This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) ...This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) method and model method, incorporating the application experience of American scholars in the light of the state of our country. Firstly, the author proposes theoretical basis for population estimation by remote sensing, on the basis of analysing and evaluating the history and state quo of application of methods of population estimation by remote sensing. Secondly, two original types of mathematical models of population estimation are developed on the basis of remote sensing data, taking Tianjin City as an example. By both of the mathematical models the regional population may be estimated from remote sensing variable values with high accuracy. The number of the independent variables in the latter model is somewhat smaller and the collection of remote sensing data is somewhat easier, but the deviation is a little larger. Finally, some viewpoints on the principled problems about the practical application of remote sensing to population estimation are put forward.展开更多
The permafrost of Mohe County and its suburbs in the Daxing′an Mountains has been influenced by the urbanization.Remote sensing,GIS technology and numerical simulation was used to study the temperature variations of ...The permafrost of Mohe County and its suburbs in the Daxing′an Mountains has been influenced by the urbanization.Remote sensing,GIS technology and numerical simulation was used to study the temperature variations of permafrost with the changes in surface vegetation that cover Mohe County and suburban areas,and the law of permafrost degradation on the study area was analyzed.The research results show that the urban area of the study area increased 114.42%from 2000 to 2016,and the urbanization process is continuing to accelerate.The Normalized Difference Vegetation Index map of 2017 in Mohe County and its suburbs was studied and the maximum proportion of vegetation coverage was different in the four seasons.The numerical calculation model results show that the permafrost temperature change in the study area cyclically fluctuates in a cosine form.The annual variation curve of permafrost temperature gradually decreased and its accompanying phase lag increased with depth.The annual temperature change value with the different depths of the town was greater than the natural ground.The maximum permafrost thawing depths of the town and natural ground were 4.2 m and 2.82 m in 50 a,and the degradation rates of the two permafrost are,respectively,0.88 cm/a and 0.46 cm/a.These results show that urbanization has accelerated the degradation of permafrost.展开更多
Objective Nowadays, high-resolution remote sensing technology has brought new changes to surveys of earthquakes, and the quantitative study of seismic faults based on this technology has become a trend in the world(Ba...Objective Nowadays, high-resolution remote sensing technology has brought new changes to surveys of earthquakes, and the quantitative study of seismic faults based on this technology has become a trend in the world(Barzegari et al., 2017). An Mw 7.2 earthquake occurred in Yutian of Xinjiang on the western end of the Altyn Tagh fault on March 21 st, 2008. It is difficult to access this depopulated zone because of the high altitude and only 1–2 months of snowmelt. This study utilized high-resolution展开更多
Tibet Plateau is Known as "the Roof of the World" with the area of 1,220,000km^2, which is about 1/8 land area of China. Because of the high elevation, cold climate and it caused difficulties in regional eco...Tibet Plateau is Known as "the Roof of the World" with the area of 1,220,000km^2, which is about 1/8 land area of China. Because of the high elevation, cold climate and it caused difficulties in regional economic planning and land resources management. Since 1985, the land use investigation in Tibet has been carried out, in which the basic data and thematic maps must be obtained and completed at county and township levels, in order to meet the needs of local administrations. In the investigation, remote sensing technology was comprehensively adopted. At present, the investigation in county level had been completed and the compilation is going to be carried out. Due to paying a great attention to studying on a series of key technical problems, the systematic methods of using remote sensing technology in the plateau land use investigation were formed and successfully put into application.展开更多
The Remote Radio Head (RRH) over Fiber system is a new distributed network coverage mode.It processes the baseband parts concentratively by separating the baseband and Radio Frequency (RF).It moves the RF modules usin...The Remote Radio Head (RRH) over Fiber system is a new distributed network coverage mode.It processes the baseband parts concentratively by separating the baseband and Radio Frequency (RF).It moves the RF modules using fibers from the Base Stations (BSs) to the remote RF units.These RF modules are placed on the stations to be covered.This solution saves many equipment rooms required by conventional solutions.Meanwhile,it supports RRH over a large number of fibers through high-capacity macro BSs to realize the conversion between capacity and coverage.In addition,the RRH system also supports the coverage in other situations,such as high-speed railways and ultra-long distance.It is one of the most widely used technologies in the 3G network.展开更多
