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101.
探讨了我国原有地方坐标系与CGCS2000坐标系的定义差别,在我国相关学者研究成果的基础上,设计一种基于布尔莎七参数转换模型的坐标系统转换方法,可以实现除高等级大地控制点之外的各种地理信息数据从原有地方坐标到CGCS2000坐标的快速转换。  相似文献   
102.
The implementation of the Natura 2000 network of marine protected areas under the European Habitats Directive (92/43/EEC) has far-reaching implications for fisheries. To date, no consistent approaches have been established to develop fisheries management measures in Natura 2000 areas, and no European member state has proposed any fisheries measures to the European Commission for consideration under the Common Fisheries Policy. Four key issues are identified in the relationship between fisheries and Natura 2000, and the possible role that the future Common Fisheries Policy could have in this context is discussed. There is a need (1) for a consistent framework to integrate scientific advice, stakeholder participation and management in the management process; (2) for a common methodology to prioritize conservation objectives, in particular for transboundary protected areas; (3) for a consistent framework to assess and evaluate fisheries impacts to define management measures; and (4) to define spatial properties for fisheries. The results from the projects EMPAS (Germany), FIMPAS (the Netherlands), and INDEMARES (Spain) and the Dogger Bank case are discussed.  相似文献   
103.
Airborne laser scanning (ALS) is increasingly being used for the mapping of vegetation, although the focus so far has been on woody vegetation, and ALS data have only rarely been used for the classification of grassland vegetation. In this study, we classified the vegetation of an open alkali landscape, characterized by two Natura 2000 habitat types: Pannonic salt steppes and salt marshes and Pannonic loess steppic grasslands. We generated 18 variables from an ALS dataset collected in the growing (leaf-on) season. Elevation is a key factor determining the patterns of vegetation types in the landscape, and hence 3 additional variables were based on a digital terrain model (DTM) generated from an ALS dataset collected in the dormant (leaf-off) season. We classified the vegetation into 24 classes based on these 21 variables, at a pixel size of 1 m. Two groups of variables with and without the DTM-based variables were used in a Random Forest classifier, to estimate the influence of elevation, on the accuracy of the classification. The resulting classes at Level 4, based on associations, were aggregated at three levels — Level 3 (11 classes), Level 2 (8 classes) and Level 1 (5 classes) — based on species pool, site conditions and structure, and the accuracies were assessed. The classes were also aggregated based on Natura 2000 habitat types to assess the accuracy of the classification, and its usefulness for the monitoring of habitat quality. The vegetation could be classified into dry grasslands, wetlands, weeds, woody species and man-made features, at Level 1, with an accuracy of 0.79 (Cohen’s kappa coefficient, κ). The accuracies at Levels 2–4 and the classification based on the Natura 2000 habitat types were κ: 0.76, 0.61, 0.51 and 0.69, respectively. Levels 1 and 2 provide suitable information for nature conservationists and land managers, while Levels 3 and 4 are especially useful for ecologists, geologists and soil scientists as they provide high resolution data on species distribution, vegetation patterns, soil properties and on their correlations. Including the DTM-based variables increased the accuracy (κ) from 0.73 to 0.79 for Level 1. These findings show that the structural and spectral attributes of ALS echoes can be used for the classification of open landscapes, especially those where vegetation is influenced by elevation, such as coastal salt marshes, sand dunes, karst or alluvial areas; in these cases, ALS has a distinct advantage over other remotely sensed data.  相似文献   
104.
2000国家大地坐标系(CGCS 2000)的启用,对原有的测绘成果将产生直接影响。为确保常用测量坐标系与CGCS 2000的衔接和转换,需要有效地整合原有的测绘基础数据,探究地方测量坐标系与CGCS 2000之间的转换方法,确定地方坐标系与CGCS 2000之间的联系。本文分析了石家庄市原有的基础测绘数据分析,提出了平面控制网整合方案和坐标整体转换方法。  相似文献   
105.
