期刊文献+
共找到8,545篇文章
< 1 2 250 >
每页显示 20 50 100
Multi-Dimensional Weight Regulation Network for Remote Sensing Image Dehazing
1
作者 Donghui Zhao Bo Mo 《Journal of Beijing Institute of Technology》 2025年第1期71-90,共20页
This paper introduces a lightweight remote sensing image dehazing network called multidimensional weight regulation network(MDWR-Net), which addresses the high computational cost of existing methods. Previous works, o... This paper introduces a lightweight remote sensing image dehazing network called multidimensional weight regulation network(MDWR-Net), which addresses the high computational cost of existing methods. Previous works, often based on the encoder-decoder structure and utilizing multiple upsampling and downsampling layers, are computationally expensive. To improve efficiency, the paper proposes two modules: the efficient spatial resolution recovery module(ESRR) for upsampling and the efficient depth information augmentation module(EDIA) for downsampling.These modules not only reduce model complexity but also enhance performance. Additionally, the partial feature weight learning module(PFWL) is introduced to reduce the computational burden by applying weight learning across partial dimensions, rather than using full-channel convolution.To overcome the limitations of convolutional neural networks(CNN)-based networks, the haze distribution index transformer(HDIT) is integrated into the decoder. We also propose the physicalbased non-adjacent feature fusion module(PNFF), which leverages the atmospheric scattering model to improve generalization of our MDWR-Net. The MDWR-Net achieves superior dehazing performance with a computational cost of just 2.98×10^(9) multiply-accumulate operations(MACs),which is less than one-tenth of previous methods. Experimental results validate its effectiveness in balancing performance and computational efficiency. 展开更多
关键词 image dehazing remote sensing image network lightweight
在线阅读 下载PDF
Efficient Reconstruction of Spatial Features for Remote Sensing Image-Text Retrieval
2
作者 ZHANG Weihang CHEN Jialiang +3 位作者 ZHANG Wenkai LI Xinming GAO Xin SUN Xian 《Transactions of Nanjing University of Aeronautics and Astronautics》 2025年第1期101-111,共11页
Remote sensing cross-modal image-text retrieval(RSCIR)can flexibly and subjectively retrieve remote sensing images utilizing query text,which has received more researchers’attention recently.However,with the increasi... Remote sensing cross-modal image-text retrieval(RSCIR)can flexibly and subjectively retrieve remote sensing images utilizing query text,which has received more researchers’attention recently.However,with the increasing volume of visual-language pre-training model parameters,direct transfer learning consumes a substantial amount of computational and storage resources.Moreover,recently proposed parameter-efficient transfer learning methods mainly focus on the reconstruction of channel features,ignoring the spatial features which are vital for modeling key entity relationships.To address these issues,we design an efficient transfer learning framework for RSCIR,which is based on spatial feature efficient reconstruction(SPER).A concise and efficient spatial adapter is introduced to enhance the extraction of spatial relationships.The spatial adapter is able to spatially reconstruct the features in the backbone with few parameters while incorporating the prior information from the channel dimension.We conduct quantitative and qualitative experiments on two different commonly used RSCIR datasets.Compared with traditional methods,our approach achieves an improvement of 3%-11% in sumR metric.Compared with methods finetuning all parameters,our proposed method only trains less than 1% of the parameters,while maintaining an overall performance of about 96%. 展开更多
关键词 remote sensing cross-modal image-text retrieval(rsCIR) spatial features channel features contrastive learning parameter effective transfer learning
在线阅读 下载PDF
Remote sensing of air pollution incorporating integrated-path differential-absorption and coherent-Doppler lidar 被引量:2
3
作者 Ze-hou Yang Yong Chen +5 位作者 Chun-li Chen Yong-ke Zhang Ji-hui Dong Tao Peng Xiao-feng Li Ding-fu Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期594-601,共8页