Disaster warning,disaster estimation and relief depend more and more on the application of space remote sensing technologies,such as those used for optic-camera,hyperspectrum,infrared,SAR,seismo-electromagnet and grav...Disaster warning,disaster estimation and relief depend more and more on the application of space remote sensing technologies,such as those used for optic-camera,hyperspectrum,infrared,SAR,seismo-electromagnet and gravitation measurement.On May 12,2008,a magnitude of 8.展开更多
The environmental conditions in China are still very serious. In the years to come, the mission for environmental treatment and protection, supervision,
Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real...Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real-world monitoring,the process will use RTK-GNSS positional perception technology,by projecting the left side of the earth from Gauss-Krueger projection method,and then carry out the Cartesian conversion based on the characteristics of drawing;steering control system is the core of the electric drive unmanned module,on the basis of the analysis of the composition of the steering system of unmanned engineering vehicles,the steering system key components such as direction,torque sensor,drive motor and other models are established,the joint simulation model of unmanned engineering vehicles is established,the steering controller is designed using the PID method,the simulation results show that the control method can meet the construction path demand for automatic steering.The path planning will first formulate the construction area with preset values and realize the steering angle correction during driving by PID algorithm,and never realize the construction-based path planning,and the results show that the method can control the straight path within the error of 10 cm and the curve error within 20 cm.With the collaboration of various modules,the automatic construction simulation results of this robot show that the design path and control method is effective.展开更多
Establishing the remote sensing algorithm of retrieving the absorption coefficient of seawater petroleum substances is an efficient way to improve the accuracy of retrieving a seawater petroleum concentration using a ...Establishing the remote sensing algorithm of retrieving the absorption coefficient of seawater petroleum substances is an efficient way to improve the accuracy of retrieving a seawater petroleum concentration using a remote sensing technology. A remote sensing reflectance is a basic physical parameter in water color remote sensing. Apply it to directly retrieve the absorption coefficient of seawater petroleum substances is of potential advantage. The absorption coefficient of waters containing petroleum [ACWCP, a_o(λ)], consists of the absorption coefficient of pure water [ACPW, a_w(λ)], plankton [ACP, a_(ph)(λ)], colored scraps [ACCS, a_(d,g)(λ)], and petroleum substance [ACPS, a_(oil)(λ)]. Among those, ACCS consists of the absorption coefficient of nonalgal particle [ACNP, a_d(λ)] and colored dissolved organic matter [ACCDOM, a_g(λ)]. For waters containing petroleum, the retrieved ACCS using the existing method is a combination absorption coefficient of ACNP,ACCDOM and ACPA [CAC, a_(d,g,oil)(λ)]. Therefore, the principle question is how to extract ACPS from CAC.Through the analysis of the three proportion tests conducted between the year of 2013 and 2015 and the corresponding remote sensing data, an algorithm of retrieving the absorption coefficient of petroleum substances is proposed based on remote sensing reflectance. First of all, ACPS and CAC are retrieved from the reflectance using the quasi-analytical algorithm(QAA), with some parameter modified. Secondly, given the fact that the backscatter coefficient [BC, b_(bp)(555)] of total particles at 555 nm can be obtained completely from the reflectance, the relation between BC and ACNP in petroleum contaminated water can be established. As a result, ACNP can be calculated. Then, combining the remote sensing retrieving algorithm of a_g(440), the method of achieving the spectral slope of the absorption coefficient can be established, from which ACCDOM,can be calculated. Finally, ACPS can be computed as the residual. The accuracy of ACPS based on this algorithm is 86% compared with the in situ measurements.展开更多
Mount Lokon is an active mountain near residential areas such as cities Tomohon, Tondano, and Manado. Along with the increasing population and population development around Mount Lokon, vegetation is decreasing due to...Mount Lokon is an active mountain near residential areas such as cities Tomohon, Tondano, and Manado. Along with the increasing population and population development around Mount Lokon, vegetation is decreasing due to converting land from grassland to land use for human activities. Using Landsat 8 OLI/TIRS images, this study was conducted to analyze the surface temperature and vegetation index dynamics around Mount Lokon, including the residential areas. Found that an increase in mean temperature occurred, and the peak increased dramatically in 2018 with temperatures > 26˚C. This result, of course, correlates with the decreasing vegetation area. However, the decline occurred in 2020 due to decreased human activities and land clearing for new settlements caused by activity restrictions which were the effects of the COVID-19 pandemic. Reforestation efforts must be made to increase the vege<span style="font-family:Verdana;">tation around Mount Lokon, including residential areas. The avera</span><span style="font-family:Verdana;">ge surface temperature can be controlled, and living creatures can be given comfort to living things around them even after the pandemic and human activities return to normal.</span>展开更多
