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Monitoring of rice crop using ENVISAT ASAR data

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Science China Earth Sciences 2006年第7期49卷 755-763页

作者： DONG Yanfang1, 2, SUN Guoqing1,3 & PANG Yong4 1. State Key Laboratory of remote sensing Science, Institute of remote sensing Applications, Chinese Academy of Sciences, Beijing 100101, China 2. Graduate University of Chinese Academy of Sciences, Beijing 100039, China 3. department of Geography, University of Maryland, College Park, MD 20742, USA 4. Forest remote sensing Lab, Research Institute of Forest resource and Information Technology, Chinese Academy of For-estry, Beijing 100091, China State Key Laboratory of remote sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China department of Geography University of Maryland College Park USA Forest remote sensing Lab Research Institute of Forest Resource and Information Technology Chinese Academy of Forestry Beijing China

Because of the cloudy conditions during the rice growth period, rice is one of the agri-cultural crops most suited to monitoring with the SAR instruments. Backscatter response measured by SAR is correlated with rice conditions, including height, density, biomass and structure, which are variable at different growing stages. In this paper, multi-date ENVISAT ASAR Alternating Polarization Mode (APMode) imageries were acquired during the rice crop growing cycle. At the same time, the rice parameters were measured in field. A continuous canopy model was used to compute the back-scattering from rice fields during the growth cycle, and the relationship between rice parameters and radar backscattering coefficients from both ASAR and modeling was analyzed. The effects of polari-zation, incidence angle and polarization on radar backscattering coefficients were analyzed. It was found that simulated radar backscatter has similar trends as ASAR data. This will be meaningful for the further research of rice parameters estimation from ASAR data. Different features show signifi-cantly different signatures in ASAR images and they follow some certain laws, so rice area can be accurately mapped by using multi-temporal SAR images, then rice yield can be estimated.

关键词： rice, ASAR, radar backscattering, model.

Synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data

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Science China(Technological Sciences) 2008年第S2期51卷 176-187页

作者： BAO YunFei1,2,CAO ChunXiang1,ZHANG Hao1,CHEN ErXue3,HE QiSheng1,2,HUANG HuaBing1,LI ZengYuan3,LI XiaoWen1,4 & GONG Peng1 1 State Key Laboratory of remote sensing Science,jointly sponsored by the Institute for remote sensing Applications of Chinese Academy of Sciences and Beijing Normal University,Beijing 100101,China 2 Graduate University of the Chinese Academy of Sciences,Beijing 100049,China 3 Institute of Forest resource Information Technique,the Chinese Academy of Forestry,Beijing 100091,China 4 Research Center for remote sensing and GIS,department of Geography and Beijing Key Laboratory for remote sensing of Environment and Digital Sites,Beijing Normal University,Beijing 100875,China State Key Laboratory of remote sensing Science jointly sponsored by the Institute for Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing China Graduate University of the Chinese Academy of Sciences Beijing China Institute of Forest resource Information Technique the Chinese Academy of Forestry Beijing China Research Center for remote sensing and GIS Department of Geography and Beijing Key Laboratory for Remote Sensing of Environment and Digital Sites Beijing Normal University Beijing China

We proposed a method to separate ground points and vegetation points from discrete return,small footprint airborne laser scanner data,called skewness change *** method,which makes use of intensity of laser scanner data,is especially applicable in steep,and forested *** does not take slope of forested area into account,while other algorithms consider the change of slope in steep forested *** ground points and vegetation points can be used to estimate digital terrain model(DTM) and fractional vegetation cover,respectively.A few vegetation points which were classified into the ground points were removed as noise before the generation of *** method was tested in a test area of 10000 square meters.A LiteMapper -5600 laser system was used and a flight was carried out over a ground of 700―800 *** this tested area,a total number of 1546 field measurement ground points were measured with a total station TOPCON GTS-602 and TOPCON GTS -7002 for validation of DTM and the mean error value is -18.5 cm and the RMSE(root mean square error) is ±20.9 cm.A data trap sizes of 4m in diameter from airborne laser scanner data was selected to compute vegetation fraction *** of fractional vegetation cover was carried out using 15 hemispherical photographs,which are georeferenced to centimeter accuracy by differential *** gap fraction was computed over a range of zenith angles 10° using the gap light analyzer(GLA) from each hemispherical *** R2 for the regression of fractional vegetation cover from these ALS data and the respective field measurements is *** this study presents a method for synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data.

