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基于寒旱指数(CASI)的中国寒旱农业气候资源分布特征
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作者 王莺 张强 +2 位作者 孙芸 姚玉璧 冯新媛 《地球科学进展》 北大核心 2025年第9期961-973,共13页
寒旱区占我国国土面积一半以上,气候条件限制了该地区的农业发展。为充分挖掘农业气候资源优势,探索因地制宜的农业发展路径,亟须科学认识寒旱农业气候资源分布特征与其内在特质。基于2000—2020年高分辨率气象数据,融合热量限制与水分... 寒旱区占我国国土面积一半以上,气候条件限制了该地区的农业发展。为充分挖掘农业气候资源优势,探索因地制宜的农业发展路径,亟须科学认识寒旱农业气候资源分布特征与其内在特质。基于2000—2020年高分辨率气象数据,融合热量限制与水分胁迫构建了寒旱指数,量化了中国寒旱农业气候区空间格局及主导因子。研究发现,寒旱农业气候区占我国国土面积的16.42%,呈东北—西南带状分布。依据寒旱指数可划分为5个等级,其中青藏高原属极端胁迫区(一级),河西走廊与内蒙古高原为典型的农牧交错区(二、三级),东北平原至陇中一带水热配置最优,是适宜规模化发展的核心潜力区(四、五级)。甘肃和内蒙古的寒旱区面积占比超过40%,过渡地带表现出较高的气候敏感性。空间聚集分析进一步揭示,28.52%的区域为低值聚集区,是核心优势产区;28.24%的区域属高值聚集区,构成农业气候高风险带。因子贡献量分析显示,水分胁迫主导的区域占73%,热量限制主导的区域占27%,且寒贡献率随海拔升高显著增加。构建的寒旱指数体系为寒旱农业气候区划提供了新方法论工具,其区划成果可为优化农业空间布局、促进资源精准配置及发展特色产业提供科学依据。 展开更多
关键词 寒旱农业 气候区划 寒旱指数(casi) 聚集模式 因子贡献量
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Improving Image Quality of the Solar Disk Imager(SDI)of the LyαSolar Telescope(LST)Onboard the ASO-S Mission 被引量:1
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作者 Hui Liu Hui Li +11 位作者 Sizhong Zou Kaifan Ji Zhenyu Jin Jiahui Shan Jingwei Li Guanglu Shi Yu Huang Li Feng Jianchao Xue Qiao Li Dechao Song Ying Li 《Research in Astronomy and Astrophysics》 2025年第2期36-45,共10页
The in-flight calibration and performance of the Solar Disk Imager(SDI),which is a pivotal instrument of the LyαSolar Telescope onboard the Advanced Space-based Solar Observatory mission,suggested a much lower spatia... The in-flight calibration and performance of the Solar Disk Imager(SDI),which is a pivotal instrument of the LyαSolar Telescope onboard the Advanced Space-based Solar Observatory mission,suggested a much lower spatial resolution than expected.In this paper,we developed the SDI point-spread function(PSF)and Image Bivariate Optimization Algorithm(SPIBOA)to improve the quality of SDI images.The bivariate optimization method smartly combines deep learning with optical system modeling.Despite the lack of information about the real image taken by SDI and the optical system function,this algorithm effectively estimates the PSF of the SDI imaging system directly from a large sample of observational data.We use the estimated PSF to conduct deconvolution correction to observed SDI images,and the resulting images show that the spatial resolution after correction has increased by a factor of more than three with respect to the observed ones.Meanwhile,our method also significantly reduces the inherent noise in the observed SDI images.The SPIBOA has now been successfully integrated into the routine SDI data processing,providing important support for the scientific studies based on the data.The development and application of SPIBOA also paves new ways to identify astronomical telescope systems and enhance observational image quality.Some essential factors and precautions in applying the SPIBOA method are also discussed. 展开更多
关键词 techniques:image processing Sun:chromosphere Sun:flares methods:numerical
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Snapshot multispectral imaging through defocusing and a Fourier imager network
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作者 Xilin Yang Michael John Fanous +6 位作者 Hanlong Chen Ryan Lee Paloma Casteleiro Costa Yuhang Li Luzhe Huang Yijie Zhang Aydogan Ozcan 《Advanced Photonics Nexus》 2025年第5期24-35,共12页