An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and demonstrated.The system incorporates integrated-path differential absorption l... An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and demonstrated.The system incorporates integrated-path differential absorption lidar(DIAL) and coherent-doppler lidar(CDL) techniques using a dual tunable TEA CO_(2)laser in the 9—11 μm band and a 1.55 μm fiber laser.By combining the principles of differential absorption detection and pulsed coherent detection,the system enables agile and remote sensing of atmospheric pollution.Extensive static tests validate the system’s real-time detection capabilities,including the measurement of concentration-path-length product(CL),front distance,and path wind speed of air pollution plumes over long distances exceeding 4 km.Flight experiments is conducted with the helicopter.Scanning of the pollutant concentration and the wind field is carried out in an approximately 1 km slant range over scanning angle ranges from 45°to 65°,with a radial resolution of 30 m and10 s.The test results demonstrate the system’s ability to spatially map atmospheric pollution plumes and predict their motion and dispersion patterns,thereby ensuring the protection of public safety. 展开更多
关键词 Differential absorption LIDAR COHERENT Doppler lidar remoting sensing Atmospheric pollution
在线阅读 下载PDF
Untethered Micro/Nanorobots for Remote Sensing:Toward Intelligent Platform
4
作者 Qianqian Wang Shihao Yang Li Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期450-483,共34页
Untethered micro/nanorobots that can wirelessly control their motion and deformation state have gained enormous interest in remote sensing applications due to their unique motion characteristics in various media and d... Untethered micro/nanorobots that can wirelessly control their motion and deformation state have gained enormous interest in remote sensing applications due to their unique motion characteristics in various media and diverse functionalities.Researchers are developing micro/nanorobots as innovative tools to improve sensing performance and miniaturize sensing systems,enabling in situ detection of substances that traditional sensing methods struggle to achieve.Over the past decade of development,significant research progress has been made in designing sensing strategies based on micro/nanorobots,employing various coordinated control and sensing approaches.This review summarizes the latest developments on micro/nanorobots for remote sensing applications by utilizing the self-generated signals of the robots,robot behavior,microrobotic manipulation,and robot-environment interactions.Providing recent studies and relevant applications in remote sensing,we also discuss the challenges and future perspectives facing micro/nanorobots-based intelligent sensing platforms to achieve sensing in complex environments,translating lab research achievements into widespread real applications. 展开更多
关键词 Micro/nanorobot remote sensing Wireless control SELF-PROPULSION Actuation at small scales
在线阅读 下载PDF
Remote sensing image encryption algorithm based on novel hyperchaos and an elliptic curve cryptosystem
5
作者 田婧希 金松昌 +2 位作者 张晓强 杨绍武 史殿习 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期292-304,共13页
Remote sensing images carry crucial ground information,often involving the spatial distribution and spatiotemporal changes of surface elements.To safeguard this sensitive data,image encryption technology is essential.... Remote sensing images carry crucial ground information,often involving the spatial distribution and spatiotemporal changes of surface elements.To safeguard this sensitive data,image encryption technology is essential.In this paper,a novel Fibonacci sine exponential map is designed,the hyperchaotic performance of which is particularly suitable for image encryption algorithms.An encryption algorithm tailored for handling the multi-band attributes of remote sensing images is proposed.The algorithm combines a three-dimensional synchronized scrambled diffusion operation with chaos to efficiently encrypt multiple images.Moreover,the keys are processed using an elliptic curve cryptosystem,eliminating the need for an additional channel to transmit the keys,thus enhancing security.Experimental results and algorithm analysis demonstrate that the algorithm offers strong security and high efficiency,making it suitable for remote sensing image encryption tasks. 展开更多
关键词 hyperchaotic system elliptic curve cryptosystem(ECC) 3D synchronous scrambled diffusion remote sensing image unmanned aerial vehicle(UAV)
在线阅读 下载PDF
SDaDCS Remote Sensing Target Detection Algorithm
6
作者 Meijing Gao Yunjia Xie +6 位作者 Xiangrui Fan Kunda Wang Sibo Chen Huanyu Sun Bingzhou Sun Xu Chen Ning Guan 《Journal of Beijing Institute of Technology》 EI CAS 2024年第6期556-569,共14页