关键词： LIDAR intensity skewness synchronous DTM fractional vegetation cover

New processing method for fire forecast parameters

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Journal of Coal Science & Engineering(China) 2004年第1期10卷 41-44页

作者：余明高袁东升贾海林李定启张建民贾跃荣 department of resource and Material Engineering Jiaozuo Institute of Technology Jiaozuo 454000 China Beijing remote sensing Corp. Beijing 100085 China

The time forecast system of coal spontaneous combustion was described based on the KJ-90 mine environmental monitoring system in Hulipo Mine, Luzhou, Sichuan Province. In the system, CO and O2 sensor are added, and special-purpose microcomputer and software are equipped. By means of the system, the fluctuation laws of fire forecast parameters were observed in the process of coal-cutting, blast, exogenous mine fire and working face air quantity variation. This paper puts forward data processing method based on the Raita method.

关键词： fire forecast parameter coal spontaneous combustion fluctuation law

Assessment of Mangrove Covers Change and Biomass in Mida creek, Kenya

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Open Journal of Forestry 2014年第4期4卷 398-413页

作者： Fikir Alemayehu Onwonga Richard Kinyanjui Mwangi James Oliverv Wasonga department of Land resource Management and Agricultural Technology College of Agriculture and Veterinary Science University of Nairobi Kenya department of resource surveys and remote sensing Nairobi Kenya

This study uses old aerial photographs, current high resolution satellite images and ground truthing to analyze the patterns and dynamics of Mida Creek mangrove forest changes over 41 years from 1969-2010. A non-distractive method was used to collect data on 25 sample plots and 934 trees were measured to estimate the above ground biomass and carbon stock of the forest. General published allometric equations with variables of Diameter at Breast Height (DBH) and wood density (ρ) which were species specific were used to estimate above ground biomass. A decline in mangrove cover (16%) took place between 1969 and 1989 and between 1989 and 2010 an increment was observed in mangrove cover (1452.5 ha in 1989 to 1655.7 ha in 2010). Signs of degradation within the mangrove forest were observed in 2010 in which the degraded land covered 8.8 ha. The total above ground biomass and carbon estimated on the 25 plots was 296.14 ton·ha-1 and 148.07 ton·ha-1 respectively. Mida Creek mangrove forest is largely dominated by the presence of Rhizophora mucronata and Ceriop tagal and the regeneration of these two species is very high. If the present dominance of the two species continues it will affect the species composition of the current mangrove forest. This study recommends a better management plan for the mangrove forest through increasing involvement of the surrounding communities. Furthermore, there should be a way to control selective and illegal cutting of mangroves and promote other species of trees for domestic and commercial use to reduce the high dependency on the use of mangroves for construction purposes.

关键词： Aerial Photographs Satellite Images Allometric Equations Biomass Estimation Carbon Stock Mangrove Mida Creek

Regional representation of glaciers in Chandra Basin region,western Himalaya,India

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Geoscience Frontiers 2017年第4期8卷 841-850页

作者： Pratima Pandey S.Nawaz Ali AL.Ramanathan P.K.Champati ray G.Venkataraman Geosciences and Geohazards department Indian Institute of Remote Sensing Birbal Sahni Institute of Paleosciences School of Environmental Science Jawaharlal Nehru University Centre of Studies in resource Engineering Indian Institute of Technology

Hamtah and Chhota Shigri are two nearby,well monitored glaciers of western Himalaya,lying in the same climatic zone and driven by the same climatic *** this study,topographical characteristics of both the glacier have been explored to understand the role of topography in controlling the glacier ***,their topographical characteristics and possible response towards climatic variations have been compared with each other and also with that of the other glaciers in the basin to find out the suitability of these two glaciers to be considered as representative of the *** sensor and multi temporal remote sensing data have been used to carry out to fulfill the *** is found that being in the same climatic zone,the mean accumulation area ratio of Chhota Shigri is 54%and Hamtah is 11%between 1980 and *** comparison to Hamtah,Chhota Shigri glacier has a small upslope area,low compactness ratio indicating the ability of the glacier to receive direct precipitation and solar *** analysis revealed that the Chhota Shigri glacier has a closer resemblance with the other glaciers in the region than Hamtah ***,the topographical settings of Chhota Shigri glacier are suitable for recording and reflecting year-to-year climatic variations.

