共查询到20条相似文献,搜索用时 15 毫秒
1.
基于植被指数和地表温度特征空间的农业干旱监测模型研究综述 总被引:2,自引:0,他引:2
遥感技术是监测区域农业旱情时空变化的主要手段,其反演的植被指数(NDVI)和地表温度(Ts)两个参数可以通过表征绿色植被对干旱胁迫生境的反应揭示土壤水分信息,反映作物受旱状况,但两者单独使用时均存在局限性。而基于植被指数和地表温度的二维特征空间综合了两个参数特有的生理生态意义,不仅可以指示作物受旱时的水热胁迫环境,同时揭示了作物在这种胁迫环境下表现出的症状,可有效提高农业干旱监测的精度和效率。本文在较为详细地阐述植被指数-地表温度特征空间评估农业旱情的原理基础上,综述了这方面有代表性的4个干旱监测模型,初步分析了影响这类模型特征空间的部分非土壤水分因子,并对它们在应用中的优缺点做了评述和总结,为今后此领域研究中需要关注的问题做了展望。 相似文献
2.
A. M. Borovikov 《地理信息系统科学与遥感》2013,50(2):128-145
The author tries to demonstrate the accuracy and reliability of remote sensing in geology. Separate procedures, stages and conditions of image processing are discussed. According to the author, by minimizing errors and interference, understanding the mechanism of generalization, improving identification techniques, and recognizing various direct and indirect indicators, this method can be made highly universal and promising for the earth sciences. Translated from: Kosmicheskiye issledovaniya prirodnykh kompleksov Sibiri i Dal'nego Vostoka, Novosibirsk, 1983, pp. 83-100. 相似文献
3.
A final paper on water-level monitoring from space outlines principles for the use of space imagery in interpretation of short-term changes in the position of shorelines and coastal water levels resulting from storm surges and strong offshore winds. Over 100 images of various types, seasons, and storm-surge conditions, carefully referenced with field data on slope, vegetation cover, water level, and wind direction, were used to determine “maximal” and “minimal” positions of the Caspian shoreline for the period 1973-1983. This information is useful in understanding the seasonal regime of water-level fluctuations and anticipating flooding associated with winds of a given velocity. Translated from: Izvestlya vysshikh uchebnykh zavedenly, geodeziya i aerofotos'yemka, 1986, No. 4, pp. 93-97. 相似文献
4.
5.
针对三维空间和高程未知的二维空间之间的七参数的求解问题,提出了一种新的高程趋近法,以真实数据和模拟数据证明了其可行性。 相似文献
6.
V. I. Kravtsova 《地理信息系统科学与遥感》2013,50(3):169-178
This paper outlines some principles believed necessary for the establishment of integrated collections of remote sensing imagery, including, at the national level, a unified state image repository for the USSR. A multi-criterion classification of imagery is introduced, which provides a framework for structuring such a repository, and a number of measures for evaluating the utility of imagery within it are described. One of the latter is “geographic” resolution (levels of image detail), which provides a relatively straightforward indication of the type of geographic information embedded within particular types of remote sensing imagery. Translated by Jay K. Mitchell, PlanEcon, Inc., Washington, DC 20005 from: Vestnik Moskovskogo Universiteta, geografiya, 1988, No. 6, pp. 53-62. 相似文献
7.
K. A. Salishchev 《地理信息系统科学与遥感》2013,50(3):167-174
The author defines cartographic space, i.e., the space encompassed by geographic maps, as the entire “geographic” envelope. Maps as spatial models of the concrete three-dimensional space of this envelope [increasingly this space is viewed as four-dimensional, when the element of time is included] depict geosystems of various levels and complexity and serve as an essential basis for analyzing their properties, internal processes, and relationships. The author argues against divorcing the study of cartographic space from an understanding of the content of the objects being mapped, and critically evaluates positions of other Soviet and East European cartographers on the “dual role” of the cartographic space of maps. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1986, No. 2, pp. 3-9. 相似文献
8.
基于地面试验的植被覆盖率估算模型及其影响因素研究 总被引:1,自引:0,他引:1
以植被覆盖率的遥感反演为研究主线,以玉米作物为例,在基于地面试验获得作物光谱、叶面积指数和多角度覆盖率的基础上,对目前普遍采用的两种基于植被指数的植被覆盖率估算模型进行了精度比较,同时对植被覆盖率反演的影响因子(叶面积指数、植被空间分布和观测角度)进行了分析.由此得到:估算植被覆盖率的最优植被指数为归一化植被指数;叶面积指数对植被指数与植被覆盖率间关系的影响随植被的生长不断增大;植被空间分布对垂直覆盖率的估算影响很小.对于多角度覆盖率有这样的规律,即在4种空间分布下,以0°观测天顶角(VZA)为中心,在相反方位角上随VZA的增加,覆盖率值基本呈对称分布;在玉米刚出苗时,覆盖率随VZA的增加而增加,当VZA=0°时达到最小值,而随着玉米的进一步生长,4种分布条件下覆盖率随VZA的增加反而降低,在VZA=0°时达到最大值. 相似文献
9.
10.
11.
12.
13.
14.
15.
The authors present the results of experiments in the use of remote sensing imagery for construction of maps depicting human modification of nature. Four diverse areas within the USSR were selected as mapping sites, providing a broad range of environmental and land-use characteristics for investigation. Human impacts were most effectively mapped for two desert sites. The authors recommend combining satellite imagery with terrestrial spectrometric observations or color-infrared photography in investigations of environmental change in steppeland and forested territory. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1984, No. 6, pp. 11-18. 相似文献
16.
17.
基于Multigen Creator和Vega的虚拟现实探讨 总被引:31,自引:2,他引:31
应用Multigen Creator和Vega,对面积约为2km^2的商业街进行三维建模和视景仿真,实现了在桌面PC平台下的虚拟现实环境。 相似文献
18.
准确有效去除干涉纹图中的平地相位是精确莺建DEM的关键.探讨了两类常见的去平地相位方法(基于地理定位和基于干涉频谱),分析了其所引起的误差影响.通过Envis砒和JERS-1两种数据的验证结果表明:在可获取精密轨道数据的情况下,基于地理定位的去平地方法能够有效去除干涉纹图中所包含的平地相位,并很好地控制最终所得的DEM误差,其效果优于基于干涉频谱的去平方法;基于干涉频谱的去平方法在干涉频谱平均空间频率为0时,所引起的DEM误差相对较小;在精密轨道数据缺乏的情况下,两种方法均不能满足重建DEM精度要求. 相似文献
19.
基于多时相Landsat数据的城市扩张及其驱动力分析 总被引:10,自引:0,他引:10
以长沙市为例,在多时相Landsat遥感数据支持下,采用监督分类、非监督分类和归一化裸露指数(NDBI)等方法提取城市用地信息。通过对比多期城市用地的熵值变化,定量分析城市扩张的时空特性; 运用叠加、缓冲区分析等方法,分析城市扩张和中心城区的关系,绘制城市扩张速度玫瑰图。研究结果表明,长沙市建成区总面积不断扩展,其中,1973~1986年扩张主要表现在东南方向,1987~1993年为西部方向,1994~2001年南和东南方向成为快速扩张方向; 对长沙城市扩张驱动力进行分析,认为人口迅速增加是城市扩张的最主要驱动力。 相似文献