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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - A Simulation Based Approach to Estimating the Three Dimensional Structure of the Harvard Forest with Multi-Modal Remote Sensing
摘要： Tracking carbon as it enters and exits each stage of the carbon cycle is necessary to help build understanding of the cycle's mechanics and its effect on climate. Satellite and airplane-based remote sensing technologies have shown promising results in aiding in human understanding of our planet, including vegetative areas. The Harvard Forest has been studied in various ways over the course of the last century. In particular, synthetic aperture radar, LiDAR, and passive optical sensors have each been used to study the Harvard Forest. Employing a form of data fusion, we present an approach to estimate a forest stand's mean canopy height and biomass for each component tree species while employing minimal ground measurements. We present an approach where a database of simulated forest stands is generated containing both homogeneous stands and heterogeneous stands with up to four tree species present in a given stand. Each simulated stand is compared to an input stand on a number of criteria and a figure of similarity is calculated. In the case that a simulated stand isn't found with a figure of similarity below a set threshold, an iterative process is employed to modify the most similar stand to improve the factor of similarity by modifying the stand's species composition, tree densities, heights, and biomasses. A simulated stand, either pre-existing or developed dynamically will be considered a reasonable representation of the physical forest stand and the 3-D structure of the simulated stand will be reported as an estimate for that of the physical forest stand. This method relies heavily on our sensor simulators, including our fractal-based tree geometry generator, as well as SAR, IfSAR, LiDAR, and Optical simulators. We have previously investigated the ability of our method to differentiate between coniferous and deciduous trees in the same forest stand. We propose to extend this to a maximum of four different tree species, and to validate our approach in the Harvard Forest, a heavily studied region in central Massachusetts.
关键词： Harvard Forest,Forest Parameter Estimation,IfSAR,Heterogeneous Forests,SAR,LiDAR
更新于2025-09-23 15:23:52
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Successful optimization of reconstruction parameters in structured illumination microscopy – A practical guide
摘要： The impact of the different reconstruction parameters in super-resolution structured illumination microscopy (SIM) on image artifacts is carefully analyzed. These parameters comprise the Wiener filter parameter, an apodization function, zero-frequency suppression and modifications of the optical transfer function. A detailed investigation of the reconstructed image spectrum is concluded to be suitable for identifying artifacts. For this purpose, two samples, an artificial test slide and a more realistic biological system, were used to characterize the artifact classes and their correlation with the image spectra as well as the reconstruction parameters. In addition, a guideline for efficient parameter optimization is suggested and the implementation of the parameters in selected up-to-date processing packages (proprietary and open-source) is depicted.
关键词： Super resolution,Fluorescence microscopy,Structured illumination microscopy,Parameter estimation,Image reconstruction
更新于2025-09-23 15:23:52
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Deformation Estimation for Time Series InSAR Using Simulated Annealing Algorithm
摘要： Time series interferometric synthetic aperture radar SAR (TSInSAR) is one of the most important surface deformation monitoring techniques, and has been widely used in geodesy. Deformation estimation is one of the main steps of TSInSAR processing, so an effective and efficient algorithm is necessary. Present algorithms have some limitations such as computing costs or errors caused by local extremums. In this work, a novel deformation estimation method based on the simulated annealing (SA) algorithm is proposed to handle this problem. The SA algorithm uses a random search to avoid local extremums and thus can be more likely to get the global optimal solution of deformation. By adopting a better annealing method, this algorithm gets high precision deformation results in less time than most present algorithms. In addition, it can estimate complex nonlinear deformation without adding any computing costs. The results, tested on the real SAR data, confirm the reliability and effectiveness of the SA-based deformation estimation algorithm.
关键词： InSAR,deformation parameter estimation,simulated annealing,TSInSAR
更新于2025-09-23 15:22:29
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[IEEE 2018 OCEANS - MTS/IEEE Kobe Techno-Ocean (OTO) - Kobe, Japan (2018.5.28-2018.5.31)] 2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO) - Parameter Estimation for Rayleigh-Pearson Mixture Model Based on Expectation-Maximization Algorithm
摘要： In this paper I propose a mixture distribution model with Rayleigh and Pearson distributions in order to represent the statistics of the reverberation. In addition the paper studies a parameter estimation method for the mixture distribution. As a preliminary step the parameter estimation of Pearson distribution is studied. Then the method of the parameter estimation is derived in the Rayleigh-Pearson mixture model based on the expectation-maximization (EM) technique. Simulation results have demonstrated that the parameter estimation method provides adequate performance.
