基于智能定位手机的影像信息内外业一体化核查系统   总被引：1，自引：0，他引：1  

廖永生  丘小春 《测绘与空间地理信息》2015,(12):171-174

在地理国情普查和未来将持续开展的地理国情监测工作中,其主要作业方式是通过多源遥感获取地类信息。由于自动解译和人工解译准确率较低,外业调查和核实都是必不可少的工作。传统的制图调绘核实方法存在人工定位困难、记录慢和单人识别不可靠等问题。采用最新的平板电脑进行外业调绘存在强光下无法显示、笔触操作不便和电池续航时间短等缺点。本系统以GPS智能手机作为终端,通过网络传输将遥感外业调查像片传回内业数据处理中心,作业员可以根据外业作业人员传回的定位像片进行地类赋值或修改以及检查等工作,实现无缝集成的内外业一体化。  相似文献   

利用先验对流层延迟约束加快PPP重新收敛方法     

宋超  郝金明  张鹤 《测绘科学技术学报》2015,(5):441-444

针对卫星信号中断后PPP需要重新收敛的问题,根据对流层延迟参数在短期内变化不大的特点,利用PPP中断前估计的比较精确的对流层延迟参数作为先验信息,提出了一种附加先验对流层信息约束的PPP模型加快PPP的重新收敛。实验结果表明,附加先验对流层信息约束模型的PPP重新收敛过程明显快于传统模型。附加先验对流层延迟信息的标准差越小,约束条件越强,PPP的重新收敛就越快。  相似文献   

1991年8月季风涡旋个例形成的模拟研究     

李箭  葛旭阳  施东雷 《热带气象学报》2020,36(1):72-84

季风涡旋对台风活动有重要的影响, 因此研究季风涡旋的形成机制有利于提高台风预报的准确性。此研究利用中尺度非静力数值模式WRF-ARW模拟1991年8月季风涡旋的生成过程, 并对其生成机制进行分析。模式结果表明, 此次季风涡旋个例是由一个中纬度气旋性低压发展而来。初期中纬度高层正位势涡度的强迫作用有利于对流层低层气旋性低压的发展和维持, 随后高层动力强迫作用减弱, 但中纬度气旋性低压在南移过程中其东南侧对流带逐渐与低纬地区的对流带合并, 使得对流潜热释放增强, 进而使低压在Gill响应的作用下不断加强并最终形成季风涡旋。同时, 涡旋的对流结构表现出明显的非对称性, 因而使其得以维持较大尺度。敏感性试验的结果表明对流层高层强迫对于初始低层扰动的发展至关重要, 而后期热带地区的潜热释放有利于季风涡旋的增强。   相似文献   

Nonstationary time series prediction by incorporating external forces   总被引：2，自引：0，他引：2  

王革丽  杨培才  周秀骥 《大气科学进展》2013,30(6):1601-1607

Almost all climate time series have some degree of nonstationarity due to external forces of the observed system. Therefore, these external forces should be taken into account when reconstructing the climate dy- namics. This paper presents a novel technique in predicting nonstationary time series. The main difference of this new technique from some previous methods is that it incorporates the driving forces in the pre- diction model. To appraise its effectiveness, three prediction experiments were carried out using the data generated from some known classical dynamical models and a climate model with multiple external forces. Experimental results indicate that this technique is able to improve the prediction skill effectively.  相似文献   

Analytical studies of the cloud droplet spectral dispersion influence on the first indirect aerosol effect   总被引：1，自引：0，他引：1  

解小宁  刘晓东 《大气科学进展》2013,30(5):1313-1319

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Shortwave cloud radiative forcing on major stratus cloud regions in AMIP-type simulations of CMIP3 and CMIP5 models   总被引：1，自引：0，他引：1  

张祎  李建 《大气科学进展》2013,30(3):884-907

Cloud and its radiative effects are major sources of uncertainty that lead to simulation discrepancies in climate models. In this study, shortwave cloud radiative forcing (SWCF) over major stratus regions is evaluated for Atmospheric Models Intercomparison Project (AMIP)-type simulations of models involved in the third and fifth phases of the Coupled Models Intercomparison Project (CMIP3 and CMIP5). Over stratus regions, large deviations in both climatological mean and seasonal cycle of SWCF are found among the models. An ambient field sorted by dynamic (vertical motion) and thermodynamic (inversion strength or stability) regimes is constructed and used to measure the response of SWCF to large-scale controls. In marine boundary layer regions, despite both CMIP3 and CMIP5 models being able to capture well the center and range of occurrence frequency for the ambient field, most of the models fail to simulate the dependence of SWCF on boundary layer inversion and the insensitivity of SWCF to vertical motion. For eastern China, there are large differences even in the simulated ambient fields. Moreover, almost no model can reproduce intense SWCF in rising motion and high stability regimes. It is also found that models with a finer grid resolution have no evident superiority than their lower resolution versions. The uncertainties relating to SWCF in state-of-the-art models may limit their performance in IPCC experiments.  相似文献   

