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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Development of Fusion Approach for Estimation of Vegetation Fraction Cover with Drone and Sentinel-2 Data
摘要： Fractional vegetation cover (FVC) is usually referred to as an important parameter for vegetation health monitoring and also used as control parameter in terrestrial ecosystem change detection. In recent year several models have been developed for FVC measurement using satellite data and digital images at regional and global scale. For the validation and modification in these models need to a precise ground truth information. FVC measured using digital camera act as an efficient ground truth information, but it is also lack in accuracy due to limited number of images and sampling points are possible to take with camera. Drone is the recent trend for precision agriculture monitoring and can be used as substitute to overcome these problems. In this paper an efficient method of ground truth FVC measurement using drone image is developed, which is further used for development of a sigmoid model to measure FVC using Sentinel-2 data for larger area. Results of the obtained model are compared with ground truth FVC and obtained value of RMSE is 0.10. FVC are also measured with dimidiate pixel model and obtained RMSE value with ground truth FVC is 0.17. Results show that developed model can be used for efficient measurement of fractional vegetation cover.
关键词： vegetation index,drone,NDVI,Dimidiate pixel model,FVC,Sentinel-2
更新于2025-09-10 09:29:36
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readout chip
摘要： In order to solve the leakage current saturation of Topmetal-???? ? and to maintain its low noise, Topmetal-?????? has been designed. The new chip has the same Rolling-Shutter module as Topmetal-???? ?. It contains a charge-collection electrode and a metal layer surrounding it, called guard ring. This new design contains three different sections. Section A has the same structure as Topmetal-???? ?, in that the electrode is exposed and guard ring is covered by insulating layer. Section B has both electrode and guard ring exposed. Section C has guard ring exposed but electrode covered by insulating layer. Preliminary experiments show that if coupled with CdZnTe detector, Section C of the Topmetal-?????? chip is capable of solving the leakage current saturation. Meanwhile, the electrode receives induced signal. Moreover, the charge induction efficiency is influenced by several parameters, such as thickness of adhesive epoxy resin, collecting electrode size, etc. Thus, the optimization of parameters for induction efficiency is studied by simulations. According to the simulation results, it can be concluded that thinner epoxy resin thickness and bigger anode size contribute to higher induction efficiency.
关键词： Leakage current,CdZnTe,Induced signal simulation,Topmetal,Low noise readout chip,Pixel
更新于2025-09-10 09:29:36
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Fully Depleted SOI Pixel Detector With Multijunction Structure in p-Type Substrate
摘要： A fully depleted silicon-on-insulator (SOI) pixel detector with multijunction structure in p-type substrate is proposed to reduce the diode capacitance and improve the effective shielding between the SOI circuits and sensor. A buried p-well (BPW) and a buried n-well (BNW) are applied to their respective bias voltages to shield SOI circuits from the sensor in the substrate. BPW is biased to counteract the back-gate effect. A deeply BPW is employed to form a potential barrier to electrons in BNW, stopping the front-to-back leakage current. Lateral electric field is also formed to accelerate holes to the p+ charge collector. The simulation results demonstrate that the pixel can achieve its objectives under a full depletion condition. The capacitance of the charge collector can be reduced, which depends primarily on the charge-collector/BNW junction.
关键词： fully depleted,Capacitance,silicon-on-insulator (SOI) pixel detector,crosstalk
更新于2025-09-10 09:29:36
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Simplified, automated methods for assessing pixel intensities of fluorescently-tagged drugs in cells
摘要： Assessing the cytoplasmic uptake of fluorescently-tagged drugs in heterogeneous cell types currently involves time-consuming manual segmentation of confocal microscopy images. We developed a set of methods that incorporate map algebra techniques to facilitate and expedite image segmentation, particularly of the parenchyma of intermediate cells in the stria vascularis of the inner ear. Map algebra is used to apply a convolution kernel to pixel neighborhoods to create a masking image to select pixels in the original image for further operations. Here, we describe the utility of integrated intensity-based, percentile-based, and local autocorrelation-based methods to automate segmentation of images into putative morphological regions for pixel intensity analysis. Integrated intensity-based methods are variants of watershed segmentation tools that determine morphological boundaries from rates of change in integrated pixel intensity. Percentile- and local autocorrelation-based methods evolved out of the process of developing map algebra- and integrated intensity-based tools. We identified several simplifications that are surprisingly effective for image segmentation and pixel intensity analysis. These methods were empirically validated on three levels: first, the algorithms were developed based on iterations of inspected results; second, algorithms were tested for various types of robustness; and third, developed algorithms were validated against results from manually-segmented images. We conclude the key to automated segmentation is supervision of output data.