Due to differences in environmental factors,the phenology of the same crop is different every year,causing divergent performances of the classifier built by spectral or time-series features Here,we proposed a random f...Due to differences in environmental factors,the phenology of the same crop is different every year,causing divergent performances of the classifier built by spectral or time-series features Here,we proposed a random forest classifier(RFC)based on an asymmetric double S curve model fitted by accumulated temperature(AT)and Vegetation Index(VI),which can be applied in different years without ground samples.We built AT and VI time series from Moderate Resolution Imaging Spectroradiometer 8-day composites of land surface temperatures and Sentinel-2 and Landsat-8,respectively.The RFC was trained by characteristics from the asymmetric double S curve.We prepared RFC by ground samples of 2018 and 2019 and then mapped crops of the same region in 2017.Results indicated that,compared with diverse VI-AT series,the overall accuracy based on universal normalized vegetation index(UNVI)was the best of all(2017:F1=0.91,2018:F1=0.92,2019:F1=0.91)and better than that based on the UNVI-TIME series(2017:F1=0.84,2018:F1=0.81,2019:F1=0.88).It proved that the classification features from the VI-AT series have smaller intra-class differences in 2017,2018,and 2019.展开更多
The paper gives an overview of the current status of education in geoinformatics in China.First,the paper provides a brief introduction to the history of geoinformatics education in China and a general review of the s...The paper gives an overview of the current status of education in geoinformatics in China.First,the paper provides a brief introduction to the history of geoinformatics education in China and a general review of the scientific and technological development.It then presents how the development affects the education and training in China.In the paper,universities and institutes in China that can award academic degrees related to geoinformatics are summarized,and undergraduate majors are briefly introduced.Next,the paper reports the work having been done by the national expert group on Surveying and Mapping,including the revision of discipline catalog and guide for graduate education and requirements.A list of typical curricula in geoinformatics education is suggested.Activities on promoting the graduate student exchange platform are presented.Finally,a case study of geoinformatics education in Wuhan University is discussed.展开更多
文摘This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) method and model method, incorporating the application experience of American scholars in the light of the state of our country. Firstly, the author proposes theoretical basis for population estimation by remote sensing, on the basis of analysing and evaluating the history and state quo of application of methods of population estimation by remote sensing. Secondly, two original types of mathematical models of population estimation are developed on the basis of remote sensing data, taking Tianjin City as an example. By both of the mathematical models the regional population may be estimated from remote sensing variable values with high accuracy. The number of the independent variables in the latter model is somewhat smaller and the collection of remote sensing data is somewhat easier, but the deviation is a little larger. Finally, some viewpoints on the principled problems about the practical application of remote sensing to population estimation are put forward.
基金Nation Natural Science Foundation of China under Grant No.41071049Project of the State Key Laboratory Frozen Soil Engineering of CAS under Grant No.SKLFSE201802Project of 2017 Harbin Applied Technology Research and Development under Grant No.2017RAXXJ031。
文摘The permafrost of Mohe County and its suburbs in the Daxing′an Mountains has been influenced by the urbanization.Remote sensing,GIS technology and numerical simulation was used to study the temperature variations of permafrost with the changes in surface vegetation that cover Mohe County and suburban areas,and the law of permafrost degradation on the study area was analyzed.The research results show that the urban area of the study area increased 114.42%from 2000 to 2016,and the urbanization process is continuing to accelerate.The Normalized Difference Vegetation Index map of 2017 in Mohe County and its suburbs was studied and the maximum proportion of vegetation coverage was different in the four seasons.The numerical calculation model results show that the permafrost temperature change in the study area cyclically fluctuates in a cosine form.The annual variation curve of permafrost temperature gradually decreased and its accompanying phase lag increased with depth.The annual temperature change value with the different depths of the town was greater than the natural ground.The maximum permafrost thawing depths of the town and natural ground were 4.2 m and 2.82 m in 50 a,and the degradation rates of the two permafrost are,respectively,0.88 cm/a and 0.46 cm/a.These results show that urbanization has accelerated the degradation of permafrost.