In the field of remote sensing,the rapid and accurate acquisition of the category and location of airplanes has emerged as a prominent research.However,remote sensing fuzzy imaging and complex environmental interferen... In the field of remote sensing,the rapid and accurate acquisition of the category and location of airplanes has emerged as a prominent research.However,remote sensing fuzzy imaging and complex environmental interference affect airplane detection.Besides,the inconsistency in the size of remote sensing images and the low accuracy of small target detection are crucial challenges that need to be addressed.To tackle these issues,we propose a novel network SDaDCS(SAHI-data augmentation-dilation-channel and spatial attention)based on YOLOX model and the slicing aided hyper inference(SAHI)framework,a new data augmentation technique and dilation-channel and spatial(DCS)attention mechanism.Initially,we create a remote sensing dataset for airplane targets and introduce a new data augmentation technique based on the Rotate-Mixup and mixed data augmentation to enhance data diversity.The DCS attention mechanism,which comprises the dilated convolution block,channel attention and spatial attention,is designed to bolster the feature extraction and discrimination of the network.To address the challenges arised by the difficulties of detecting small targets,we integrate the YOLOX model with the SAHI framework.Experiment results show that,when compared to the original YOLOX model,the proposed SDaDCS remote sensing target detection algorithm enhances overall accuracy by 13.6%.The experimental results validate the effectiveness of the proposed algorithm. 展开更多
关键词 remote sensing target detection SDaDCS small target detection slicing aided hyper inference(SAHI) DCS attention mechanism
在线阅读 下载PDF
Remote sensing of atmospheric duct parameters using simulated annealing 被引量:2
7
作者 赵小峰 黄思训 +1 位作者 项杰 施伟来 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第9期468-475,共8页
Simulated annealing is one of the robust optimization schemes. Simulated annealing mimics the annealing process of the slow cooling of a heated metal to reach a stable minimum energy state. In this paper, we adopt sim... Simulated annealing is one of the robust optimization schemes. Simulated annealing mimics the annealing process of the slow cooling of a heated metal to reach a stable minimum energy state. In this paper, we adopt simulated annealing to study the problem of the remote sensing of atmospheric duct parameters for two different geometries of propagation measurement. One is from a single emitter to an array of radio receivers (vertical measurements), and the other is from the radar clutter returns (horizontal measurements). Basic principles of simulated annealing and its applications to refractivity estimation are introduced. The performance of this method is validated using numerical experiments and field measurements collected at the East China Sea. The retrieved results demonstrate the feasibility of simulated annealing for near real-time atmospheric refractivity estimation. For comparison, the retrievals of the genetic algorithm are also presented. The comparisons indicate that the convergence speed of simulated annealing is faster than that of the genetic algorithm, while the anti-noise ability of the genetic algorithm is better than that of simulated annealing. 展开更多
关键词 remote sensing refractivity estimation electromagnetic wave propagation SIMULATEDANNEALING
在线阅读 下载PDF
Identification of Contamination Information of Vegetation in Coal Mines Based on Hyperspectral Remote Sensing Data 被引量:4
8
作者 ZHANG Jie-lin CAO Dai-yong 《Journal of China University of Mining and Technology》 EI 2005年第3期213-217,共5页
The development and application of the hyper-spectral remote sensing (HRS) in the environment investiga-tion and evaluation of coal mines have been discussed in detail. By using Hyperion HRS technology and field spect... The development and application of the hyper-spectral remote sensing (HRS) in the environment investiga-tion and evaluation of coal mines have been discussed in detail. By using Hyperion HRS technology and field spectrummeasuring and integrating traditional geological method as well as laboratory chemical measurement, the absorptionspectrum features and the spectral variation rules of vegetation caused by coal mine waste piles were studied. Based onthe spectral modeling methods and Vegetation Red Edge Parameter (VREP), the diagnose spectra information andspectral variation parameter were extracted, and the mapping methods of VREP were researched. The spatial distribu-tions of contaminative vegetation have been quickly found out.This study has provided technical supports for the envi-ronment investigation and pollution management of coal mines. 展开更多
关键词 Hyper-spectral remote sensing coal mines contamination information vegetation red edge parameter
在线阅读 下载PDF
Remote sensing of subtropical tree diversity:The underappreciated roles of the practical definition of forest canopy and phenological variation
9
作者 Yongchao Liu Ruyun Zhang +11 位作者 Chen-Feng Lin Zhaochen Zhang Ran Zhang Kankan Shang Mingshui Zhao Jingyue Huang Xiaoning Wang You Li Yulin Zeng Yun-Peng Zhao Jian Zhang Dingliang Xing 《Forest Ecosystems》 SCIE CSCD 2023年第3期378-386,共9页
