The Law of Soil and Water Conservation entitles the administrations of water resources at various level to monitor ecological environment and to proclaim status of soil erosion periodically.Monitoring units of soil an...The Law of Soil and Water Conservation entitles the administrations of water resources at various level to monitor ecological environment and to proclaim status of soil erosion periodically.Monitoring units of soil and water conservation approved by local governments are obliged to undertake this work.How to develop a monitoring program needs an overall and long-term concept.Particularity and objectives of ecological environment monitoring was discussed. Monitoring at provincial level may be divided into two levels:province-wide and at project level. Those indicators meaningful,sensitive to any disturbances,and simple to measure may be selected to test status of ecosystem stability and health.It makes sense to have an integrated sampling design,to set up permanent observation plots and to collect data, so that to have a relative timely,accurate understanding of ecosystems in the province.A program regarding sampling design,field methods, data analysis,documentation and implementation was detailed.展开更多
Environment and disaster monitoring and forecasting small satellite constellation A and B satellites(HJ-1-A,B) are called "environment and disaster reduction satellites A and B" for short.The constellation a...Environment and disaster monitoring and forecasting small satellite constellation A and B satellites(HJ-1-A,B) are called "environment and disaster reduction satellites A and B" for short.The constellation adopts a 10:30LT sun-synchronous circular orbit,with orbit altitude of 649km.HJ1-A and HJ-1-B are distributed with a phase difference of 180° in the same orbital plane,so as to enhance the time resolution of earth observation.The satellites have orbit maintenance capability,the lifetime is 3 years.Both satellites adopt CAST968 platforms.Two wide-coverage multispectral CCD cameras with resolution 30m and width 700km,a super-spectral imager with resolution 100m and width 50km as well as a data transmission subsystem of 120Mbit/s are deployed on HJ-1-A,which also carries Ka communication testing equipment of Thailand.HJ-1-B has two wide-coverage multispectral CCD cameras(the same as satellite A),one infrared camera with resolution 150m and width 720km and a data transmission subsystem of 60Mbit/s.The coverage period of the wide-coverage multispectral CCD camera is 48 hours.The revisit period of super-spectral imager is 96 hours and the coverage period ofinfrared camera is 96 hours.展开更多
Environment and Disasters Monitoring Microsatellite Constellation with high spatial resolution,high temporal resolution and high spectral resolution characteristics was put forward by China.HJ-1B satellite,one of the ...Environment and Disasters Monitoring Microsatellite Constellation with high spatial resolution,high temporal resolution and high spectral resolution characteristics was put forward by China.HJ-1B satellite,one of the first two small optical satellites,had a CCD camera and an infrared camera,which would provide an important new data source for snow monitoring.In the present paper,through analyzing the sensor and data characteristics of HJ-1B,we proposed a new infrared normalized difference snow index(INDSI) referring to the traditional normalized difference snow index(NDSI).The accuracy of these two automatic snow recognition methods was estimated based on a supervised classification method.The accuracy of the traditional NDSI method was 97.761 9% while that of the new INDSI method was 98.617 1%.展开更多
During the past two years,space environment has achieved great development in space environment monitoring,model research,system developing and space environment service in China.In this paper,we mainly introduce spac...During the past two years,space environment has achieved great development in space environment monitoring,model research,system developing and space environment service in China.In this paper,we mainly introduce space environment safety support for Shenzhou-7 manned spacecraft,two typical space environment operation platforms,and the advance of Re-locatable Atmospheric Observatory(RAO).At the last part of this paper,the Sub-committee on Space Environment(SSE) which was set up in 2009 under the Technical Committee on Space Technology and Operation of Standardization Administration of China is briefly introduced.展开更多
随着自动驾驶技术的快速发展,4D毫米波雷达因其全天候适应性和抗干扰能力,成为同步定位与地图构建(Simultaneous Localization and Mapping,SLAM)的关键传感器。然而在隧道等封闭环境中,多径效应引发的虚警点云严重影响了雷达SLAM系统...随着自动驾驶技术的快速发展,4D毫米波雷达因其全天候适应性和抗干扰能力,成为同步定位与地图构建(Simultaneous Localization and Mapping,SLAM)的关键传感器。然而在隧道等封闭环境中,多径效应引发的虚警点云严重影响了雷达SLAM系统的定位精度与建图效果。针对这一问题,本文基于对隧道中的毫米波雷达点云数据特性和散射角特征的规律分析提出了一种全新的滑窗动态滤波算法。该方法结合了点云的空间统计特性与邻域密度检测方法剔除离群噪声点云,利用雷达点云粗配准获得先验估计位姿,结合雷达点云俯仰向和方位向的三维散射角特征,实现对真实目标点云数据的区分和聚类。随后使用随机采样一致性算法(Random Sample Consensus,RANSAC)拟合隧道墙壁平面并构建隧道墙面模型。通过引入动态滑窗更新策略,利用拟合的隧道墙面模型与先验估计位姿实时更新当前姿态节点到墙面边界距离阈值,使用距离阈值进一步消除隧道空间以外的虚警点云和噪声点云,并在因子图优化框架下完成全局位姿修正与局部地图更新。本研究在真实的隧道环境中采集多个不同场景的数据进行实验验证,实验结果证明本研究提出的方法在有效降低虚警点云干扰的同时,显著提高了定位精度和建图质量,且能在复杂环境中保持较高的稳定性。本研究为提高4D毫米波雷达SLAM在封闭环境中的鲁棒性提供了新的技术思路和实现路径。展开更多