Multispectral imaging,which simultaneously captures the spatial and spectral information of a scene,is widely used across diverse fields,including remote sensing,biomedical imaging,and agricultural monitoring.We intro... Multispectral imaging,which simultaneously captures the spatial and spectral information of a scene,is widely used across diverse fields,including remote sensing,biomedical imaging,and agricultural monitoring.We introduce a snapshot multispectral imaging approach employing a standard monochrome image sensor with no additional spectral filters or customized components.Our system leverages the inherent chromatic aberration of wavelength-dependent defocusing as a natural source of physical encoding of multispectral information;this encoded image information is rapidly decoded via a deep learning-based multispectral Fourier imager network(mFIN).We experimentally tested our method with six illumination bands and demonstrated an overall accuracy of 98.25%for predicting the illumination channels at the input and achieved a robust multispectral image reconstruction on various test objects.This deep learning-powered framework achieves high-quality multispectral image reconstruction using snapshot image acquisition with a monochrome image sensor and could be useful for applications in biomedicine,industrial quality control,and agriculture,among others. 展开更多
关键词 computational imaging multispectral imaging deep learning image reconstruction Fourier imager network
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RASI:the Robotic All-Sky narrowband Imager
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作者 Yuxin Xin Baoli Lun +6 位作者 Zejun Hu Yue Zhong Kai Ye Hongying Xu Yufeng Fan Bin Li Dehong Huang 《Astronomical Techniques and Instruments》 2025年第6期348-357,共10页
We report a new standalone Robotic All-Sky narrowband Imager(RASI)for auroral and airglow studies.RASI has new optics and an electromechanical system,low operation and installation costs,easy deployment and fully auto... We report a new standalone Robotic All-Sky narrowband Imager(RASI)for auroral and airglow studies.RASI has new optics and an electromechanical system,low operation and installation costs,easy deployment and fully automatic features.The new optics provide an all-sky field of view with excellent image quality and sensitivity.The new electromechanical system design offers a more compact size and the capability for outdoor independent deployment.We have also developed a fully automatic data acquisition software for RASI,which is based on the perception of solar altitude and the all-sky cloud cover.In conclusion,the RASI demonstrates significant advantages over the traditional all-sky narrowband imager,and it is highly suitable for the intensity measurements of large-scale auroras and airglow distributions. 展开更多
关键词 ROBOTIC All-sky imager AURORAS AIRGLOW Optical imaging
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Skin tone bias in online psoriasis imagery:Insights from an international study
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作者 Aman Sandhu Sanya Ailani +4 位作者 Smitesh Padte Priyal Mehta Neha Deo Salim Surani Rahul Kashyap 《World Journal of Clinical Cases》 2025年第36期6-12,共7页