Tree species diversity is vital for maintaining ecosystem functions,yet our ability to map the distribution of tree diversity is limited due to difficulties in traditional field-based approaches.Recent developments in... Tree species diversity is vital for maintaining ecosystem functions,yet our ability to map the distribution of tree diversity is limited due to difficulties in traditional field-based approaches.Recent developments in spaceborne remote sensing provide unprecedented opportunities to map and monitor tree diversity more efficiently.Here we built partial least squares regression models using the multispectral surface reflectance acquired by Sentinel-2 satellites and the inventory data from 74 subtropical forest plots to predict canopy tree diversity in a national natural reserve in eastern China.In particular,we evaluated the underappreciated roles of the practical definition of forest canopy and phenological variation in predicting tree diversity by testing three different definitions of canopy trees and comparing models built using satellite imagery of different seasons.Our best models explained 42%–63%variations in observed diversities in cross-validation tests,with higher explanation power for diversity indices that are more sensitive to abundant species.The models built using imageries from early spring and late autumn showed consistently better fits than those built using data from other seasons,highlighting the significant role of transitional phenology in remotely sensing plant diversity.Our results suggested that the cumulative diameter(60%–80%)of the biggest trees is a better way to define the canopy layer than using the subjective fixeddiameter-threshold(5–12 cm)or the cumulative basal area(90%–95%)of the biggest trees.Remarkably,these approaches resulted in contrasting diversity maps that call attention to canopy structure in remote sensing of tree diversity.This study demonstrates the potential of mapping and monitoring tree diversity using the Sentinal-2 data in species-rich forests. 展开更多
关键词 Canopy structure Multispectral remote sensing Seasonal phenology Subtropical forest Tree species diversity
在线阅读 下载PDF
OBH-RSI:Object-Based Hierarchical Classification Using Remote Sensing Indices for Coastal Wetland
10
作者 Zhaoyang Lin Jianbu Wang +4 位作者 Wei Li Xiangyang Jiang Wenbo Zhu Yuanqing Ma Andong Wang 《Journal of Beijing Institute of Technology》 EI CAS 2021年第2期159-171,共13页
With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective m... With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective method.The object-based hierarchical classification using remote sensing indices(OBH-RSI)for coastal wetland is proposed to achieve fine classification of coastal wetland.First,the original categories are divided into four groups according to the category characteristics.Second,the training and test maps of each group are extracted according to the remote sensing indices.Third,four groups are passed through the classifier in order.Finally,the results of the four groups are combined to get the final classification result map.The experimental results demonstrate that the overall accuracy,average accuracy and kappa coefficient of the proposed strategy are over 94%using the Yellow River Delta dataset. 展开更多
关键词 Yellow River Delta vegetation index object-based hierarchical classification WETLAND multi-source remote sensing
在线阅读 下载PDF
Dynamic of Chinas cultivated land and landcover changes of its typical regions based on remote sensing data 被引量:1
11
作者 张佳华 董文杰 +2 位作者 王长耀 刘纪远 姚凤梅 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第3期183-186,210,共5页
Using the multi-temporal Landsat data and survey data of national resources, the authors studied the dynamics of cultivated land and landcover changes of typical ecological regions in China. The results of investigati... Using the multi-temporal Landsat data and survey data of national resources, the authors studied the dynamics of cultivated land and landcover changes of typical ecological regions in China. The results of investigation showed that the whole distribution of the cultivated land shifted to Northeast and Northwest China, and as a result, the ecological quality of cultivated land dropped down. The seacoast and cultivated land in the area of Yellow River Mouth expanded by an increasing rate of 0.73 kma-1, with a depositing rate of 2.1 kma-1. The desertification area of the dynamic of Horqin Sandy Land increased from 60.02% of the total land area in1970s to 64.82% in1980s but decreased to 54.90% in early 1990s. As to the change of North Tibet lakes, the water area of the Namu Lake decreased by 38.58 km2 from year 1970 to 1988, with a decreasing rate of 2.14 km2a-1. 展开更多
关键词 remote sensing data Cultivated land Landcover change Typical ecological regions China
在线阅读 下载PDF
Assessment of degraded mattoral land using remote sensing im-agery in Guadalteba Area,Spain
12
作者 邢艳秋 王立海 Eduard Westinga 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第2期145-149,i003,共6页