关键词： pixel intensity analysis,map algebra,fluorescently-tagged drugs,confocal microscopy,automated segmentation
更新于2025-09-10 09:29:36
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A Nondestructive Detection Method for Mixed Veterinary Drugs in Pork Using Line-Scan Raman Chemical Imaging Technology
摘要： This study reports a nondestructive detection method using Raman chemical imaging (RCI) technology for the simultaneous determination of multiple veterinary drugs, such as ofloxacin, chloramphenicol, and sulfadimidine, in pork. A line-scan Raman imaging system was employed to acquire images of pure veterinary drugs and pork samples containing single and mixed drugs. Raman characteristic peaks at 1623, 1353, and 1147 cm?1 were identified for ofloxacin, chloramphenicol, and sulfadimidine, respectively. An image processing method was proposed to calculate the Bpixel-ratio^ values in each feature image, and linear regression models for a single veterinary drug were then established between the Bpixel-ratio^ values and the actual concentrations. By applying the models to samples with mixed veterinary drugs, the concentrations of the three drugs were predicted with correlation coefficients of 0.978, 0.986, and 0.984. The satisfactory results indicated that along with the proposed Bpixel-ratio^ method, RCI technology enables the nondestructive quantitation and spatial distribution visualization of multiple veterinary drug residues.
关键词： Raman chemical imaging,Spatial distribution,Pork,Veterinary drugs,Pixel-ratio,Quantitative analysis
更新于2025-09-10 09:29:36
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Attention-Mechanism-Containing Neural Networks for High-Resolution Remote Sensing Image Classification
摘要： A deep neural network is suitable for remote sensing image pixel-wise classi?cation because it effectively extracts features from the raw data. However, remote sensing images with higher spatial resolution exhibit smaller inter-class differences and greater intra-class differences; thus, feature extraction becomes more dif?cult. The attention mechanism, as a method that simulates the manner in which humans comprehend and perceive images, is useful for the quick and accurate acquisition of key features. In this study, we propose a novel neural network that incorporates two kinds of attention mechanisms in its mask and trunk branches; i.e., control gate (soft) and feedback attention mechanisms, respectively, based on the branches’ primary roles. Thus, a deep neural network can be equipped with an attention mechanism to perform pixel-wise classi?cation for very high-resolution remote sensing (VHRRS) images. The control gate attention mechanism in the mask branch is utilized to build pixel-wise masks for feature maps, to assign different priorities to different locations on different channels for feature extraction recalibration, to apply stress to the effective features, and to weaken the in?uence of other pro?tless features. The feedback attention mechanism in the trunk branch allows for the retrieval of high-level semantic features. Hence, additional aids are provided for lower layers to re-weight the focus and to re-update higher-level feature extraction in a target-oriented manner. These two attention mechanisms are fused to form a neural network module. By stacking various modules with different-scale mask branches, the network utilizes different attention-aware features under different local spatial structures. The proposed method is tested on the VHRRS images from the BJ-02, GF-02, Geoeye, and Quickbird satellites, and the in?uence of the network structure and the rationality of the network design are discussed. Compared with other state-of-the-art methods, our proposed method achieves competitive accuracy, thereby proving its effectiveness.