为了有效地实时监测肉鸡生产过程中的环境因子,提高肉鸡健康养殖水平,本文将传感器技术与窄带物联网(Narrow Band Internet of Things,NB-IoT)技术结合,设计并实现一种肉鸡养殖环境监测系统,使用无线传感器实时监测肉鸡养殖环境中的温...为了有效地实时监测肉鸡生产过程中的环境因子,提高肉鸡健康养殖水平,本文将传感器技术与窄带物联网(Narrow Band Internet of Things,NB-IoT)技术结合,设计并实现一种肉鸡养殖环境监测系统,使用无线传感器实时监测肉鸡养殖环境中的温度、湿度、光照、NH 3等环境因子,采用B/S(浏览器/服务器)模式,运用NB-IoT技术将信息传输至云端服务器。结果表明:通过该方法可实现环境数据查询、绘制环境变化曲线、远程向终端设备下发控制命令等功能。该系统具有低功耗、低成本的优势,操作简便、性能稳定,为养殖户的决策分析提供了有效信息和科学依据。展开更多
基金the Scientific Research Foundation for the Returned Overseas Chinese ScholarsState Education Ministry"Response ofForest Regeneration in Alpine Region to Global Climate Change"( 2 0 0 2 -2 0 0 4) Shaanxi Provincial Foreign Expert Bu-reau"Trial on Vegetation Rehabilitation in Degraded Mountain Ecosystem"( 2 0 0 2 -2 0 0 3 )
文摘The Law of Soil and Water Conservation entitles the administrations of water resources at various level to monitor ecological environment and to proclaim status of soil erosion periodically.Monitoring units of soil and water conservation approved by local governments are obliged to undertake this work.How to develop a monitoring program needs an overall and long-term concept.Particularity and objectives of ecological environment monitoring was discussed. Monitoring at provincial level may be divided into two levels:province-wide and at project level. Those indicators meaningful,sensitive to any disturbances,and simple to measure may be selected to test status of ecosystem stability and health.It makes sense to have an integrated sampling design,to set up permanent observation plots and to collect data, so that to have a relative timely,accurate understanding of ecosystems in the province.A program regarding sampling design,field methods, data analysis,documentation and implementation was detailed.
文摘Environment and disaster monitoring and forecasting small satellite constellation A and B satellites(HJ-1-A,B) are called "environment and disaster reduction satellites A and B" for short.The constellation adopts a 10:30LT sun-synchronous circular orbit,with orbit altitude of 649km.HJ1-A and HJ-1-B are distributed with a phase difference of 180° in the same orbital plane,so as to enhance the time resolution of earth observation.The satellites have orbit maintenance capability,the lifetime is 3 years.Both satellites adopt CAST968 platforms.Two wide-coverage multispectral CCD cameras with resolution 30m and width 700km,a super-spectral imager with resolution 100m and width 50km as well as a data transmission subsystem of 120Mbit/s are deployed on HJ-1-A,which also carries Ka communication testing equipment of Thailand.HJ-1-B has two wide-coverage multispectral CCD cameras(the same as satellite A),one infrared camera with resolution 150m and width 720km and a data transmission subsystem of 60Mbit/s.The coverage period of the wide-coverage multispectral CCD camera is 48 hours.The revisit period of super-spectral imager is 96 hours and the coverage period ofinfrared camera is 96 hours.
基金HJ-1 Satellite data Application Research Project(2008A01A1300)National High Technology Research and Development Program(2009AA12Z101)Key Project of Knowledge Innovation Program of Chinese Academy of Sciences(KZCX2-YW-Q03-07)
文摘Environment and Disasters Monitoring Microsatellite Constellation with high spatial resolution,high temporal resolution and high spectral resolution characteristics was put forward by China.HJ-1B satellite,one of the first two small optical satellites,had a CCD camera and an infrared camera,which would provide an important new data source for snow monitoring.In the present paper,through analyzing the sensor and data characteristics of HJ-1B,we proposed a new infrared normalized difference snow index(INDSI) referring to the traditional normalized difference snow index(NDSI).The accuracy of these two automatic snow recognition methods was estimated based on a supervised classification method.The accuracy of the traditional NDSI method was 97.761 9% while that of the new INDSI method was 98.617 1%.
文摘During the past two years,space environment has achieved great development in space environment monitoring,model research,system developing and space environment service in China.In this paper,we mainly introduce space environment safety support for Shenzhou-7 manned spacecraft,two typical space environment operation platforms,and the advance of Re-locatable Atmospheric Observatory(RAO).At the last part of this paper,the Sub-committee on Space Environment(SSE) which was set up in 2009 under the Technical Committee on Space Technology and Operation of Standardization Administration of China is briefly introduced.
文摘为了有效地实时监测肉鸡生产过程中的环境因子,提高肉鸡健康养殖水平,本文将传感器技术与窄带物联网(Narrow Band Internet of Things,NB-IoT)技术结合,设计并实现一种肉鸡养殖环境监测系统,使用无线传感器实时监测肉鸡养殖环境中的温度、湿度、光照、NH 3等环境因子,采用B/S(浏览器/服务器)模式,运用NB-IoT技术将信息传输至云端服务器。结果表明:通过该方法可实现环境数据查询、绘制环境变化曲线、远程向终端设备下发控制命令等功能。该系统具有低功耗、低成本的优势,操作简便、性能稳定,为养殖户的决策分析提供了有效信息和科学依据。