Variation of Surface Temperature during the Last Millennium in a Simulation with the FGOALS-g1 Climate System Model     

ZHANG Jie  Laurent LI  ZHOU Tianjun  XIN Xiaoge 《大气科学进展》2013,30(3)

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Remote effects of tropical cyclone wind forcing over the western Pacific on the eastern equatorial ocean     

张荣华  裴玉华  陈大可 《大气科学进展》2013,30(6):1507-1525

An ocean general circulation model （OGCM） is used to demonstrate remote effects of tropical cyclone wind （TCW） forcing in the tropical Pacific. The signature of TCW forcing is explicitly extracted using a locally weighted quadratic least=squares regression （called as LOESS） method from six-hour satellite surface wind data; the extracted TCW component can then be additionally taken into account or not in ocean modeling, allowing isolation of its effects on the ocean in a clean and clear way. In this paper, seasonally varying TCW fields in year 2008 are extracted from satellite data which are prescribed as a repeated annual cycle over the western Pacific regions off the equator （poleward of 10°N/S）; two long-term OGCM experiments are performed and compared, one with the TCW forcing part included additionally and the other not. Large, persistent thermal perturbations （cooling in the mixed layer （ML） and warming in the thermocline） are induced locally in the western tropical Pacific, which are seen to spread with the mean ocean circulation pathways around the tropical basin. In particular, a remote ocean response emerges in the eastern equatorial Pacific to the prescribed off-equatorial TCW forcing, characterized by a cooling in the mixed layer and a warming in the thermocline. Heat budget analyses indicate that the vertical mixing is a dominant process responsible for the SST cooling in the eastern equatorial Pacific. Further studies are clearly needed to demonstrate the significance of these results in a coupled ocean-atmosphere modeling context.  相似文献   

ANALYSES OF THE DYNAMIC EFFECTS ON WINTER CIRCULATION OF THE TWO MAIN MOUNTAINS IN THE NORTHERN HEMISPHERE——Ⅱ.VERTICAL PROPAGATION OF PLANETARY WAVES          下载免费PDF全文

邹晓蕾  吴国雄  叶笃正 《Acta Meteorologica Sinica》1992,(4)

A linear,hemispheric and stationary spectral model with multilayers in the vertical was employed to simulate thevertical propagation of waves triggered by mountains.Results show that,in cooperation with the East Asia zonal meanflow,Tibetan Plateau can excite a strong wavenumber 1 perturbation in the stratosphere with its ridge and trough lo-cated over the Pacific and Atlantic Oceans respectively.On the other hand,the stratospheric wavenumber 1 perturbationcaused by the mechanical forcing of the Rocky Mountains in cooperation with the North America zonal mean flow isvery weak.Calculations from observational data of the vertical profile of critical wavenumber for vertically propagatingwaves imply that the tropospheric wavenumber 1 perturbation can hardly penetrate the North America tropopause up-wards,whereas it can freely propagate through the East Asia tropopause into the stratosphere.Two-dimensional E-Pcross-sections obtained from both observational data and simulated results also demonstrate that waves excited by theRocky Mountains are refracted towards low latitudes in the troposphere during their upward propagation:whereas,inaddition to the above mentioned equatorward leaning branch,the wavenumber 1 and 2 planetary waves excited by theTibetan Plateau possess another branch which is refracted to high latitudes during upward propagation and penetratesthe tropopause into the stratosphere.It is therefore concluded that the difference in the horizontal and vertical wavepropagations in the two hemispheres is a result of the different dynamical forcing induced by the two main mountains inthe Northern Hemisphere.  相似文献   

EXTERNAL CONTROL OF NONMETROPOLITAN INDUSTRY IN KENTUCKY     

Robert G. Cromley  Thomas R. Leinbach 《The Professional geographer》1986,38(4):332-342

The organizational separation of management and other quaternary activities from production operations in American manufacturing has resulted in a divergent pattern of production and headquarter locations. We examine the external control relationships that arise from this separation between headquarter location and branch plant operations in nonmetropolitan Kentucky. Although corporate headquarters have diffused to the Sunbelt, no shift was found in the corporate control of branch plants in Kentucky. Nonmetropolitan manufacturing in Kentucky was oriented toward the metropolitan centers of the traditional manufacturing belt rather than the newer corporate centers of the South. Also control relationships are more likely to be local among smaller factories. Large plants having more autonomy in production or producing finished goods were more likely to be owned by a distant firm located in a large SMSA.  相似文献