Natural land cover information is important for analysing and understanding of the current terrestrial situation, especially in the study area that is facing the environmental deteriorating increasingly. The study com... Natural land cover information is important for analysing and understanding of the current terrestrial situation, especially in the study area that is facing the environmental deteriorating increasingly. The study combined the remote sensing Aster data and ground truth to improve 2001 land cover map of Guadalteba area in Spain, and increased the accuracy from 47% to 70%. The general land cover map produced about the Guadalteba study area outlines the distribution of the vegetation type and the current natural land cover in the area. Based on this improved general land cover map, the natural cover map gave an indication of the present location of nature and agriculture areas. The shrub land degradation map identified location of various shrub/matorral areas and different levels of degradation. The further analysis and discussion were done. The output maps indicated that much of the natural cover mostly dominated by formations of shrubs has been changed to agriculture and other land uses. It is observed that shrubland covers a small percentage, approximately 9% of the study area, due to land degradation in most parts caused by human interfere. Keywords Accuracy assessment - Aster - Land cover map - Matorral degradation map - Remote Sensing CLC number S757.3 Document code A Foundation item: This paper was partly sponsored by NFP (Netherlands Feliowship Program) and National Strategic Project “Environmentally Sound Forest Management Techniques and Models in Natural Forest in Northeast China” (2001BA510B0702) respectively.Biography: XING Yan-qiu (1970-), female, Lecturer, in College of Engi neering and technology Northeast Forestry University. Harbin 150040. P. R. ChinaResponsible editor: Song Funan 展开更多
关键词 Accuracy assessment ASTER Land cover map Matorral degradation map remote sensing
在线阅读 下载PDF
Drone remote sensing for forestry research and practices 被引量:26
13
作者 Lina Tang Guofan Shao 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第4期791-797,共7页
Drones of various shapes, sizes, and functionalities have emerged over the past few decades, and their civilian applications are becoming increasingly appealing. Flexible, low-cost, and high-resolution remote sensing ... Drones of various shapes, sizes, and functionalities have emerged over the past few decades, and their civilian applications are becoming increasingly appealing. Flexible, low-cost, and high-resolution remote sensing systems that use drones as platforms are important for filling data gaps and supplementing the capabilities of crewed/manned aircraft and satellite remote sensing systems. Here, we refer to this growing remote sensing ini- tiative as drone remote sensing and explain its unique advantages in forestry research and practices. Furthermore, we summarize the various approaches of drone remote sensing to surveying forests, mapping canopy gaps, mea- suring forest canopy height, tracking forest wildfires, and supporting intensive forest management. The benefits of drone remote sensing include low material and operational costs, flexible control of spatial and temporal resolution, high-intensity data collection, and the absence of risk to crews. The current forestry applications of drone remote sensing are still at an experimental stage, but they are expected to expand rapidly. To better guide the development of drone remote sensing for sustainable forestry, it isimportant to systematically and continuously conduct comparative studies to determine the appropriate drone remote sensing technologies for various forest conditions and/or forestry applications. 展开更多
关键词 Drone - remote sensing UAV UAS UA -RPA· Forest
在线阅读 下载PDF
A commentary review on the use of normalized diff erence vegetation index(NDVI)in the era of popular remote sensing 被引量:31
14
作者 Sha Huang Lina Tang +2 位作者 Joseph P.Hupy Yang Wang Guofan Shao 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第1期1-6,共6页