基金supported by the National Natural Science Foundation of China (grants No. 41461164002 and 41631073)
文摘Objective Nowadays, high-resolution remote sensing technology has brought new changes to surveys of earthquakes, and the quantitative study of seismic faults based on this technology has become a trend in the world(Barzegari et al., 2017). An Mw 7.2 earthquake occurred in Yutian of Xinjiang on the western end of the Altyn Tagh fault on March 21 st, 2008. It is difficult to access this depopulated zone because of the high altitude and only 1–2 months of snowmelt. This study utilized high-resolution
文摘Tibet Plateau is Known as "the Roof of the World" with the area of 1,220,000km^2, which is about 1/8 land area of China. Because of the high elevation, cold climate and it caused difficulties in regional economic planning and land resources management. Since 1985, the land use investigation in Tibet has been carried out, in which the basic data and thematic maps must be obtained and completed at county and township levels, in order to meet the needs of local administrations. In the investigation, remote sensing technology was comprehensively adopted. At present, the investigation in county level had been completed and the compilation is going to be carried out. Due to paying a great attention to studying on a series of key technical problems, the systematic methods of using remote sensing technology in the plateau land use investigation were formed and successfully put into application.
基金supported by the National Natural Science Foundation of China under Grant No.60877052
文摘The Remote Radio Head (RRH) over Fiber system is a new distributed network coverage mode.It processes the baseband parts concentratively by separating the baseband and Radio Frequency (RF).It moves the RF modules using fibers from the Base Stations (BSs) to the remote RF units.These RF modules are placed on the stations to be covered.This solution saves many equipment rooms required by conventional solutions.Meanwhile,it supports RRH over a large number of fibers through high-capacity macro BSs to realize the conversion between capacity and coverage.In addition,the RRH system also supports the coverage in other situations,such as high-speed railways and ultra-long distance.It is one of the most widely used technologies in the 3G network.
文摘Disaster warning,disaster estimation and relief depend more and more on the application of space remote sensing technologies,such as those used for optic-camera,hyperspectrum,infrared,SAR,seismo-electromagnet and gravitation measurement.On May 12,2008,a magnitude of 8.
文摘The environmental conditions in China are still very serious. In the years to come, the mission for environmental treatment and protection, supervision,
文摘Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real-world monitoring,the process will use RTK-GNSS positional perception technology,by projecting the left side of the earth from Gauss-Krueger projection method,and then carry out the Cartesian conversion based on the characteristics of drawing;steering control system is the core of the electric drive unmanned module,on the basis of the analysis of the composition of the steering system of unmanned engineering vehicles,the steering system key components such as direction,torque sensor,drive motor and other models are established,the joint simulation model of unmanned engineering vehicles is established,the steering controller is designed using the PID method,the simulation results show that the control method can meet the construction path demand for automatic steering.The path planning will first formulate the construction area with preset values and realize the steering angle correction during driving by PID algorithm,and never realize the construction-based path planning,and the results show that the method can control the straight path within the error of 10 cm and the curve error within 20 cm.With the collaboration of various modules,the automatic construction simulation results of this robot show that the design path and control method is effective.
基金The National Natural Science Foundation of China under contract No.41271364the Key Projects in the National Science and Technology Pillar Program of China under contract No.2012BAH32B01-4the Program for Scientific Research Start-up Funds of Guangdong Ocean University under contract No.E16187
文摘Establishing the remote sensing algorithm of retrieving the absorption coefficient of seawater petroleum substances is an efficient way to improve the accuracy of retrieving a seawater petroleum concentration using a remote sensing technology. A remote sensing reflectance is a basic physical parameter in water color remote sensing. Apply it to directly retrieve the absorption coefficient of seawater petroleum substances is of potential advantage. The absorption coefficient of waters containing petroleum [ACWCP, a_o(λ)], consists of the absorption coefficient of pure water [ACPW, a_w(λ)], plankton [ACP, a_(ph)(λ)], colored scraps [ACCS, a_(d,g)(λ)], and petroleum substance [ACPS, a_(oil)(λ)]. Among those, ACCS consists of the absorption coefficient of nonalgal particle [ACNP, a_d(λ)] and colored dissolved organic matter [ACCDOM, a_g(λ)]. For waters containing petroleum, the retrieved ACCS using the existing method is a combination absorption coefficient of ACNP,ACCDOM and ACPA [CAC, a_(d,g,oil)(λ)]. Therefore, the principle question is how to extract ACPS from CAC.Through the analysis of the three proportion tests conducted between the year of 2013 and 2015 and the corresponding remote sensing data, an algorithm of retrieving the absorption coefficient of petroleum substances is proposed based on remote sensing reflectance. First of all, ACPS and CAC are retrieved from the reflectance using the quasi-analytical algorithm(QAA), with some parameter modified. Secondly, given the fact that the backscatter coefficient [BC, b_(bp)(555)] of total particles at 555 nm can be obtained completely from the reflectance, the relation between BC and ACNP in petroleum contaminated water can be established. As a result, ACNP can be calculated. Then, combining the remote sensing retrieving algorithm of a_g(440), the method of achieving the spectral slope of the absorption coefficient can be established, from which ACCDOM,can be calculated. Finally, ACPS can be computed as the residual. The accuracy of ACPS based on this algorithm is 86% compared with the in situ measurements.