关键词： feedback attention mechanism,very high resolution,internal classi?er,multi-scale,remote sensing,control gate,attention,pixel-wise classi?cation
更新于2025-09-10 09:29:36
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Heavy ion-induced single event effects in active pixel sensor array
摘要： The complementary metal-oxide-semiconductor (CMOS) active pixel sensors (APSs) can easily be susceptible to heavy-ion radiation in space applications. In this paper, pinned photodiode (PPD) active pixel sensor array have been exposed to heavy ion (Xe, Kr) with linear energy transfer (LET) (50.34, 37) and single event effects (SEEs) were studied. Devices were fully functional and integration time was changed during exposure, No single event latch-up (SEL) and single event functional interrupt (SEFI) happened. However single event transient (SET) effect happened, that is, a dark background with pixel clusters. The number of the pixel clusters, Total collected charge and cluster size were analyzed. Finally, SRIM simulations were conducted on a PPD with aim to predict the number of the electron-hole pairs generated by a heavy ion.
关键词： heavy ions,CMOS active pixel sensor (APS),SEE
更新于2025-09-10 09:29:36
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Principles and prospects for single-pixel imaging
摘要： Modern digital cameras employ silicon focal plane array (FPA) image sensors featuring millions of pixels. However, it is possible to make a camera that only needs one pixel. In these cameras a spatial light modulator, placed before or after the object to be imaged, applies a time-varying pattern and synchronized intensity measurements are made with a single-pixel detector. The principle of compressed sensing then allows an image to be generated. As the approach suits a wide a variety of detector technologies, images can be collected at wavelengths outside the reach of FPA technology or at high frame rates or in three dimensions. Promising applications include the visualization of hazardous gas leaks and 3D situation awareness for autonomous vehicles.
关键词： 3D imaging,computational imaging,spatial light modulator,compressed sensing,infrared imaging,single-pixel imaging,terahertz imaging
更新于2025-09-10 09:29:36
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Coulomb explosion imaging of CH <sub/>3</sub> I and CH <sub/>2</sub> ClI photodissociation dynamics
摘要： The photodissociation dynamics of CH3I and CH2ClI at 272 nm were investigated by time-resolved Coulomb explosion imaging, with an intense non-resonant 815 nm probe pulse. Fragment ion momenta over a wide m/z range were recorded simultaneously by coupling a velocity map imaging spectrometer with a pixel imaging mass spectrometry camera. For both molecules, delay-dependent pump-probe features were assigned to ultraviolet-induced carbon-iodine bond cleavage followed by Coulomb explosion. Multi-mass imaging also allowed the sequential cleavage of both carbon-halogen bonds in CH2ClI to be investigated. Furthermore, delay-dependent relative fragment momenta of a pair of ions were directly determined using recoil-frame covariance analysis. These results are complementary to conventional velocity map imaging experiments and demonstrate the application of time-resolved Coulomb explosion imaging to photoinduced real-time molecular motion.
关键词： pixel imaging mass spectrometry,time-resolved,CH3I,velocity map imaging,photodissociation dynamics,Coulomb explosion imaging,CH2ClI
更新于2025-09-10 09:29:36
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Crop classification with WorldView-2 imagery using Support Vector Machine comparing texture analysis approaches and grey relational analysis in Jianan Plain, Taiwan
摘要： Crop production estimation is of crucial concern in Taiwan, and the government has invested much effort including employing manpower and technologies. Artificial intelligence or data mining technology have been successfully applied on land-cover recognition of remote-sensing imagery. Most studies are employing a pixel-based classification approach to generate the thematic map of land covers. Few studies consider the spatial correlation of adjacent pixels of the same category. Mixed pixel issues usually degrade the prediction accuracy according to previous studies. It is thus the main goal of the present study to explore the spatial effect of adjacent pixels on land-cover mapping. The study region is a WorldView-2 satellite image in Jianan Plain, Taiwan, taken in 2014. Support Vector Machine is used as the underlying classifier. In addition to the eight spectral band intensities, normalized difference vegetation index and grey-level co-occurrence matrix (GLCM) textures are included as ancillary attributes. Furthermore, grey relational analysis (GRA) is employed to assist in classifying croplands. The findings of this study can be summarized as follows: (1) GLCM texture information improves classification accuracy marginally and renders slightly better thematic map, (2) GRA is used to acquire the most important factors concerning discriminating land covers, (3) grey relational grade threshold, a metric designed through GRA, can be used to locate uncertain region of a specified crop, which is possibly caused by mixed pixels.
关键词： GLCM,land cover mapping,support vector machine,Mixed pixel
更新于2025-09-09 09:28:46