The Normalized Diff erence Vegetation Index(NDVI),one of the earliest remote sensing analytical products used to simplify the complexities of multi-spectral imagery,is now the most popular index used for vegetation as... The Normalized Diff erence Vegetation Index(NDVI),one of the earliest remote sensing analytical products used to simplify the complexities of multi-spectral imagery,is now the most popular index used for vegetation assessment.This popularity and widespread use relate to how an NDVI can be calculated with any multispectral sensor with a visible and a near-IR band.Increasingly low costs and weights of multispectral sensors mean they can be mounted on satellite,aerial,and increasingly—Unmanned Aerial Systems(UAS).While studies have found that the NDVI is effective for expressing vegetation status andquantified vegetation attributes,its widespread use and popularity,especially in UAS applications,carry inherent risks of misuse with end users who received little to no remote sensing education.This article summarizes the progress of NDVI acquisition,highlights the areas of NDVI application,and addresses the critical problems and considerations in using NDVI.Detailed discussion mainly covers three aspects:atmospheric eff ect,saturation phenomenon,and sensor factors.The use of NDVI can be highly eff ective as long as its limitations and capabilities are understood.This consideration is particularly important to the UAS user community. 展开更多
关键词 NDVI Atmospheric eff ect Saturation phenomenon Calibration MULTISPECTRAL Near infrared UAS Drone remote sensing
在线阅读 下载PDF
Estimating and mapping forest biomass in northeast China using joint forest resources inventory and remote sensing data 被引量:5
15
作者 Xinchuang Wang Shidong Wang Limin Dai 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第3期789-803,共15页
Being able to accurately estimate and map forest biomass at large scales is important for a better understanding of the terrestrial carbon cycle and for improving the effectiveness of forest management. In this study,... Being able to accurately estimate and map forest biomass at large scales is important for a better understanding of the terrestrial carbon cycle and for improving the effectiveness of forest management. In this study, forest plot sample data, forest resources inventory(FRI) data, and SPOT Vegetation(SPOT-VGT) normalized difference vegetation index(NDVI) data were used to estimate total forest biomass and spatial distribution of forest biomass in northeast China(with 1 km resolution). Total forest biomass at both county and provincial scales was estimated using FRI data of 11 different forest types obtained by sampling 1156 forest plots, and newly-created volume to biomass conversion models. The biomass density at the county scale and SPOT-VGT NDVI data were used to estimate the spatial distribution of forest biomass. The results suggest that the total forest biomass was 2.4 Pg(1 Pg = 10g), with an average of 77.2 Mg ha, during the study period. Forests having greater biomass density were located in the middle mountain ranges in the study area. Human activities affected forest biomass at different elevations, slopes and aspects. The results suggest that the volume to biomass conversion models that could be developed using more plot samples and more detailed forest type classifications would be better suited for the study area and would provide more accurate biomass estimates. Use of both FRI and remote sensing data allowed the down-scaling of regional forest biomass statistics to forest cover pixels to produce a relatively fineresolution biomass map. 展开更多
关键词 Forest biomass Biomass density Spatial distribution Human disturbance remote sensing
在线阅读 下载PDF
Digital Watermarking Secure Scheme for Remote Sensing Image Protection 被引量:9
16
作者 Guanghui Yuan Qi Hao 《China Communications》 SCIE CSCD 2020年第4期88-98,共11页
As a means of copyright protection for multimedia data, digital watermarking technology has attracted more and more attention in various research fields. Researchers have begun to explore the feasibility of applying i... As a means of copyright protection for multimedia data, digital watermarking technology has attracted more and more attention in various research fields. Researchers have begun to explore the feasibility of applying it to remote sensing data recently. Because of the particularity of remote sensing image, higher requirements are put forward for its security and management, especially for the copyright protection, illegal use and authenticity identification of remote sensing image data. Therefore, this paper proposes to use image watermarking technology to achieve comprehensive security protection of remote sensing image data, while the use of cryptography technology increases the applicability and security of watermarking technology. The experimental results show that the scheme of remote sensing image digital watermarking technology has good performance in the imperceptibility and robustness of watermarking. 展开更多
关键词 data security WATERMARK remote sensing image PROTECTION
在线阅读 下载PDF
Improved strategy for estimating stem volume and forest biomass using moderate resolution remote sensing data and GIS 被引量:10
17
作者 Arief Wijaya Sandi Kusnadi +1 位作者 Richard Gloaguen Hermann Heilmeier 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第1期1-12,I0001,共13页