文摘Mount Lokon is an active mountain near residential areas such as cities Tomohon, Tondano, and Manado. Along with the increasing population and population development around Mount Lokon, vegetation is decreasing due to converting land from grassland to land use for human activities. Using Landsat 8 OLI/TIRS images, this study was conducted to analyze the surface temperature and vegetation index dynamics around Mount Lokon, including the residential areas. Found that an increase in mean temperature occurred, and the peak increased dramatically in 2018 with temperatures > 26˚C. This result, of course, correlates with the decreasing vegetation area. However, the decline occurred in 2020 due to decreased human activities and land clearing for new settlements caused by activity restrictions which were the effects of the COVID-19 pandemic. Reforestation efforts must be made to increase the vege<span style="font-family:Verdana;">tation around Mount Lokon, including residential areas. The avera</span><span style="font-family:Verdana;">ge surface temperature can be controlled, and living creatures can be given comfort to living things around them even after the pandemic and human activities return to normal.</span>
基金partially supported by the National Natural Science Foundation of China[gran numbers 41830108 and 41971321)Key Research Program of Frontier Sciences,CAS[grant number ZDBS-LY-DQC012]+2 种基金Major Science and Technology Projects of XPCC[grant number 2018AA00402]Innovation Team of XPCC’s Key Area[grant number 2018CB004]Changping Huang was supported by Youth Innovation Promotion Association,CAS(grant number Y2021047).
文摘Due to differences in environmental factors,the phenology of the same crop is different every year,causing divergent performances of the classifier built by spectral or time-series features Here,we proposed a random forest classifier(RFC)based on an asymmetric double S curve model fitted by accumulated temperature(AT)and Vegetation Index(VI),which can be applied in different years without ground samples.We built AT and VI time series from Moderate Resolution Imaging Spectroradiometer 8-day composites of land surface temperatures and Sentinel-2 and Landsat-8,respectively.The RFC was trained by characteristics from the asymmetric double S curve.We prepared RFC by ground samples of 2018 and 2019 and then mapped crops of the same region in 2017.Results indicated that,compared with diverse VI-AT series,the overall accuracy based on universal normalized vegetation index(UNVI)was the best of all(2017:F1=0.91,2018:F1=0.92,2019:F1=0.91)and better than that based on the UNVI-TIME series(2017:F1=0.84,2018:F1=0.81,2019:F1=0.88).It proved that the classification features from the VI-AT series have smaller intra-class differences in 2017,2018,and 2019.
基金The work is supported by the National Basic Research Program of China(973 Program)(grant number 2011CB707105)the National Natural Science Foundation of China(grant number 41271397)the Program for New Century Excellent Talents in University(grant number NCET-13-0435).
文摘The paper gives an overview of the current status of education in geoinformatics in China.First,the paper provides a brief introduction to the history of geoinformatics education in China and a general review of the scientific and technological development.It then presents how the development affects the education and training in China.In the paper,universities and institutes in China that can award academic degrees related to geoinformatics are summarized,and undergraduate majors are briefly introduced.Next,the paper reports the work having been done by the national expert group on Surveying and Mapping,including the revision of discipline catalog and guide for graduate education and requirements.A list of typical curricula in geoinformatics education is suggested.Activities on promoting the graduate student exchange platform are presented.Finally,a case study of geoinformatics education in Wuhan University is discussed.