关键词： Pearson distribution,parameter estimation,EM algorithm,mixture distribution
更新于2025-09-23 15:22:29
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An Improved DBSCAN Method for LiDAR Data Segmentation with Automatic Eps Estimation
摘要： Point cloud data segmentation, ?ltering, classi?cation, and feature extraction are the main focus of point cloud data processing. DBSCAN (density-based spatial clustering of applications with noise) is capable of detecting arbitrary shapes of clusters in spaces of any dimension, and this method is very suitable for LiDAR (Light Detection and Ranging) data segmentation. The DBSCAN method needs at least two parameters: The minimum number of points minPts, and the searching radius ε. However, the parameter ε is often harder to determine, which hinders the application of the DBSCAN method in point cloud segmentation. Therefore, a segmentation algorithm based on DBSCAN is proposed with a novel automatic parameter ε estimation method—Estimation Method based on the average of k nearest neighbors’ maximum distance—with which parameter ε can be calculated on the intrinsic properties of the point cloud data. The method is based on the ?tting curve of k and the mean maximum distance. The method was evaluated on different types of point cloud data: Airborne, and mobile point cloud data with and without color information. The results show that the accuracy values using ε estimated by the proposed method are 75%, 74%, and 71%, which are higher than those using parameters that are smaller or greater than the estimated one. The results demonstrate that the proposed algorithm can segment different types of LiDAR point clouds with higher accuracy in a robust manner. The algorithm can be applied to airborne and mobile LiDAR point cloud data processing systems, which can reduce manual work and improve the automation of data processing.
关键词： parameter estimation,segmentation,DBSCAN,LiDAR
更新于2025-09-23 15:22:29
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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - High-Squint SAR Imaging for Noncooperative Moving Ship Target Based on High Velocity Motion Platform
摘要： For high velocity motion platform, it usually takes a shorter azimuth accumulation time to achieve high-squint synthetic aperture radar (SAR) imaging for noncooperative moving ship target with meter-level resolutions. In this case, three-dimensional relative motion of the ship target can be neglected approximately, mainly the translational motion should be considered. However, the magnitude and direction of the target's translational velocity are unknown. To solve the above problem, a two-step imaging method is proposed in this paper. Firstly, the entire scene is coarsely imaged by using the parameters provided by inertial navigation system. The position of the ship target can be judged by two-dimensional order statistics constant false alarm rate (OS-CFAR) detection and ship target pixel clustering. By constructing the band-pass filter in azimuth frequency domain, the data of the target can be obtained effectively, and to a certain extent, sea clutter and noise are suppressed. Then the motion parameters are estimated. Finally, the target is secondarily imaged with the estimated parameters to achieve precise focus. The results of simulation verify the correctness of the analysis and the validity of the proposed method.
关键词： noncooperative moving ship target,motion parameter estimation,high-squint SAR,two-step imaging method
更新于2025-09-23 15:22:29
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A Parameter Estimation based MPPT Method for a PV System using Lyapunov Control Scheme
摘要： There are two types of external variations which change the operating point of a photovoltaic (PV) system: one is environmental change caused by variation in temperature and/or irradiance and the other is load change. The variation in environmental condition changes the PV array characteristic itself whereas the load variation changes the operating point within the same curve. Each type of change can be uniquely identified using history of PV voltage and current measurements. Using the above fact, this paper proposes a fast maximum power point tracking (MPPT) technique for PV array coupled with boost converter. The proposed method determines MPP in a single step by finding out temperature and irradiance at which the PV array is operating. Furthermore, based on the measured values of PV voltage and current, inductor current and load voltage are also calculated, eliminating the need for additional sensors. Lyapunov based controller (LBC) is implemented to track inductor current to its desired value and find the desired duty cycle to reach MPP. The proposed method is validated by both simulation and experimental results under varying temperature, irradiance and load condition. A comparison with the existing MPPT method is also presented in order to show the efficacy of the proposed method.