关键词： Himalaya Glacier Regional representation Topography remote sensing

Assessing Tree Species Dominance along an Agro Ecological Gradient in the Mau Forest Complex, Kenya

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Open Journal of Ecology 2014年第11期4卷 662-670页

作者： Mwangi James Kinyanjui Chris A. Shisanya Ondimu Ken Nyabuti Wargute Patrick Waqo Merceline Awuor Ojwala department of Geography Egerton University Njoro Kenya department of Geography Kenyatta University Nairobi Kenya department of resource surveys and remote sensing Nairobi Kenya

Species relative dominance by basal area was assessed along an agro ecological gradient in the Mau Forest Complex (MFC). Trees were recorded per species and diameter at breast height (D1.3) for size class D1.3 ≥ 10 cm in 60 quarter hectare plots distributed in 7 agro ecological zones (AEZ) namely LH1, LH2, LH3, LH4, UH0, UH1 and UH2. Basal area per species was used to calculate species relative dominance i.e. the proportion of basal area by a species to the total basal area of the AEZ. Species associations were analysed as the group of highly ranked species in each AEZ. Sorensons similarity index was used to calculate the proportion of similar species among AEZ. Analysis of variance compared basal area among AEZ and Tukey’s multiple comparison test used to identify specific AEZ with differences. Tabernaemontana stapfiana (Britten) was ranked first in LH1, UH1 and UH0 with relative dominance values of 22.66%, 22.89% and 30.73% respectively. It was however not recorded in any other AEZs. Dombeya goetzenii (K. Schum) occurred in 6 of the 7 AEZs but had moderate dominance values in each of the 6 AEZs. The sum of dominance values per species in all AEZs indicated no species mono-dominance and different species dominated at different AEZs. Co-dominance resulted in species associations like Tabernaemontana-Allophylus-Eke-bergia-Albizia in LH1, Juniperus-Dombeya-Casearia-Prunus in LH2, Acokanthera-Cussonia-Olea-Teclea in LH4 and Tabernaemontana-Syzygium-Podocarpus-Neoboutonia in UH1. Species richness was highest in UH1 and had the highest similarity indices with those of other AEZs. The UH1 had a species similarity of 67% with LH1, 63% with LH2 and 56% with LH4. However, species in the very humid zone UH0 differed with those of the drier lower highland zones (UH0 vs LH3 and vs LH4 = 31% and 37% respectively). Basal area differed significantly among AEZ ( = 3.76) showing that they differ in stocking levels. Tukeys test showed that high potential zones of LH1, LH2, UH0, UH1 d

关键词： Species Dominance Basal Area Agro Ecological Zoning

Atmospheric correction for HY-1C CZI images using neural network in western Pacific region

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Geo-Spatial Information Science 2022年第3期25卷 476-488页

作者： Jilin Men Jianqiang Liu Guangping Xia Tong Yue Ruqing Tong Liqiao Tian Kohei Arai Linyu Wang State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina Ministry of Natural resource of the People’s Republic of China National Satellite Ocean Application ServiceBeijingChina School of remote sensing and Information Engineering Wuhan UniversityWuhanChina department of Information Science Saga UniversitySagaJapan department of Urban Development Wuhan Land Containment and Reserve CenterWuhanChina

With a spatial resolution of 50 m,a revisit time of three days,and a swath of 950 km,the coastal zone imager(CZI)offers great potential in monitoring coastal zone *** atmo-spheric correction(AC)is needed to exploit the potential of quantitative ocean color ***,due to the band setting of CZI,the AC over coastal waters in the western Pacific region with complex optical properties cannot be realized *** research introduces a novel neural network(NN)AC algorithm for CZI data over coastal *** 100,000 match-ups of HY-1 C CZI-observed reflectance at the top-of-atmosphere and Operational Land Imager(OLI)-retrieved high-quality remote sensing reflectance(Rrs)at the CZI bands are built to train the NN *** reflectance data are obtained from the standard AC algorithm in the *** indicate that the distributions of the CZI retrieved Rrs were consistent with the quasi-synchronous OLI data,but the spatial information from the CZI is more ***,the accuracy of the CZI data for AC is evaluated using the multi-source in-situ *** further show that the NN-AC can successfully retrieve Rrs for CZI and the coefficients of determination in the blue,green,red,and near-infrared bands were 0.70,0.77,0.76,and 0.67,*** NN algorithm does not depend on shortwave-infrared bands and runs very fast once properly trained.