BACKGROUND Psoriasis is often first recognized by patients through online image searches.However,search engine algorithms influenced by geographic location may still produce results that predominantly feature lighter ... BACKGROUND Psoriasis is often first recognized by patients through online image searches.However,search engine algorithms influenced by geographic location may still produce results that predominantly feature lighter skin tones,regardless of the region’s majority skin type.This underrepresentation may limit recognition and delay care for people of color.AIM To examine whether search algorithms tailor region-specific results in terms of skin color for psoriasis imagery.METHODS This observational study recruited 66 participants from 18 countries who conducted image searches for“psoriasis”across various web browsers.During the meeting,a Google form was posted to record observations,and participants reported the diversity of skin tones in the first three rows of search results using a reference image depicting Fitzpatrick types.RESULTS Results showed a global bias toward lighter skin tones,with 94%of participants identifying light skin predominance in the first row and minimal representation of medium or darker skin tones in subsequent results,verified via χ^(2) analysis.Participants who observed darker or mixed skin tones typically found them further down their results.CONCLUSION There remains a significant gap in global representation of psoriasis imagery.This paper deepens the current understanding of bias in online media and pushes for further exploration of more inclusive dermatologic imagery. 展开更多
关键词 PSORIASIS Internet Skin tone bias Image search Global
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On Translation Strategies for the Grass Imagery in Classical Chinese Poetry:A Cultural Semiotic Perspective
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作者 REN Rui LI Yutong SUN Yujingjing 《Sino-US English Teaching》 2025年第2期42-47,共6页
Grass constitutes a vital poetic imagery in classical Chinese poetry,embodying multifaceted symbolic connotations ranging from the tenacity of life to sentiments of separation and nostalgic longing.The translation of ... Grass constitutes a vital poetic imagery in classical Chinese poetry,embodying multifaceted symbolic connotations ranging from the tenacity of life to sentiments of separation and nostalgic longing.The translation of this botanical motif necessitates not merely lexical equivalence,but more importantly,the transmission of its profound cultural resonance and aesthetic essence.This study posits that effective rendition of grass imagery should adopt an integrative approach synthesizing the objectives of cultural translation with the intrinsic aesthetic characteristics of classical poetry.Through systematic analysis of the cultural semiotics embedded in grass symbolism,the research investigates practical translation techniques at lexical,syntactic,and stylistic dimensions.The findings aim to contribute to the theoretical framework of cultural image translation in Chinese poetic tradition while providing methodological references for cross-cultural interpretation of classical verse.By bridging cultural semiotics with translation praxis,this investigation seeks to advance the intercultural communication of Chinese poetic heritage through nuanced treatment of its botanical symbolism. 展开更多
