被动微波反演裸露区土壤水分综述   总被引：4，自引：1，他引：4  

韩念龙  陈圣波  汪自军  包书新  宋金红 《吉林大学学报(地球科学版)》2007,(Z1)

被动微波具有全天候、穿透性以及不受云的影响等特征,使其在反演土壤水分时具有很大的优势。通过研究发现,被动微波遥感是反演土壤水分的各种技术中最有效的方法之一。概括了主要的被动微波传感器并从被动微波遥感的原理出发,针对被动微波遥感裸露区地表随机粗糙面的模型以及土壤水分反演算法作了简要介绍。  相似文献   

探地雷达信号特征分析和分辨率提高方法研究   总被引：3，自引：0，他引：3  

王牧男  曾昭发  黄玲  姚健 《吉林大学学报(地球科学版)》2007,(Z1)

探地雷达信号的奇异点或突变点作为雷达信号的重要特征通常反映介质重要信息,如电性变化界面或异常体等。分析了探地雷达信号在Hilbert变换下,利用小波变换确定探地雷达信号奇异点位置的方法。解决了传统傅立叶变换只能从整体检测探地雷达信号奇异性的局限性。并且由于小波变换良好的时频局部化特性,进一步讨论了其在提高探地雷达信号分辨率的研究中的应用。  相似文献   

1:25万地质图空间数据库的建立   总被引：1，自引：0，他引：1  

王刚  孟涛  邢立新  韩冬 《吉林大学学报(地球科学版)》2007,(Z1)

建立地质图空间数据库是将通过调查得到的数据整理后进行属性数据、图形数据采集,利用GIS软件形成不同格式的地质图空间数据库从而达到数据库存储、查询、分析、检索的目的,并实现信息共享。通过利用MAPGIS软件以及基于MAPGIS上开发的RGMAP数字填图系统建立1∶25万地质图空间数据库,分析了数据库的内容和功能,重点提出了建库过程中应该注意的问题。  相似文献   

Erratum to: LICOM Model Datasets for the CMIP6 Ocean Model Intercomparison Project     

Pengfei LIN  Zhipeng YU  Hailong LIU  Yongqiang YU  Yiwen LI  Jirong JIANG  Wei XUE  Kangjun CHEN  Qian YANG  Bowen ZHAO  Jilin WEI  Mengrong DING  Zhikuo SUN  Yaqi WANG  Yao MENG  Weipeng ZHENG  Jinfeng MA 《大气科学进展》2020,37(6):662-662

  相似文献   

活动断裂带的壤中气汞量测量研究   总被引：2，自引：0，他引：2  

刘树田  邓金宪 《地质论评》1998,44(5):547-552

在覆盖区应用壤中气汞量测量研究活动断裂是一种新方法,它不仅能较准确地确定活动断裂的位置,还可以确定其产状,规模,活动性及相对强度,甚至可以作为确定断裂力学性质的参考,本文简棕了断裂带壤中气汞量测量的基本原理,并以长江三峡,长春,吉林等地利用该种方法研究活动断裂的成果为例,说明该项研究的效果及应用前景。  相似文献   

Land cover change detection in West Jilin using ETM ＋ images     

EdwardM.Osei Jr. ZHOUYun-xuan 《东北亚地学研究》2004,7(1):74-84

In order to assess the information content and accuracy of Landsat ETM digital images in land cover change detection,change-detection techniques of image differencing, normalized difference vegetation index,principal components analysis and tasseled-cap transformation were applied to yield 13 images. These images were thresholded into change and no change areas. The thresholded images were then checked in terms of various accuracies. The experiment results show that kappa coefficients of the 13 images range from 48.05-78.09. Different images do detect different types of changes. Images associated with changes in the near-inflared-reflectance or greenness detects crop-type changes and changes between vegetative and non-vegetative features. A unique means of using only Landsat imagery without reference data for the assessment of change in arid land are presented. Images of 12t June, 2000 and 2‘d June, 2002 are used to validate the means. Analyses of standard accuracy and spatial agreement are performed to compare the new images (hereafter called “change images” ) representing the change between the two dates. Spatial agreement evaluates the conformity in the classified “change pixels” and “no-change pixels” at the same location on different change images and comprehensively examines the different techniques. This method would enable authorities to monitor land degradation efficiently and aeculately.  相似文献   