关键词： HaiYang-1C coastal zone imager(HY-1C CZI) atmospheric correction neural network coastal water remote sensing

Ionic composition of submicron particles(PM_(1.0)) during the long-lasting haze period in January 2013 in Wuhan, central China

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Journal of Environmental Sciences 2014年第4期26卷 810-817页

作者： Hairong Cheng Wei Gong Zuwu Wang Fan Zhang Xinming Wang Xiaopu Lv Jia Liu Xiaoxin Fu Gan Zhang department of Environmental Engineering School of Resource and Environmental Sciences Wuhan University State Key Laboratory for Information Engineering in Surveying Mapping and Remote Sensing Wuhan University State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences

In January 2013, a long-lasting severe haze episode occurred in Northern and Central China; at its maximum, it covered a land area of approximately 1.4 million km2. In Wuhan, the largest city in Central China, this event was the most severe haze episode in the 21st century. Aerosol samples of submicron particles （PMI.o） were collected during the long-lasting haze episode at an urban site and a suburban site in Wuhan to investigate the ion characteristics of PMi.0 in this area. The mass concentrations of PM1.0 and its water-soluble inorganic ions （WSIIs） were almost at the same levels at two sites, which indicates that PM1.0 pollution occurs on a regional scale in Wuhao. WSIIs （Na^＋, NH4^＋, K^＋, Mg^2＋, Ca^2＋, Cl^-, NO3 and SO2-） were the dominant chemical species and constituted up to 48.4% and 47.4% of PM1.0 at WD and TH, respectively. The concentrations of PM1.0 and WSIIs on haze days were approximately two times higher than on normal days. The ion balance calculations indicate that the particles were more acidic on haze days than on normal days. The results of the back trajectory analysis imply that the high concentrations of PM1.0 and its water-soluble inorganic ions may be caused by stagnant weather conditions in Wuhan.

关键词： PM1.0 water-soluble inorganic ions haze source back trajectory

Text GCN-SW-KNN:a novel collaborative training multi-label classification method for WMS application themes by considering geographic semantics

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Big Earth Data 2021年第1期5卷 66-89页

作者： Zhengyang Wei Zhipeng Gui Min Zhang Zelong Yang Yuao Mei Huayi Wu Hongbo Liu Jing Yu School of remote sensing and Information Engineering Wuhan UniversityWuhanChina State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina Collaborative Innovation Center of Geospatial Technology Wuhan UniversityWuhanChina Information Technology department Chongqing Geomatics and Remote Sensing CenterChongqingChina

Without explicit description of map application themes,it is difficult for users to discover desired map resources from massive online Web Map Services(WMS).However,metadata-based map application theme extraction is a challenging multi-label text classification task due to limited training samples,mixed vocabularies,variable length and content arbitrariness of text *** this paper,we propose a novel multi-label text classification method,Text GCN-SW-KNN,based on geographic semantics and collaborative training to improve classifica-tion *** semi-supervised collaborative training adopts two base models,i.e.a modified Text Graph Convolutional Network(Text GCN)by utilizing Semantic Web,named Text GCN-SW,and widely-used Multi-Label K-Nearest Neighbor(ML-KNN).Text GCN-SW is improved from Text GCN by adjusting the adjacency matrix of the heterogeneous word document graph with the shortest semantic distances between themes and words in metadata *** distances are calculated with the Semantic Web of Earth and Environmental Terminology(SWEET)and WordNet *** on both the WMS and layer metadata show that the proposed methods can achieve higher F1-score and accuracy than state-of-the-art baselines,and demonstrate better stability in repeating experiments and robustness to less training *** GCN-SW-KNN can be extended to other multi-label text classification scenario for better supporting metadata enhancement and geospatial resource discovery in Earth Science domain.

关键词： Web map service multi-label text classification semantic distance text graph convolutional network collaborative training MLKNN application theme extraction