关键词 classical Chinese poetry GRASS translation strategies cultural image
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Transformer-Based Fusion of Infrared and Visible Imagery for Smoke Recognition in Commercial Areas
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作者 Chongyang Wang Qiongyan Li +2 位作者 Shu Liu Pengle Cheng Ying Huang 《Computers, Materials & Continua》 2025年第9期5157-5176,共20页
With rapid urbanization,fires pose significant challenges in urban governance.Traditional fire detection methods often struggle to detect smoke in complex urban scenes due to environmental interferences and variations... With rapid urbanization,fires pose significant challenges in urban governance.Traditional fire detection methods often struggle to detect smoke in complex urban scenes due to environmental interferences and variations in viewing angles.This study proposes a novel multimodal smoke detection method that fuses infrared and visible imagery using a transformer-based deep learning model.By capturing both thermal and visual cues,our approach significantly enhances the accuracy and robustness of smoke detection in business parks scenes.We first established a dual-view dataset comprising infrared and visible light videos,implemented an innovative image feature fusion strategy,and designed a deep learning model based on the transformer architecture and attention mechanism for smoke classification.Experimental results demonstrate that our method outperforms existing methods,under the condition of multi-view input,it achieves an accuracy rate of 90.88%,precision rate of 98.38%,recall rate of 92.41%and false positive and false negative rates both below 5%,underlining the effectiveness of the proposed multimodal and multi-view fusion approach.The attention mechanism plays a crucial role in improving detection performance,particularly in identifying subtle smoke features. 展开更多
关键词 Multimodal image processing smoke recognition urban safety environmental monitoring
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Hyperspectral imagery quality assessment and band reconstruction using the prophet model
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作者 Ping Ma Jinchang Ren +2 位作者 Zhi Gao Yinhe Li Rongjun Chen 《CAAI Transactions on Intelligence Technology》 2025年第1期47-61,共15页
In Hyperspectral Imaging(HSI),the detrimental influence of noise and distortions on data quality is profound,which has severely affected the following-on analytics and decisionmaking such as land mapping.This study pr... In Hyperspectral Imaging(HSI),the detrimental influence of noise and distortions on data quality is profound,which has severely affected the following-on analytics and decisionmaking such as land mapping.This study presents an innovative framework for assessing HSI band quality and reconstructing the low-quality bands,based on the Prophet model.By introducing a comprehensive quality metric to start,the authors approach factors in both spatial and spectral characteristics across local and global scales.This metric