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1.
环境减灾卫星是我国第一个专门用于环境与灾害监测预报的小卫星星座,本文基于该卫星热红外数据,采用Jimenez-Munoz和JoseA.Sobrino提出的普适性单通道算法,反演2009年7月2日北京市区的地表温度,并将反演结果和当天的MODIS地表温度产品进行比较,初步认为HJ-1B热红外数据地表温度反演结果较好.最后依据反演得到的地表温度分布图,以及实测气温数据对北京市区的地表温度空间分布进行了简单分析,不同的地表类型温度相差较大,部分受水体、植被影响的区域也呈现低温区,市区建筑密集区属于高温区,机场温度明显高于周围区域,气温与地温呈现相同的趋势.  相似文献   

2.
在缺乏卫星过境时地面同步观测数据的情况下, 大范围高时空分辨率的土壤水分监测存在一定的困难。针对这一问题, 提出一种不依赖地面土壤水分同步观测数据的主、被动微波协同反演逐日高空间分辨率的土壤水分观测新方法。该方法将补偿后的 AMSR-E 土壤水分作为“高时间分辨率土壤水分观测控制值”, 以此计算逐日土壤水分变化量, 并结合 ASAR 交替极化模式数据, 反演高空间分辨率的土壤水分基准日期值, 然后基于两者建立土壤水分协同反演模型。该模型适用于地势比较平坦、地表粗糙度较小且无植被覆盖或植被覆盖度较低的区域。在陕西省渭北台塬西部地区的试验结果表明: 该方法参数拟合的决定系数约为0.81; 反演得到的土壤水分与凤翔县农业气象站地面实测土壤湿度数据对比, 两者的决定系数为 0.92, 土壤体积含水量的均方根误差为0.025。反演结果可用于水分限制条件下作物生长模拟。  相似文献   

3.
表观热惯量法是热红外遥感监测土壤水分的重要方法之一.土壤的表观热惯量可以通过对土壤反照率和地表温度日较差的测量而获得。以吉林中部地区为研究区,根据表观热惯量反演土壤水分含量的原理,选取春播时期的四月份时相,利用MODIS_L1B数据计算模型中的相关参量,进而计算表观热惯量值。将计算结果与土壤水分含量实测值进行线性回归分析,结果通过了置信度0.01的显著水平t检验,相关系数R=0.831,并分析土壤类型对土壤水分含量差异的影响,结果与表观热惯量反演土壤水分的计算结果一致。  相似文献   

4.
利用国产卫星高分一号卫星数据评估其植被第一生产力(NPP)的潜力,对植被指数取值范围、光能利用率、水分指数等参数进行修订,建立适合高分卫星数据的光能利用率模型,反演小尺度草地生态系统的生产力,利用野外观测数据对反演结果进行验证.模型模拟的数值与实测值的拟合度达到0.94,均方差为20.59 g C/(m2·a),并进一步将该结果与该区域同类型研究进行类比分析.结果表明,该模型对小尺度草地NPP估算可行,减少了工作量,为国产高分数据进行草地NPP、尤其煤矿区草地环境的监测提供了可行的技术方法,从而推动国产卫星在该地区的应用.  相似文献   

5.
选取2011年中国东部地区428个测站的PM10质量浓度资料, 用Terra和Aqua MODIS AOD产品的时间分布作为指示数据, 检验日、月、季、年时间尺度下, 卫星过境时刻地面PM数据(SATPM)对地面所有时刻数据平均值(ALLPM)的代表性。结果发现, 在东部大部分地区, SATPM与ALLPM的相对误差在±20%以 内, 且Aqua-MODIS代表性更好。此外, 结合两颗卫星的数据, 经拟合订正获得了新的日、年时间尺度上PM10质量浓度数据, 将其与ALLPM的相关系数从0.87和0.83提高到0.90。此检验结果对于检验卫星数据反演 的PM2.5的代表性也有一定指导意义。  相似文献   

6.
积雪作为冰冻圈主要组成部分,是全球能量和水循环的重要环节.利用卫星遥感技术获取的高时空分辨率的积雪分布和状态信息对寒区水资源管理、经济发展和社会稳定具有重要意义.目前,利用高分辨率光学和合成孔径雷达(Synthetic Aperture Radar,SAR)卫星数据能够实现积雪覆盖范围的识别和雪层物化参数的反演,但识别和反演的精度在高寒山区条件下受地形影响严重.为改进现有识别和反演模型在山区条件下的适应性,以新疆天山北坡玛纳斯河流域为研究区,分别在2013年冬季积雪期和2014年春季融雪期进行了两次与SAR卫星同步的野外积雪观测,为山区积雪识别和积雪参数反演获取了地面实测光谱和积雪参数数据.对两次积雪观测的目的、方法和初步结果进行介绍.观测初步结果显示了积雪在研究区内空间分布不均一,季节性差异性明显,为后续通过高分辨率遥感手段获取山区积雪参数时间和空间变异性提供了基础.  相似文献   

7.
选用Landsat 8TRIS 10数据,采用改进后的普适性单通道算法对淮河流域上游地区卫星影像进行亮度温度反演.利用可见光波段、近红外波段对研究区的地表发射率进行计算,结合大气水分含量反演出研究区真实地表温度,反演精度较高,结果表明改进后的普适性单通道算法在中尺度区域适用性较好.探讨了中、大尺度区域地表温度反演可能面临的问题.  相似文献   

8.
提出了一种基于卫星遥感数据的近地面颗粒物质量浓度(PM值)估计方法 .采用Terra/MODIS卫星数据和基于连续两天MODIS数据的气溶胶光学厚度反演算法,反演出无锡地区的气溶胶光学厚度;再利用所反演的气溶胶光学厚度与地面实测颗粒物质量浓度数据进行分析,得出颗粒物质量浓度的大小分布范围与气溶胶光学厚度的关系模型;进一步利用研究区域中地面站点监测到的颗粒质量浓度数据对估算结果进行评估.结果表明该方法所估算的PM值与地面实测数据具有较好的相关性,且地面监测的颗粒物质量浓度均分布在卫星遥感数据所估算的范围之内.本研究证明了MODIS卫星数据监测地面颗粒物质量浓度的可行性,为近地面PM值的估算提供了有效手段.  相似文献   

9.
环境一号(HJ-1)卫星是我国自发研制的专门用于环境和灾害监测的光学卫星.其数据获取周期短、空间分辨率高,能及时、连续、准确地监测悬浮物浓度时空变化,在内陆二类水体遥感监测方面具有良好的应用前景.该文以长江中游武汉河段为研究区,利用HJ-1卫星CCD数据第1、3波段建立了具有较高精度的悬浮物浓度反演模型,并对2008年11月14日武汉河段悬浮物浓度进行了反演,得到其空间分布图.结果表明,该模型的悬浮物浓度反演均方根误差(RMSE)为8.84mg/L,平均绝对百分比误差(MAPE)为13.6%.从空间分布来看,在武汉附近,长江干流悬浮物浓度高于支流汉江,江心洲滩附近水体悬浮物浓度偏高.  相似文献   

10.
本文主要介绍了GPS测量数据的常用格式RINEX标准文件格式,并利用MATLAB工具计算出所观测卫星里的五颗卫星(14、20、29、31和32五颗)在283个历元的瞬时位置,即所观测时间段里五颗卫星在WGS-84坐标下的空间运行轨迹.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
19.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

20.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

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