讨论了手持式GPS仪改正参数的内业确定方法 ,并给出了利用Excel表格进行计算的具体解决方案。与传统方法相比,本方法具有完全室内作业、省时省力、参数可靠性高的特点。  相似文献   
106.
The amplitude and rhythm of temperature changes at inter-decadal and inter-centennial timescale were studied, based on the winter-half year temperature change series reconstructed from historical phenological events in eastern China for the past 2000 years, together with the temperature change simulation from ECHO-G model for the past 1000 years, and the quasi-periods of temperature fluctuation were discussed by using wavelet analysis. The results indicate: 1) the maximal amplitude of winter half-year temperature change in eastern China at decadal and centennial scale, was above 2℃ and 0.5-1.0℃ respectively. The reconstructed result indicates that the amplitude of warming during the 20th century was identical with the maximum amplitude before the 20th century in eastern China, but the simulated result suggests that the amplitude of warming has exceeded the maximum amplitude. 2) The rhythms of temperature change at centennial to millennial scale in eastern China were about 100-year, 250-year, 400-year, 600-year and 1000-year. The 20th century, the 1st-3rd century and the 9th-13th century were warm peaks at inter-centennial scale as well as at millennial scale. It is implicated that the warming during the 20th century should be attributed to not only anthropogenic effect, but also natural climate variation.  相似文献   
107.
In recent years, the data collecting and processing of magnetotelluric sounding (MT) have progressed greatly. How to improve the quality of field surveyed data and obtain the high quality parameters such as apparent resistivity and phase is the most important link during the overall flow. It is closely related to the signal-to-noise ratio of magnetic sensors, the resolution of data collecting units and relevant processing methods as well. Produced by Germany Metronix Measurement Instruments and Electronics Ltd., the new type multi-channel geophysical measurement system GMS-06 was already adopted and used by domeslic units such as Institute of Geology and Geophysics of Chinese Academy of Sciences and Tongji University. Based on the brief introduction of GMS-06, this paper will give the comparisons and analyses of the synchronous surveyed MT data by GMS-06, MMS-03 MT system which was also produced by Metronix and V5-2000 MT system produced by Canada Phoenix Geophysics Ltd.. Then the preliminary processing and interpretation results of the long period MT data observed by GMS-06 in the area of Shanghai and Zhejiang are also discussed in the paper.  相似文献   
108.
从讨论ISO 9000:2000标准“设计和开发”的定义出发,对地质勘查组织的的产品、产品质量特性和产品的设计进行了讨论,提出了地质勘查组织产品设计与标准中规定的设计和开发的概念以及对应关系,并对标准中的“设计和开发”与地质勘查组织“设计与开发”的内容进行了对比分析。  相似文献   
109.
中国现代大地基准——中国大地坐标系2000(CGCS 2000)及其框架   总被引:19,自引:2,他引:17  
陈俊勇 《测绘学报》2008,37(3):269-271
简要介绍2008年7月1日启用的中国地心坐标系统2000 (CGCS 2000)的定义及其采用的大地测量基本常数,并对CGCS 2000的坐标框架进行了评述:它应该是高精度,涵盖全部陆海国土,动态,具有方便用户的密度和分布,它由全球导航卫星系统国家级连续运行站网和国家高精度大地控制网这两部分组成.目前的框架由2000国家GPS大地网和它与全国天文大地网联合平差的成果构成,可以满足近期的需求.采用CGCS 2000后将引起中国境内地面奌的大地经纬度值、高斯平面坐标值、地图上点间的方向和长度值等的变动,本文给出了相应的变动值和应对的基本思路.  相似文献   
110.
浅谈地球坐标系及2000国家大地坐标系   总被引:1,自引:1,他引:0  
介绍了地球坐标参考系统和国际地球参考系及参考框架;阐述了2000国家大地坐标系,指出2000国家大地坐标系可按精度划分为国家级连续运行基准站、GPSA、B级网、天文大地网三个层次。  相似文献   
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