effectively captures the intricate noise and distortions inherent in the HSI data.Subsequently,the authors employ the Prophet model to forecast information within the low-quality bands,leveraging insights from neighbouring high-quality bands.To validate the effectiveness of the authors’proposed model,extensive experiments on three publicly available uncorrected datasets are conducted.In a head-to-head comparison,the framework against six state-ofthe-art band reconstruction algorithms including three spectral methods,two spatialspectral methods and one deep learning method is benchmarked.The authors’experiments also delve into strategies for band selection based on quality metrics and the quality evaluation of the reconstructed bands.In addition,the authors assess the classification accuracy utilising these reconstructed bands.In various experiments,the results consistently affirm the efficacy of the authors’method in HSI quality assessment and band reconstruction.Notably,the authors’approach obviates the need for manually prefiltering of noisy bands.This comprehensive framework holds promise in addressing HSI data quality concerns whilst enhancing the overall utility of HSI. 展开更多
关键词 band reconstruction band quality hyperspectral image(HSI) prophet model
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Attention Driven YOLOv5 Network for Enhanced Landslide Detection Using Satellite Imagery of Complex Terrain
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作者 Naveen Chandra Himadri Vaidya +2 位作者 Suraj Sawant Shilpa Gite Biswajeet Pradhan 《Computer Modeling in Engineering & Sciences》 2025年第6期3351-3375,共25页
Landslide hazard detection is a prevalent problem in remote sensing studies,particularly with the technological advancement of computer vision.With the continuous and exceptional growth of the computational environmen... Landslide hazard detection is a prevalent problem in remote sensing studies,particularly with the technological advancement of computer vision.With the continuous and exceptional growth of the computational environment,the manual and partially automated procedure of landslide detection from remotely sensed images has shifted toward automatic methods with deep learning.Furthermore,attention models,driven by human visual procedures,have become vital in natural hazard-related studies.Hence,this paper proposes an enhanced YOLOv5(You Only Look Once version 5)network for improved satellite-based landslide detection,embedded with two popular attention modules:CBAM(Convolutional Block Attention Module)and ECA(Efficient Channel Attention).These attention mechanisms are incorporated into the backbone and neck of the YOLOv5 architecture,distinctly,and evaluated across three YOLOv5 variants:nano(n),small(s),and medium(m).The experiments use opensource satellite images from three distinct regions with complex terrain.The standard metrics,including F-score,precision,recall,and mean average precision(mAP),are computed for quantitative assessment.The YOLOv5n+CBAM demonstrates the most optimal results with an F-score of 77.2%,confirming its effectiveness.The suggested attention-driven architecture augments detection accuracy,supporting post-landslide event assessment and recovery. 展开更多
