- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 Global Smart Industry Conference (GloSIC) - Chelyabinsk, Russia (2018.11.13-2018.11.15)] 2018 Global Smart Industry Conference (GloSIC) - Diagnostics of External Defects of Railway Infrastructure by Analysis of its Images
摘要： An important component of the safe movement of the railway transport is the absence of visible rail defects. The external defects of the track infrastructure were analyzed according to the criteria of detection accuracy and the conditions of applicability of the methods of their detection. For the diagnostics of the railway track, a passive defectoscopy method, based on stereo vision and blur analysis, is proposed. This system can be implemented in a hardware-software control system and is located on ground transport-technological devices.
关键词： railway track,kinematic characteristics,stereo vision,image blur,distance estimation,control system,depth of field,video monitoring
更新于2025-09-04 15:30:14
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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 - The Potential of Sentinel Satellites for Large Area Aboveground Forest Biomass Mapping
摘要： Estimation of aboveground forest biomass is critical for regional carbon policies and sustainable forest management. Both passive optical remote sensing and active microwave remote sensing can play an important role in the monitoring of forest biomass. In this study, the recently launched Sentinel-2 Multi Spectral Instrument satellite and Sentinel-1 SAR satellite systems were evaluated and integrated to investigate the relative strengths of each sensor for mapping aboveground forest biomass at a regional scale. The Australian state of Victoria, with its wide range of forest vegetation was chosen as the study area to demonstrate the scalability and transferability of the approach. In this study aboveground forest biomass (AGB) was defined as the tons of carbon per hectare for the aboveground components (stem, branches, leaves) of all live large trees greater than 10 cm in diameter at breast height (DBHOB). Sentinel-2 and Sentinel-1 data were fused within a machine learning framework using a boosted regression tree model and high-quality ground survey data. Multi-criteria evaluations showed the use of the two independent and fundamentally different Sentinel satellite systems were able to provide robust estimates (R2 of 0.62, RMSE of 32.2 t.C.ha-1) of aboveground forest biomass, with each sensor compensating for the weakness (cloud perturbations and spectral saturation for Sentinel 2, and sensitivity to ground moisture for Sentinel 1) of each other. As archives for Sentinel-2 and Sentinel-1 continue to grow, mapping aboveground forest biomass and dynamics at moderate resolution over large regions should become increasingly feasible.
关键词： Sentinel-2,machine learning,data fusion,Sentinel-1,Victoria,boosted regression tree model,Australia,biomass estimation
更新于2025-09-04 15:30:14
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Input-to-Output Instantaneous Polarization Characterization
摘要： This paper proposes a method to represent and predict received signal instantaneous polarization states as a function of arbitrary transmit polarization states for time-dispersive channels. The model incorporates frequency-dependent characterizations to represent the polarization dispersion behavior of a received signal across its bandwidth in a multipath channel. The representation takes advantage of signal dispersion features typical of depolarized signals, and employs subbanded characterizations to achieve polarization representations exhibiting high degrees of polarization in each subband. Experiments are conducted that demonstrate the utility of the modeling approach to predict polarization dispersion responses for arbitrary transmit polarizations based on measurements from two orthogonal transmit polarizations.
关键词： radiowave propagation,Stokes parameters,polarization estimation,dispersion
更新于2025-09-04 15:30:14
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[IEEE 2018 Ubiquitous Positioning, Indoor Navigation and Location-Based Services (UPINLBS) - Wuhan, China (2018.3.22-2018.3.23)] 2018 Ubiquitous Positioning, Indoor Navigation and Location-Based Services (UPINLBS) - Monocular Visual-Inertial State Estimation With Online Temporal Calibration
摘要： In most of visual-inertial state estimation frameworks, camera is usually assumed synchronized with inertial measurement unit (IMU). However, in practice, the timestamps of camera and IMU are typically affected by a time-varying delay, especially for low-cost IMU-camera integrated system (e.g. android phone). Tracking failures could occur easily then. In this paper, we discuss the effect of the temporal offset on map points triangulation and nonlinear optimization during visual-inertial simultaneous localization and mapping (SLAM) process, and propose two feasible solutions for compensating the offset between camera and IMU. We choose the simpler solution and propose a computationally tractable approach which can estimate the offset with all other variables of interest (the IMU pose, the camera-IMU calibration, etc.). Our simulation results demonstrate that the proposed approach is effective in scenarios involving both constant and time-varying offsets.
