China University of Chinese Academy of Sciences School of Artificial Intelligence Beijing100049 China Harbin Institute of Technology School of Computer Science and Technology Harbin150001 China Taizhou University Institute of Intelligent Information Processing Taizhou318000 China Zhejiang Normal University Zhejiang Key Laboratory of Intelligent Education Technology and Application Jinhua321004 China Zhejiang Institute of Optoelectronics Jinhua321004 China

Currently, many studies use Fourier amplitude spectra of speech signals to predict depression levels. However, those works often treat Fourier amplitude spectra as images or sequences to capture depression cues using convolutional neural networks or multilayer perceptrons. Therefore, they ignore the complex element composition and time-frequency attributes of Fourier spectra, which is not conducive to capturing the differences among individuals with different depression levels. For this reason, we construct a Time-Frequency Self-Embedding (TFSE) module, which not only stores the correlation relationship among real (imaginary) parts of Fourier spectra of different subjects from the time-frequency perspective, but also maintain the physical properties of data through the weight embedding process. Besides, Global Average Pooling (GAP) or linear layers are difficult to balance both temporal and frequency dimensions in the vectorization process. Therefore, we construct a Time-Frequency Tensor Vectorization (TFTV) module, which summarizes each channel along time and frequency dimensions, and then generates the vectorization result by integrating various channels. In this way, we combine TFSE and TFTV modules to form our SpectrumFormer model for predicting depression levels. Evaluation indicators on AVEC 2013 and AVEC 2014 depression databases imply the progressiveness of our model. © 2010-2012 IEEE.

关键词： Depression level prediction Real and imaginary parts Tensor vectorization Time-frequency attributes

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Geostationary autonomous trajectory determination technology based on enhanced inter-satellite links of the Beidou medium earth orbit constellation

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Aerospace Science and technology 2025年 163卷

作者： Jiao, Fangtan Hu, Yuxin Yu, Xiaodong Wang, Haihong Chen, Qiuli Aerospace Information Research Institute Chinese Academy of Sciences Beijing 100094 China Key Laboratory of Geo-spatial Information Processing and Application System Technology Chinese Academy of Sciences Beijing100190 China University of Chinese Academy of Sciences Beijing100049 China School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences Beijing100049 China Institute of Telecommunication and Navigation Satellite CAST Beijing100094 China

Trajectory determination is critical for autonomous operations in Geostationary Orbit (GEO). However, the existing methods cannot satisfy the need for stability and accuracy in short-cycle scenarios. Since the emerging method based on the Ka-band Inter-Satellite Link (ISL) of the Beidou satellite navigation system medium Earth orbit constellation has the advantages of high accuracy and anti-interference, this paper applies it to the autonomous operations of GEO satellites and analyzes the feasibility and link characteristics. Different from previous ISL-related studies about long-term orbit determination, there is an issue of periodic failure of priori orbital data caused by frequent maneuvers in short-cycle autonomous operations for ISL-based applications. In this paper, by fusing the priori clock bias information and multiple ISL observation data under the constraint of a sub-hour period, we propose an ISL-based fractional steps filtering method containing rapid contraction and precise tracking, assisted by an optimized satellite selection strategy, to address the issue above. The result indicates that thanks to an average number of 12.16 visible navigation satellites for GEO users, the proposed method with dispersed and diversified satellite selection scheme gives excellent results, with convergence to sub-meter accuracy in 10 min on average that satisfies the constraint of a sub-hour period and shows a 41.1 % improvement in average convergence time efficiency compared to the traditional method. Moreover, regarding trajectory determination accuracy in short-cycle autonomous operations, the root-mean-square error achieves about 0.38 m, which is better than the result of existing applications of about 10–20 m precision, demonstrating the advantages of the proposed method. © 2025 Elsevier Masson SAS

关键词： Geostationary satellites

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Dynamic data packing towards the optimization of QoC and QoS in networked control systems

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Science China(Technological Sciences) 2016年第1期59卷 72-80页

作者： KANG Yu ZHAO YunBo Department of Automation and State Key Laboratory of Fire Science University of Science and Technology of China Key Laboratory of Technology in Geo-Spatial Information Processing and Application System Chinese Academy of Sciences Department of Automation Zhejiang University of Technology

A class of networked control systems is investigated whose communication network is shared with other applications. The design objective for such a system setting is not only the optimization of the control performance but also the efficient utilization of the communication resources. We observe that at a large time scale the data packet delay in the communication network is roughly varying piecewise constant, which is typically true for data networks like the Internet. Based on this observation, a dynamic data packing scheme is proposed within the recently developed packet-based control framework for networked control systems. As expected this proposed approach achieves a fine balance between the control performance and the communication utilization: the similar control performance can be obtained at dramatically reduced cost of the communication resources. Simulations illustrate the effectiveness of the proposed approach.

关键词： networked control systems packet delay variation dynamic data packing quality of control quality of service

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An extended processing scheme for coherent integration and parameter estimation based on matched filtering in passive radar

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第11期15卷 1071-1085页

作者： Xin GUAN Li-hua ZHONG Dong-hui HU Chi-biao DING Key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences University of Chinese Academy of Sciences

In passive radars, coherent integration is an essential method to achieve processing gain for target detection. The cross ambiguity function(CAF) and the method based on matched filtering are the most common approaches. The method based on matched filtering is an approximation to CAF and the procedure is:(1) divide the signal into snapshots;(2) perform matched filtering on each snapshot;(3) perform fast Fourier transform(FFT) across the snapshots. The matched filtering method is computationally affordable and can offer savings of an order of 1000 times in execution speed over that of CAF. However, matched filtering suffers from severe energy loss for high speed targets. In this paper we concentrate mainly on the matched filtering method and we use keystone transform to rectify range migration. Several factors affecting the performance of coherent integration are discussed based on the matched filtering method and keystone transform. Modified methods are introduced to improve the performance by analyzing the impacts of mismatching, precision of the keystone transform, and discretization. The modified discrete chirp Fourier transform(MDCFT) is adopted to rectify the Doppler expansion in a multi-target scenario. A novel velocity estimation method is proposed, and an extended processing scheme presented. Simulations show that the proposed algorithms improve the performance of matched filtering for high speed targets.

关键词： keystone transform Matched filtering MDCFT Mismatching Passive radar Velocity estimation

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Self-Tuning Asynchronous Filter for Linear Gaussian system and applications

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IEEE/CAA Journal of Automatica Sinica 2018年第6期5卷 1054-1061页

作者： Wenjun Lv Yu Kang Yunbo Zhao Department of Automation University of Science and Technology of ChinaHefei 230027China State Key Laboratory of Fire Science Department of Automation and Institute of Advanced TechnologyUniversity of Science and Technology of ChinaHefei 230027China Key Laboratory of Technology in GeoSpatial Information Processing and Application System Chinese Academy of SciencesBeijing 100190China College of Information Engineering Zhejiang University of TechnologyHangzhou 310023China

In this paper, optimal filtering problem for a class of linear Gaussian systems is studied. The system states are updated at a fast uniform sampling rate and the measurements are sampled at a slow uniform sampling rate. The updating rate of system states is several times the sampling rate of measurements and the multiple is constant. To solve the problem,we will propose a self-tuning asynchronous filter whose contributions are twofold. First, the optimal filter at the sampling times when the measurements are available is derived in the linear minimum variance sense. Furthermore, considering the variation of noise statistics, a regulator is introduced to adjust the filtering coefficients adaptively. The case studies of wheeled robot navigation system and air quality evaluation system will show the effectiveness and practicability in engineering.

关键词： Air quality evaluation system linear Gaussian system wheeled robot navigation system

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