关键词 Attention mechanism convolutional neural networks LANDSLIDES remote sensing images YOLOv5
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Comparative Analysis of Deep Learning Models for Banana Plant Detection in UAV RGB and Grayscale Imagery
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作者 Ching-Lung Fan Yu-Jen Chung Shan-Min Yen 《Computers, Materials & Continua》 2025年第9期4627-4653,共27页
Efficient banana crop detection is crucial for precision agriculture;however,traditional remote sensing methods often lack the spatial resolution required for accurate identification.This study utilizes low-altitude U... Efficient banana crop detection is crucial for precision agriculture;however,traditional remote sensing methods often lack the spatial resolution required for accurate identification.This study utilizes low-altitude Unmanned Aerial Vehicle(UAV)images and deep learning-based object detection models to enhance banana plant detection.A comparative analysis of Faster Region-Based Convolutional Neural Network(Faster R-CNN),You Only Look Once Version 3(YOLOv3),Retina Network(RetinaNet),and Single Shot MultiBox Detector(SSD)was conducted to evaluate their effectiveness.Results show that RetinaNet achieved the highest detection accuracy,with a precision of 96.67%,a recall of 71.67%,and an F1 score of 81.33%.The study further highlights the impact of scale variation,occlusion,and vegetation density on detection performance.Unlike previous studies,this research systematically evaluates multi-scale object detection models for banana plant identification,offering insights into the advantages of UAV-based deep learning applications in agriculture.In addition,this study compares five evaluation metrics across the four detection models using both RGB and grayscale images.Specifically,RetinaNet exhibited the best overall performance with grayscale images,achieving the highest values across all five metrics.Compared to its performance with RGB images,these results represent a marked improvement,confirming the potential of grayscale preprocessing to enhance detection capability. 展开更多
关键词 Unmanned Aerial Vehicle image object detection deep learning banana crops
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基于CASI高光谱数据的作物叶面积指数估算 被引量:10
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作者 唐建民 廖钦洪 +3 位作者 刘奕清 杨贵军 冯海宽 王纪华 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2015年第5期1351-1356,共6页
叶面积指数(LAI)的快速估算对于及时了解作物长势、病虫害监测以及产量评估具有重要意义。利用2012年7月7日在黑河流域张掖市获取的CASI高光谱数据,精确提取出了不同作物的光谱反射率,同时结合地面实测数据,对比分析了宽波段和"红... 叶面积指数(LAI)的快速估算对于及时了解作物长势、病虫害监测以及产量评估具有重要意义。利用2012年7月7日在黑河流域张掖市获取的CASI高光谱数据,精确提取出了不同作物的光谱反射率,同时结合地面实测数据,对比分析了宽波段和"红边"植被指数在估算作物LAI方面的潜力,在此基础上,基于波段组合算法,筛选出作物LAI估算的敏感波段,并构建了两个新型光谱指数NDSI和RSI,最后对研究区域作物LAI的空间分布进行了分析。结果表明,在植被覆盖度较低的情况下,宽波段植被指数NDVI对LAI具有较好的估算效果,模型的精度R2与RMSE分别为0.52,0.45(p<0.01);对于"红边"植被指数,由于CIred edge充分考虑了不同的作物类型,其对LAI的估算精度与NDVI一致;利用波段组合算法构建的光谱指数NDSI(569.00,654.80)和RSI(597.6,654.80)对LAI估算的效果要优于NDVI与CIred edge,其中,NDSI(569.00,654.80)主要利用了植被光谱"绿峰"和"红谷"附近的波段,模型估算的精度R2可达0.77(p<0.000 1);根据LAI与NDSI(569.00,654.80)之间的函数关系,绘制作物LAI的空间分布图,经分析,研究区域的西北部LAI值偏低,需增施肥料。研究结果,可为农业管理部门及时掌握作物长势信息、制定施肥策略提供技术支持。 展开更多
关键词 casi高光谱数据 叶面积指数 植被指数 波段组合 空间分布
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整合机载CASI和SASI高光谱数据的北方森林树种填图研究 被引量:8