关键词： MPPT,DC-DC converters,Lyapunov Function,Incremental Conductance,PV cell,Parameter Estimation
更新于2025-09-23 15:21:21
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Successive DSPE-based coherently distributed sources parameters estimation for unmanned aerial vehicle equipped with antennas array
摘要： In electronic countermeasures and reconnaissance, unmanned aerial vehicle (UAV) has played a more and more significant role. Usually when UAV conducts low altitude reconnaissance, due to the complicated environment, the reflected signals of the same source through different propagation paths will produce multipath signals. In this paper, we construct the received multipath signals of UAV with antennas array as coherently distributed (CD) sources model and propose a successive distributed signal parameter estimation (S-DSPE) algorithm to estimate its nominal direction of arrival (DOA) and angular spread. The proposed algorithm simplifies two-dimensional (2D) spectral peak searching within the conventional DSPE algorithm to one-dimensional spectral peak searching, which remarkably reduces the computational complexity of conventional DSPE algorithm. Furthermore, the parameters estimation performance of the proposed algorithm is close to the conventional DSPE algorithm, and outperforms the estimation of signal parameters via rotational invariance technique (ESPIRT) algorithm and propagator method(PM). The simulations results verify the usefulness of the proposed algorithm.
关键词： Distributed signal parameter estimation (DSPE),Nominal direction of arrival (DOA),Coherently distributed(CD),Unmanned aerial vehicle (UAV)
更新于2025-09-23 15:21:21
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On the root mean square error (RMSE) calculation for parameter estimation of photovoltaic models: A novel exact analytical solution based on Lambert W function
摘要： In the literature, one can find a lot of methods and techniques employed to estimate single diode solar photovoltaic (PV) cell parameters. The efficiency of these methods is usually tested by calculating the Root Mean Square Error (RMSE) between the measured and estimated values of the solar PV cell output current. In this work, first, the values of RMSE calculated using 69 different methods published in many journal papers for the well-known RTC France solar PV cell are presented and discussed. Second, a novel exact analytical solution for RMSE calculation based on the Lambert W function is proposed. The results obtained show that the RMSE values were not calculated correctly in most of the methods presented in the literature since the exact expression of the calculated cell output current was not used. Third, the precision of calculation of the methods used for analytical solving of Lambert W equation is presented and discussed. Fourth, the applicability of the proposed solution methodology in accordance with current-voltage characteristics measured in the laboratory for solar modules of Clean Energy Trainer Setup is checked. Identification of its unknown parameters is presented using three optimization techniques. Further, the proposed solution methodology is proven for Solarex MSX–60 PV module, and the most promising 5-parameter single diode parameters are estimated based on minimization of the precise RMSE values calculated. Finally, this work aimed to develop a good base for proper investigation and implementation of optimization algorithms to solve the parameter estimation problem of 5-parameter single diode PV equivalent circuits.
关键词： Root mean square error,5-parameter single diode model,PV parameter estimation,Optimization,RTC France solar cell,Lambert W function
更新于2025-09-23 15:21:01
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Behavior of Specialty Optical Fibers in Crude Oil Environment
摘要： Models of biochemical reaction networks commonly contain a large number of parameters, while at the same time, there is only a limited amount of (noisy) data available for their estimation. As such, the values of many parameters are not well known as nominal parameter values have to be determined from the open scienti?c literature and a signi?cant number of the values may have been derived in different cell types or organisms than that which is modeled. There clearly is a need to estimate at least some of the parameter values from experimental data; however, the small amount of available data and the large number of parameters commonly found in these types of models require the use of regularization techniques to avoid over?tting. A tutorial of regularization techniques, including parameter set selection, precedes a case study of estimating parameters in a signal transduction network. Cross-validation results rather than ?tting results are presented to further emphasize the need for models that generalize well to new data instead of simply ?tting the current data.
关键词： parameter estimation,Computational systems biology,nonlinear dynamical systems
更新于2025-09-23 15:21:01