This study presents the utility of remote sensing (RS), GIS and field observation data to estimate above ground biomass (AGB) and stem volume over tropical forest environment. Application of those data for the mod... This study presents the utility of remote sensing (RS), GIS and field observation data to estimate above ground biomass (AGB) and stem volume over tropical forest environment. Application of those data for the modeling of forest properties is site specific and highly uncertain, thus further study is encouraged. In this study we used 1460 sampling plots collected in 16 transects measuring tree diameter (DBH) and other forest properties which were useful for the biomass assessment. The study was carded out in tropical forest region in East Kalimantan, Indo- nesia. The AGB density was estimated applying an existing DBH - biomass equation. The estimate was superimposed over the modified GIS map of the study area, and the biomass density of each land cover was calculated. The RS approach was performed using a subset of sample data to develop the AGB and stem volume linear equation models. Pearson correlation statistics test was conducted using ETM bands reflectance, vegetation indices, image transform layers, Principal Component Analysis (PCA) bands, Tasseled Cap (TC), Grey Level Co-Occurrence Matrix (GLCM) texture features and DEM data as the predictors. Two linear models were generated from the significant RS data. To analyze total biomass and stem volume of each land cover, Landsat ETM images from 2000 and 2003 were preprocessed, classified using maximum likelihood method, and filtered with the majority analysis. We found 158±16 m^3.ha^-1 of stem volume and 168±15 t.ha^-1 of AGB estimated from RS approach, whereas the field measurement and GIS estimated 157±92 m^3.ha^-1 and 167±94 t.ha^-1 of stem volume and AGB, respectively. The dynamics of biomass abundance from 2000 to 2003 were assessed from multi temporal ETM data and we found a slightly declining trend of total biomass over these periods. Remote sensing approach estimated lower biomass abundance than did the GIS and field measurement data. The earlier approach predicted 10.5 Gt and 10.3 Gt of total biomasses in 2000 and 2003, while the later estimated 11.9 Gt and 11.6 Gt of total biomasses, respectively. We found that GLCM mean texture features showed markedly strong correlations with stem volume and biomass. 展开更多
关键词 above ground biomass stem volume remote sensing GIS field observation data
在线阅读 下载PDF
Satellite remote-sensing technologies used in forest fire management 被引量:7
18
作者 TIANXiao-rui DouglasJ.Mcrae SHULi-fu WANGMing-yu LIHong 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第1期73-78,i004,共7页
Satellite remote sensing has become a primary data source for fire danger rating prediction, fuel and fire mapping, fire monitoring, and fire ecology research. This paper summarizes the research achievements in these ... Satellite remote sensing has become a primary data source for fire danger rating prediction, fuel and fire mapping, fire monitoring, and fire ecology research. This paper summarizes the research achievements in these research fields, and discusses the future trend in the use of satellite remote-sensing techniques in wildfire management. Fuel-type maps from remote-sensing data can now be produced at spatial and temporal scales quite adequate for operational fire management applications. US National Oceanic and Atmospheric Administration (NOAA) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellites are being used for fire detection worldwide due to their high temporal resolution and ability to detect fires in remote regions. Results can be quickly presented on many Websites providing a valuable service readily available to fire agency. As cost-effective tools, satellite remote-sensing techniques play an important role in fire mapping. Improved remote-sensing techniques have the potential to date older fire scars and provide estimates of burn severity. Satellite remote sensing is well suited to assessing the extent of biomass burning, a prerequisite for estimating emissions at regional and global scales, which are needed for better understanding the effects of fire on climate change. The types of satellites used in fire research are also discussed in the paper. Suggestions on what remote-sensing efforts should be completed in China to modernize fire management technology in this country are given. 展开更多
关键词 Satellite remote sensing Fire management Fuel mapping Fire detection REVIEW
在线阅读 下载PDF
Analysis of Urban Expansion and Driving Forces in Xuzhou City Based on Remote Sensing 被引量:15
19
作者 HU Zhao-ling DU Pei-jun GUO Da-zhi 《Journal of China University of Mining and Technology》 EI 2007年第2期267-271,共5页