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作者 刘丽娟 庞勇 +2 位作者 范文义 李增元 李明泽 《遥感技术与应用》 CSCD 北大核心 2011年第2期129-136,共8页
将机载CASI和SASI高光谱数据整合,既可以获取可见光—近红外—短波红外区间连续的窄波段地物光谱,又能得到很高的空间分辨率,为高覆盖度的森林树种识别又增加了一种新方法。但是由于两种传感器的光谱响应不同,接收到的辐射值差异较大,... 将机载CASI和SASI高光谱数据整合,既可以获取可见光—近红外—短波红外区间连续的窄波段地物光谱,又能得到很高的空间分辨率,为高覆盖度的森林树种识别又增加了一种新方法。但是由于两种传感器的光谱响应不同,接收到的辐射值差异较大,如何将两种数据有效整合目前仍是一个难题。CASI和SASI覆盖谱段不同,受大气影响程度也不同,根据植被反射和吸收光谱特性,首先用基于统计模型的经验线性法和基于辐射传输的MODTRAN模型分别对CASI和SASI大气校正,复原地物光谱真实的反射率。然后去除反射率光谱包络线,用Savitzky-Golay滤波函数对归一化后的光谱曲线进行平滑,以去除噪声及异常点,实现CASI和SASI数据(CASI+SASI)的整合。与实测光谱曲线对比发现,整合后的CASI+SASI光谱曲线与实测光谱曲线匹配度较高,并且比单一传感器的光谱信息更丰富,有利于不同树种的区分识别。最后应用光谱微分及曲线匹配技术,选取SVM分类器实现了研究区的树种填图,总体精度达到86.21%,Kappa系数为0.8297,该方法有效可行,为后续的相关研究提供了参考。 展开更多
关键词 机载 高光谱 casi SASI 整合 包络线去除 Savitzky-Golay滤波
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人工智能在小肠息肉图像无创检测领域的研究进展
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作者 张新峰 高子君 +1 位作者 刘晓民 李相生 《北京工业大学学报》 北大核心 2026年第2期148-157,共10页
小肠息肉起病隐匿,临床症状特异性不强,检出有一定难度,内窥镜检查技术是最常用的小肠疾病检查技术,但此技术操作复杂,亦有一定的观察盲区,如盲肠后方、肠瓣膜后方。通过计算机断层扫描(computed tomography,CT)、核磁共振(magnetic res... 小肠息肉起病隐匿,临床症状特异性不强,检出有一定难度,内窥镜检查技术是最常用的小肠疾病检查技术,但此技术操作复杂,亦有一定的观察盲区,如盲肠后方、肠瓣膜后方。通过计算机断层扫描(computed tomography,CT)、核磁共振(magnetic resonance imaging,MRI)等无盲区的非侵入式检测方式进行病变定位识别,具有重要临床意义,利用人工智能技术有望提高小肠息肉诊断的敏感性、准确性和快捷性。鉴于此,分析了人工智能技术在小肠息肉无创检测中的最新研究进展,内容包括:图像分割、小肠息肉三维重建、小肠息肉疾病分类预测。旨在助力提升小肠息肉检测和诊断的准确率;明晰技术发展脉络,为后续研究提供方向。 展开更多
关键词 小肠息肉 医学图像处理 深度学习 图像分割 三维重建
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面向地质应用的航空高光谱CASI-SASI数据大气校正方法对比研究 被引量:12
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作者 叶发旺 王建刚 +1 位作者 邱骏挺 张川 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2019年第9期2677-2685,共9页
蚀变信息提取是高光谱遥感地质应用的重要内容。基于特殊吸收峰的蚀变矿物提取是蚀变信息提取的重要手段。由于大气的吸收和散射作用,为了获得更为真实的地物反射光谱,必须进行大气校正。目前,国内外针对大气校正的对比研究主要集中在... 蚀变信息提取是高光谱遥感地质应用的重要内容。基于特殊吸收峰的蚀变矿物提取是蚀变信息提取的重要手段。由于大气的吸收和散射作用,为了获得更为真实的地物反射光谱,必须进行大气校正。目前,国内外针对大气校正的对比研究主要集中在大气校正前后图像的质量改善、地物分类效果的提升以及校正图像像元光谱与实际地物光谱的相关关系等方面,而对不同校正方法获得的像元光谱与实际光谱吸收峰位的对应情况则很少讨论,这对于依赖吸收峰特征进行蚀变矿物提取的地质遥感极为不利。利用CASI-SASI航空高光谱成像系统,采集了甘肃龙首山地区的航空高光谱遥感数据,并运用ASD光谱仪,对该地区实际地物光谱进行了测量。以此为基础,开展了FLAASH、快速大气校正(QUAC)、经验线(EMPL)等方法大气校正结果的对比研究。通过对比分析,发现FLAASH,QUAC和EMPL均能在一定程度上消除大气的影响,改善航空高光谱遥感的图像质量,但EMPL方法得到的反射率与实际反射率相关性最好。此外,运用人工目视方法开展了实际地物反射光谱的吸收峰位与不同校正方法得到的对应像元反射光谱的吸收峰位的对比研究,发现不同校正方法得到的像元光谱的吸收峰位与实际峰位均存在不同程度的差异,虽然EMPL对吸收峰位的保留效果最好,但依然有“漏峰”的现象。据此,提出运用多种大气校正方法开展综合研究,以提高不同类型的蚀变带定位准确度。 展开更多
关键词 高光谱遥感 casi/SASI 大气校正 对比分析
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基于CASI影像的黑河中游种植结构精细分类研究 被引量:5
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作者 张苗 蒋志荣 +2 位作者 马明国 王志慧 张调风 《遥感技术与应用》 CSCD 北大核心 2013年第2期283-289,共7页
基于CASI高光谱影像资料,计算出NDVI和纹理数据并综合进行SVM(Support VectorMachine)分类,3种信息的组合形成4种分类方案,是为了探讨CASI数据在种植结构精细分类中的应用潜力,为定量研究和监测提供数据基础。数据在分类前利用同步ASD... 基于CASI高光谱影像资料,计算出NDVI和纹理数据并综合进行SVM(Support VectorMachine)分类,3种信息的组合形成4种分类方案,是为了探讨CASI数据在种植结构精细分类中的应用潜力,为定量研究和监测提供数据基础。数据在分类前利用同步ASD数据和CE-318数据进行了辐射定标和大气校正。分类结果与地面实际调查数据对比验证结果表明:①4种分类结果均与地面实际调查情况基本一致,并分别取得了96.78%、97.21%、88.00%、88.38%的分类精度和0.9676、0.9691、0.8674、0.8716的Kappa系数;②CASI数据信息丰富,在植被的精细分类方面具有很大的应用潜力;③结合空间特征信息和NDVI数据可以有效地提高分类精度。 展开更多
关键词 casi 高光谱遥感 SVM 种植结构 黑河中游
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CASI/SASI航空高光谱遥感测量系统及其在铀矿勘查中的初步应用 被引量:37