关键词： visual-inertial state estimation,camera,temporal calibration,SLAM,IMU
更新于2025-09-04 15:30:14
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Multi-resolution Image Fusion in Remote Sensing () || Image Fusion: Model Based Approach with Degradation Estimation
摘要： Recently, many researchers have attempted to solve the problem of multi-resolution image fusion by using model based approaches, with emphasis on improving the fused image quality and reducing color distortion [273, 121]. They model the low resolution (LR) MS image as a blurred and noisy version of its ideal high resolution (HR) fused image. Solving the problem of fusion by the model based approach is desirable since the aliasing present due to undersampling of the MS image can be taken care of while modelling. Fusion using the interpolation of MS images and edge-preserving ?lters as given in Chapter 3 do not consider the effect of aliasing which is due to undersampling of MS images. The aliasing in the acquired image causes distortion and, hence, there exists degradation in the LR MS image. In this chapter, we propose a model based approach in which a learning based method is used to obtain the required degradation matrix that accounts for aliasing. Using the proposed model, the ?nal solution is obtained by considering the model as an inverse problem. The proposed approach uses sub-sampled as well as non sub-sampled contourlet transform based learning and a Markov random ?eld (MRF) prior for regularizing the solution.
关键词： model based approach,multi-resolution image fusion,degradation estimation,contourlet transform,Markov random field
更新于2025-09-04 15:30:14
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Multi-resolution Image Fusion in Remote Sensing () || Image Fusion: Application to Super-resolution of Natural Images
摘要： Increasing the spatial resolution of a given test image is of interest to the image processing community since the enhanced resolution of the image has better details when compared to the corresponding low resolution image. Super-resolution (SR) is an algorithmic approach in which a high spatial resolution image is obtained by using single/multiple low resolution observations or by using a database of LR–HR pairs. The linear image formation model discussed for image fusion in Chapter 4 is extended here to obtain an SR image for a given LR test observation. In the image fusion problem, the available Pan image was used in obtaining a high resolution fused image. Similar to the fusion problem, SR is also concerned with the enhancement of spatial resolution. However, we do not have a high resolution image such as a Pan image as an additional observation. Hence, we make use of a database of LR–HR pairs in order to obtain the SR for the given LR observation. Here, we use contourlet based learning to obtain the initial SR estimate which is then used in obtaining the degradation as well as the MRF parameter. Similar to the fusion problem discussed in Chapter 4, an MAP–MRF framework is used to obtain the final SR image.
关键词： image processing,degradation estimation,MAP–MRF framework,Super-resolution,contourlet transform
更新于2025-09-04 15:30:14
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[IEEE 2018 International Power Electronics Conference (IPEC-Niigata 2018-ECCE Asia) - Niigata (2018.5.20-2018.5.24)] 2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia) - The Lifetime Assessment of a Micro-Inverter for PV Applications
摘要： Recently, introducing grid-tied PV systems is recommended in many countries. The inverter lifetime in PV applications is affected by their operating conditions. That is affected by the thermal loading of the power devices lifetime of electrolytic capacitors. Especially, the electrolytic capacitors at the DC-link to compensate the power ripple decreases when the ambient temperature increases. To improve the lifetime, a micro-inverter with an active buffer at the DC-link is introduced in this paper. In this micro-inverter, the DC-link electrolytic capacitor is replaced with a ceramic capacitor that has small capacitance. However, the reliability performance of the entire micro-inverter has not been evaluated. This paper thus assesses the lifetime of the micro-inverter considering the operational conditions (i.e., ambient temperature and solar irradiance, also referred to as mission profiles). A comparison between the proposed circuit with an active buffer and the conventional circuit based on a boost chopper is performed in this paper. It is revealed that the lifetime of the micro-inverter is very long. This is due to the over-designed power devices.
关键词： Photovoltaic,Lifetime estimation,Micro inverter
更新于2025-09-04 15:30:14