Based on satellite remote sensing TM/ETM+ images of Xuzhou city,land use forms of the city in 1987,1994 and 2000 were extracted by using a neural network classification method. The expansion contribution rate and annu... Based on satellite remote sensing TM/ETM+ images of Xuzhou city,land use forms of the city in 1987,1994 and 2000 were extracted by using a neural network classification method. The expansion contribution rate and annual expansion intensity index of each administrative district have been calculated and the contribution rate matrices and spatial distribution maps of land use changes were obtained. Based on the above analysis,the characteristics of urban expansion from 1987 to 2000 have been explored. From 1987 to 1994,the expansion contribution rate of Quanshan dis-trict reached 46.80%,the highest in all administrative districts of Xuzhou city; Tongshan town was in a high-speed ex-pansion period; both Quanshan and Yunlong districts were experiencing fast-speed expansion periods while the entire city was expanding at a medium-speed with an annual expansion intensity index of 0.98; the city spread eastwards and southwards. From 1994 to 2000,the expansion contribution rate of Quanshan district reached 43.67%,the highest in Xuzhou; the entire city was in a medium-speed expansion period with an annual expansion intensity index of 1.04; the city has rapidly been extended towards the southeast. According to the contribution rate matrices of land use changes,urban expansion mainly usurps cropland and woodland. A quantitative analysis found that population growth,indus-trialization and economic development are the primary driving forces behind urban expansion. 展开更多
关键词 remote sensing urban expansion driving force Xuzhou city
在线阅读 下载PDF
A two-scale approach for estimating forest aboveground biomass with optical remote sensing images in a subtropical forest of Nepal 被引量:2
20
作者 Upama A.Koju Jiahua Zhang +4 位作者 Shashish Maharjan Sha Zhang Yun Bai Dinesh B.I.P.Vijayakumar Fengmei Yao 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第6期2119-2136,共18页
Forests account for 80%of the total carbon exchange between the atmosphere and terrestrial ecosystems.Thus,to better manage our responses to global warming,it is important to monitor and assess forest aboveground carb... Forests account for 80%of the total carbon exchange between the atmosphere and terrestrial ecosystems.Thus,to better manage our responses to global warming,it is important to monitor and assess forest aboveground carbon and forest aboveground biomass(FAGB).Different levels of detail are needed to estimate FAGB at local,regional and national scales.Multi-scale remote sensing analysis from high,medium and coarse spatial resolution data,along with field sampling,is one approach often used.However,the methods developed are still time consuming,expensive,and inconvenient for systematic monitoring,especially for developing countries,as they require vast numbers of field samples for upscaling.Here,we recommend a convenient two-scale approach to estimate FAGB that was tested in our study sites.The study was conducted in the Chitwan district of Nepal using GeoEye-1(0.5 m),Landsat(30 m)and Google Earth very high resolution(GEVHR)Quickbird(0.65 m)images.For the local scale(Kayerkhola watershed),tree crowns of the area were delineated by the object-based image analysis technique on GeoEye images.An overall accuracy of 83%was obtained in the delineation of tree canopy cover(TCC)per plot.A TCC vs.FAGB model was developed based on the TCC estimations from GeoEye and FAGB measurements from field sample plots.A coefficient of determination(R2)of 0.76 was obtained in the modelling,and a value of 0.83 was obtained in the validation of the model.To upscale FAGB to the entire district,open source GEVHR images were used as virtual field plots.We delineated their TCC values and then calculated FAGB based on a TCC versus FAGB model.Using the multivariate adaptive regression splines machine learning algorithm,we developed a model from the relationship between the FAGB of GEVHR virtual plots with predictor parameters from Landsat 8 bands and vegetation indices.The model was then used to extrapolate FAGB to the entire district.This approach considerably reduced the need for field data and commercial very high resolution imagery while achieving two-scale forest information and FAGB estimates at high resolution(30 m)and accuracy(R2=0.76 and 0.7)with minimal error(RMSE=64 and 38 tons ha-1)at local and regional scales.This methodology is a promising technique for cost-effective FAGB and carbon estimations and can be replicated with limited resources and time.The method is especially applicable for developing countries that have low budgets for carbon estimations,and it is also applicable to the Reducing Emissions from Deforestation and Forest Degradation(REDD?)monitoring reporting and verification processes. 展开更多
关键词 FOREST ABOVEGROUND biomass Google Earth IMAGERY MULTI-SCALE remote sensing Virtual PLOT Optical IMAGERY
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部