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作者 叶发旺 刘德长 赵英俊 《世界核地质科学》 CAS 2011年第4期231-236,共6页
介绍了我国首次引进的CASI/SASI航空高光谱遥感测量系统组成及其主要技术指标,并以新疆柯坪地区铀矿勘查为例,阐述了该系统遥感数据获取、数据预处理、铀矿化蚀变矿物填图和野外验证等。研究表明,CASI/SASI航空高光谱遥感测量系统可以... 介绍了我国首次引进的CASI/SASI航空高光谱遥感测量系统组成及其主要技术指标,并以新疆柯坪地区铀矿勘查为例,阐述了该系统遥感数据获取、数据预处理、铀矿化蚀变矿物填图和野外验证等。研究表明,CASI/SASI航空高光谱遥感测量系统可以获取高空间、高光谱分辨率的遥感数据,在新疆柯坪地区大比例尺提取铀矿化蚀变信息方面取得了很好的效果。 展开更多
关键词 casi/SASI航空高光谱测量系统 铀矿勘查 柯坪地区
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CASI/SASI航空高光谱遥感矿物技术研究——以甘肃北山柳园地区为例 被引量:4
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作者 杨清华 吴小娟 +2 位作者 肖政浩 刘肖姬 董沐鑫 《地质力学学报》 CSCD 北大核心 2015年第2期241-251,共11页
能源勘查、岩石矿物识别、矿物丰度制图以及成矿远景区圈定是高光谱技术发展和应用的主要方向。CASI/SASI航空高光谱数据可以在同一平台下同时获取覆盖可见光-近红外-短波红外光谱段的光谱信息,且光谱分辨率和空间分辨率远远优于多光谱... 能源勘查、岩石矿物识别、矿物丰度制图以及成矿远景区圈定是高光谱技术发展和应用的主要方向。CASI/SASI航空高光谱数据可以在同一平台下同时获取覆盖可见光-近红外-短波红外光谱段的光谱信息,且光谱分辨率和空间分辨率远远优于多光谱及星载高光谱数据,所以在矿物蚀变信息提取中具有广泛的应用前景。以柳园研究区为研究对象,对CASI/SASI航空高光谱遥感矿物过程中的关键技术进行了实验研究,确定出航空高光谱矿物蚀变信息提取流程,并对研究区蚀变矿物进行识别、填图。通过与研究区地质资料和前人实地勘探资料对比得出,研究区CASI/SASI航空高光谱遥感蚀变异常结果与现实状况相当吻合。 展开更多
关键词 casi/SASI 预处理 矿物识别 端元选取 矿物填图
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勘探地震学最小二乘偏移成像进展综述
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作者 杨继东 黄建平 +6 位作者 祝贺君 李振春 卢绍平 毛伟建 周辉 秦宁 田坤 《地球与行星物理论评(中英文)》 2026年第3期242-270,共29页
地震偏移成像是地球物理勘探的核心方法之一,在地球内部不连续界面研究、矿产资源勘查、油气勘探开发以及工程地质调查等方面发挥着不可替代的作用.在过去半个世纪中,随着高性能计算和宽频宽方位地震采集技术的飞速发展,地震成像方法经... 地震偏移成像是地球物理勘探的核心方法之一,在地球内部不连续界面研究、矿产资源勘查、油气勘探开发以及工程地质调查等方面发挥着不可替代的作用.在过去半个世纪中,随着高性能计算和宽频宽方位地震采集技术的飞速发展,地震成像方法经历了从传统射线类偏移到波动方程偏移,再到最小二乘偏移和全波形反演成像的跨越式发展.通过构建并求解线性或非线性最优化问题,反演偏移成像技术能够获得地下反射率模型的广义逆,克服了传统偏移方法在非规则采集、有限频带数据和不均衡照明等方面的局限性,显著提升成像分辨率与振幅保真度.本文系统总结了勘探地震学中高精度反演偏移成像的研究进展与前沿动态,重点描述了数据域、成像域与智能化三种线性最小二乘偏移方法的理论基础与方法体系,详细介绍了各类正则化和预条件优化策略的数学原理与应用效果,阐述了非线性全波形反演成像的最新研究成果与发展趋势,为高精度地震成像研究提供理论方法和技术应用参考. 展开更多
关键词 地震成像 最小二乘偏移 全波形反演成像 计算地震学
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CaSi氧化物对Sr_(1-x)La_xFe_(11.6-x)Co_xO_(19)六角铁氧体晶粒形貌及磁性能影响研究 被引量:3
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作者 陈中艳 冯则坤 +1 位作者 詹振华 吴捷 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2014年第1期81-84,共4页
基于传统陶瓷工艺制备Sr1-x Lax Fe11.6-x Cox O19样品,重点研究CaSi氧化物对Sr1-x Lax Fe11.6-x Cox O19预烧料晶粒形貌及磁性能的影响。采用XRD、SEM和VSM分析样品的结构特征、微观形貌及磁特性。微观形貌分析的结果表明CaSi氧化物可... 基于传统陶瓷工艺制备Sr1-x Lax Fe11.6-x Cox O19样品,重点研究CaSi氧化物对Sr1-x Lax Fe11.6-x Cox O19预烧料晶粒形貌及磁性能的影响。采用XRD、SEM和VSM分析样品的结构特征、微观形貌及磁特性。微观形貌分析的结果表明CaSi氧化物可以有效调控预烧料的晶粒形貌,通过优化CaSi氧化物的含量,能够得到理想的微观形貌及高的Mr/Ms。当掺杂量x=0.2时,加入0.15wt%CaCO3和0.2wt%SiO2的添加剂,饱和磁化强度(σs)和矫顽力(HcJ)比未加入CaSi氧化物时分别提高4.76%和6.2%,样品的Mr/Ms在掺杂范围内均有所提高。 展开更多
关键词 casi氧化物 六角铁氧体 微观形貌 磁性能
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用于鱼眼图像自适应矫正的注意力金字塔网络
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作者 张博 李雪 +4 位作者 王白阳 李光健 王国平 潘杨 朱磊 《电光与控制》 北大核心 2026年第1期106-111,共6页
针对鱼眼镜头拍摄图像存在畸变,影响其在目标检测、图像分割等计算机视觉任务中的应用问题,提出了一种用于鱼眼图像自适应矫正的注意力金字塔网络(APFC-Net)。首先,为解决卷积层中特征图缩放导致的边缘和角落信息丢失问题,构建了注意增... 针对鱼眼镜头拍摄图像存在畸变,影响其在目标检测、图像分割等计算机视觉任务中的应用问题,提出了一种用于鱼眼图像自适应矫正的注意力金字塔网络(APFC-Net)。首先,为解决卷积层中特征图缩放导致的边缘和角落信息丢失问题,构建了注意增强空间金字塔(AASP)模块以加强特征提取;其次,考虑到不同区域的畸变程度差异,在失真矫正阶段引入可变形卷积,以自适应处理不同程度的畸变;最后,为解决失真矫正过程中信息细节丢失导致的图像模糊问题,在编码阶段嵌入SimAM注意力机制,以专注图像关键区域。仿真结果表明:APFC-Net在Place 2数据集上优于MLC和SimFIR等方法;相较于PCN方法,其PSNR和SSIM分别提升9.11%和27.14%,验证了模型在图像矫正中的有效性。 展开更多
关键词 鱼眼图像 畸变矫正 机器视觉 深度学习
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