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With the high deforestation rates of global forest covers during the past decades, there is an ever-increasing need to monitor forest covers at both fine spatial and temporal resolutions. Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat series images have been used commonly for satellite-derived forest cover mapping. However, the spatial resolution of MODIS images and the temporal resolution of Landsat images are too coarse to observe forest cover at both fine spatial and temporal resolutions. In this paper, a novel multiscale spectral-spatial-temporal superresolution mapping (MSSTSRM) approach is proposed to update Landsat-based forest maps by integrating current MODIS images with the previous forest maps generated from Landsat image. Both the 240 m MODIS bands and 480 m MODIS bands were used as inputs of the spectral energy function of the MSSTSRM model. The principle of maximal spatial dependence was used as the spatial energy function to make the updated forest map spatially smooth. The temporal energy function was based on a multiscale spatial-temporal dependence model, and considers the land cover changes between the previous and current time. The novel MSSTSRM model was able to update Landsat-based forest maps more accurately, in terms of both visual and quantitative evaluation, than traditional pixel-based classification and the latest sub-pixel based super-resolution mapping methods The results demonstrate the great efficiency and potential of MSSTSRM for updating fine temporal resolution Landsat-based forest maps using MODIS images. 相似文献
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1∶25万、1∶100万基础数据是江苏省地理空间信息基础框架的重要组成部分,本文根据江苏省地理空间信息基础框架的要求,结合全省现有的基础地理数据库建设的现状,叙述了对全省范围内的17幅1∶25万DLG、DOM,4幅1∶100万DLG数据如何进行修测、更新和入库,并建立相应的元数据库的过程和方法。 相似文献
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The Nu Expression for Probabilistic Data Integration 总被引：4，自引：0，他引：4
The general problem of data integration is expressed as that of combining probability distributions conditioned to each individual
datum or data event into a posterior probability for the unknown conditioned jointly to all data. Any such combination of
information requires taking into account data interaction for the specific event being assessed. The nu expression provides
an exact analytical representation of such a combination. This representation allows a clear and useful separation of the
two components of any data integration algorithm: individual data information content and data interaction, the latter being
different from data dependence. Any estimation workflow that fails to address data interaction is not only suboptimal, but
may result in severe bias. The nu expression reduces the possibly very complex joint data interaction to a single multiplicative
correction parameter ν
0, difficult to evaluate but whose exact analytical expression is given; availability of such an expression provides avenues
for its determination or approximation. The case ν
0=1 is more comprehensive than data conditional independence; it delivers a preliminary robust approximation in presence of
actual data interaction. An experiment where the exact results are known allows the results of the ν
0=1 approximation to be checked against the traditional estimators based on assumption of data independence. 相似文献
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土地调查数据库更新模型研究 总被引：1，自引：0，他引：1
土地调查数据是国土管理的基础数据之一，日常变更频繁，变化复杂多样。本文通过对土地调查工作和土地调查数据的分析，针对土地调查数据库更新的要求，建立了地类图斑、线状地物和零星地物的土地调查数据更新模型，较好地表达了土地调查数据的更新过程，并利用示例对更新模型进行说明和检验，从而实现对土地调查数据库准确有效地更新。 相似文献
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现势性强的土地利用现状图库是搞好国土资源管理工作的必备图库之一,它对于摸清家底、集体土地所有权登记发证、土地征收征用、宏观决策等具有重要意义。本文从统一空间框架、与国土业务紧密结合的角度探讨如何构建可动态更新的土地利用现状图库,具有一定的创新,对于提升国土资源的信息化管理水平具有一定的借鉴作用。 相似文献