Elastic-plastic analysis for pile-anchor supporting system of deep foundation pit     

JIN Yingyu  BAI Yu College of Construction Engineering  Jilin University  Changchun  China 《东北亚地学研究》2009,(4):236-240

By using numerical analysis methods to simulate the deep excavation, a lot of analyses are established on the basis of two-dimensional plane strain, ignoring the fact that foundation pit possesses three dimensions. For soil constitutive relation, people always take linear and nonlinear model, without considering the plastic behavior of soil. Using plastic-elastic hardening model to simulate constitutive relation of soil characteristics, the authors carried out mechanical analysis for pit excavation and support. The results show that the analysis for the stress state of pile anchor system is an effective way which provides theoretical basis for calculation of soil displacement.  相似文献   

Causes of rockfalls in Al-Huwayshah area,Yemen     

Aref M.O.AL-JABALI  Abdo S.AL-MAQTARY  Hussein AL-AKHALI  Mohammed HAZAEA  Fadel AL-AGHBARI 《东北亚地学研究》2009,(1)

According to topography of Yemen,most areas and villages are located at obligated crest,toe of mountain and under cliffs.Therefore Al-Huwayshah consisting of Tawilah sandstone group is characterized by steep slope reach to 90° in some areas.This area is affected by strong tectonic movements and faults that occurred during the geological epochs.This effect enhances to find out fractures and joints as well as the rocks become brittle and ready to slide depending on the position of area.And there are some frac...  相似文献   

Numerical simulation research on multi-electrodes resistivity imaging survey array     

Jianjun NIU  Xiaopei ZHANG  Lizhi DU College of Construction Engineering  Jilin University  Changchun  China 《东北亚地学研究》2008,11(4):232-236

Multi-electrodes Resistivity Imaging Survey （MRIS） is an array method of electrical survey. In practice how to choose a reasonable array is the key to get reliable survey results. Based on four methods of MRIS such as Wenner, Schlumberger, Pole-pole and Dipole-dipole the authors established the model, by studying the result of the forward numerical simulation modeling and inverse modeling, and analyzed the differences among the different forms of detection devices.  相似文献   

北大西洋秋季“三极子”海温结构对冬季大气环流场的影响   总被引：1，自引：0，他引：1  

时晓曚  孙即霖  孙雅文  毕玮  周旋  衣立 《海洋学报》2015,37(7):33-40

利用NCEP再分析资料、Hadley中心的海表面温度(SST)资料等,从北大西洋秋季海表面温度异常(SSTA)变化入手,对其影响后期冬季大气环流场的机制进行了分析。研究结果如下:(1)北大西洋SST异常与大气环流异常之间存在着相互作用;(2)秋季北大西洋SSTA具有较好的持续性,"正负正"海温异常空间分布导致12月巴伦支海上空500hPa位势高度异常偏高;(3)异常环流形势对应的海表面风异常场(SSWA)通过阶段性风-蒸发-SST异常反馈机制(WES机制)利于海温异常分布的持续及对上空异常大气环流的反馈;(4)三极子海温结构中负异常海温自10月份开始有自西向东的移动,风作用下蒸发加大,伴随上升运动自欧洲西部爱尔兰群岛出现自西向东移动的降水正异常区,潜热释放有利于冬季巴伦支海上空的异常高压脊发展。研究表明,北大西洋秋季SSTA通过阶段性海气相互作用机制影响海洋温度分布和大气环流异常,对后期冬季中国东北部的气候变化产生影响。  相似文献