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   

南极海冰变化异常与全球海平面变化(英)   总被引：1，自引：0，他引：1  

XIE Si-Mei  ZOU Bin  WANG Yi  BAO Cheng-Lan 《冰川冻土》1998,(4)

In this paper, the long-term variation trend of the Antarctic sea ice in 1973～1994 and the inter-decade variation rule of the global sea level are analyzed. It is foundthat, the Antarctic sea ice area in 1980's was significantly less than in 1970's but with regional difference:decreasing in Regions Ⅰ, Ⅱ, and Ⅲ, and increasing in Region Ⅳ, the average global sea levelheightvalue in 1980's was also significantly higher than in 1970's but also with very large regional difference.Connecting variation of both to analyze their physical mechanism, it is pointed that, the accumulated seaice anomaly value in 1980's less than in 1970's means a global climate warming, the sea watertemperature and air temperature rising, sea water volume expanding, and more icebergs transportingfrom the ice cover on the Antarctic continent to ocean in the warmer years. As a result, the global sealevel raised significantly with the global average sea level value in 1980's was 22 mm higher than in 1970's. The Sea Level Raising (SLR) distributed uneven. It is especially true in the Pacific Ocean andAtlantic. This kind of uneven SLR distribution closely relates to, or is introduced by the uneven sea ice change of the Antarctic Regions.  相似文献   

气候系统内极区热汇与热带海洋热源之间的相互作用(英)   总被引：2，自引：1，他引：1  

XIE Si-Mei  BAO Cheng-Lan  HAO Chun-Jiang 《冰川冻土》1998,(4)

The anomalous change of two polar sea ice and tropical ocean SST is a very important index for global climate monitoring and prediction. In this paper, the wave resonance principle is used to calculate month by month running cross couple correlation coefficient time series between sea ice in different sea area of two Polars, as well as between them and five elements of E1 Nino events, to analyze their variation features, and to find out their resonance periods. The resonance period of two waves is just the strongest interaction period.Some results are concluded as follows. 1) The Arctic sea ice to the Pacific-side (NPI1) and Atlantic-side (NP12) show a strong positive-negative feedback impact each other to the Antarctic Ross Sea ice (SPI2) with equal intensity. 2) Both NPI1 and NPI2 give a strong positive and negative feedback to the Antarctic Wedded Sea ice (SPI3) while it is rather weak in convercse status. It means that, the Arctic sea ice plays a leading and controlling role on the Wedded Sea ice. 3) SST of Nino 4 area in thecentral equatorial Pacific has a best resonance period with SPI2 with cycle period of 132 months. It closely relates to quasi-11 years oscillation period of both SST of Nino 4 area and SPI2. SST of Nino 4 has also a resonance period to SPI3 with cycle of 61 months. There also exist strong interaction periods between the Antarctic sea ice and other elements of ENSO event but weaker than SST of Nino 4 area.  相似文献   

SPOT5与ERS-2卫星影像的联合立体定位   总被引：3，自引：3，他引：0  

邢帅  张宏伟  韩祥磊  徐青  BAO Yong-qiang 《测绘科学》2009,34(1)

本文将SPOT5与ERS-2卫星影像联立构成一组立体像对,并通过立体定位的方式获取了地面点的三维坐标。根据本文立体像对前方交会的特殊几何图形,推导了立体定位理论精度的计算公式,并利用实验验证了公式的正确性,同时分析了影响立体定位精度的主要因素。实验结果表明,联合具有一定重叠度的SPOT5和ERS-2影像进行立体定位具有很强的可行性,其精度已可以满足部分测绘任务的要求。  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   

利用相关逼近法建立定位与姿态数据的同步模型          下载免费PDF全文

齐珺  暴景阳  周丰年  崔扬  冯金涛 《海洋测绘》2010,30(2):28-31

根据海道测量精密测量的需求,对姿态与定位数据融合的同步方法进行了研究。通过GPS大地高数据和升沉数据,建立了一种基于相关逼近原理的定位与姿态数据同步模型。该模型能够确定定位与姿态数据的相对延时,实现两类数据在同一时间基准下的同步。实例计算表明,定位与姿态数据的相对延迟时间已成为两类数据融合应用中必须考虑的因素。由同步模型解算后,GPS大地高数据与总升沉数据体现了更好的一致性,由此也验证了模型的有效性。  相似文献   

海道测量定位数据后处理的拟合算法研究          下载免费PDF全文

齐珺  暴景阳  黄晓杰  刘雁春 《海洋测绘》2010,30(4):1-4

根据海道测量定位数据后处理的要求,对定位数据后处理中的拟合算法进行了研究,提出了一种基于多面函数拟合的后处理方法,并给出了相应的数学模型。实例结果表明,后处理中采用多面函数拟合法处理测线定位数据可提高定位数据的可靠性,拟合精度可将精密动态定位控制在厘米级。上述方法有利于提高海道测量中海上定位成果的质量。  相似文献   

浅析四道沟金矿矿床成因及找矿方向     

鲍玉学  孙立民  黄俊鹏 《国土资源》1999,(3)

四道沟金矿是地质条件较为复杂的矿床，对其成因问题前人观点众说不一。比较典型的主要有岩浆热液成因和沉积变质成因，成因不同直接影响着找矿方向。根据矿床地质特征和工作实践认为：该矿床成因应为沉积变质－ 岩浆热液叠加改造型矿床。所以沉积变质和岩浆热液成矿的有利条件均应成为找矿的主要方向。据此开展的找矿工作已初步获得突破性进展。  相似文献   

用MODIS数据和分裂窗算法反演内蒙古地区的地表温度   总被引：3，自引：0，他引：3  

包刚  包玉海  李慧静  王萨仁娜 《测绘科学》2009,34(1)

地表温度是气象、水文、生态等研究中一个重要参数。大气透过率和比辐射率是分裂窗算法的两个重要输入参数,本文利用MODIS数据的可见光波段(band1)和近红外波段(band2、19)计算该两个参数;再利用MODIS数据的两个热红外波段(band31、32)和分裂窗算法对内蒙古地区地表温度进行了反演;结果表明,遥感反演出来的地表温度的空间分布与内蒙古气候区地空间分布具有高度的一致性,能直观地反应内蒙古地区地表温度的空间分布特征。  相似文献   

一种基于空时联合约束的相对定位方法     

徐卫明  暴景阳  陆建华 《武汉大学学报(信息科学版)》2009,34(4)

为了降低机动环境对传感器网络自身定位的影响,提出了一种基于空时联合约束的相对定位(STRP)方法.Monte Carlo仿真表明,相对于STF技术,STRP方法降低了环境对定位的影响,自主导航定位的精度提高了36%.  相似文献