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991.
基于分水岭算法的高分遥感图像道路提取优化方法 总被引:2,自引:0,他引:2
针对高分辨率遥感图像城市道路提取中存在的问题,在面向对象方法和数学形态学等理论基础上,提出了一种基于改进的分水岭分割算法的道路提取方法.在图像预处理基础上,首先使用改进的分水岭算法分割影像,提取基本的道路信息;然后利用面向对象方法提取道路基元,完善道路信息;最后将道路信息二值化,并采用数学形态学等方法进行优化,去除和修补不完善的道路.结果表明,该方法能有效地提取出城市地区的道路信息,对较复杂的道路环境也有较好的效果. 相似文献
992.
在GPS现代化下,研究多频卫星导航定位的关键技术,利用现有的双频观测值去模拟L5载波相位观测值,然后根据网络RTK基准站连续观测的特点,利用基准站坐标精确已知的条件,研究多频模式下基准站间的整周模糊度求解。通过分析,在不同基线长度下,多频模式下的基准站间模糊度求解比双频模式下更加可靠,求解整周模糊度更加便捷。 相似文献
993.
多条带WorldView卫星图像几何定位精度分析 总被引:2,自引:1,他引:1
本文针对多个条带WorldView卫星图像,研究了基于有理函数模型的附加参数区域网平差方法,对高分辨率卫星图像定位精度进行了详细分析。青海地区WorldView卫星图像试验结果表明:无地面控制点时,多条带整体区域网定位结果优于各个条带单独平差结果,区域网平差方法结果优于直接前方交会方法;有地面控制点时,多条带区域网平差结果与各个条带单独平差结果相当,且沿路线不大于10km布设一个地面控制点,其精度可满足1∶2000比例尺加密精度要求,可用于公路初步设计。 相似文献
994.
The LAMBDA method that was proposed by Teunissen is introduced. Then, on the basis of both the back-sequential conditional LS technique and the upper-triangular Cholesky decomposition, another form for LAMBDA method is proposed. This new form for LAMBDA method has the same principle and calculation speed as the traditional LAMBDA method. 相似文献
995.
Alireza Hamedianfar 《国际地球制图》2013,28(3):268-292
Urban areas consist of spectrally and spatially heterogeneous features. Advanced information extraction techniques are needed to handle high resolution imageries in providing detailed information for urban planning applications. This study was conducted to identify a technique that accurately maps impervious and pervious surfaces from WorldView-2 (WV-2) imagery. Supervised per-pixel classification algorithms including Maximum Likelihood and Support Vector Machine (SVM) were utilized to evaluate the capability of spectral-based classifiers to classify urban features. Object-oriented classification was performed using supervised SVM and fuzzy rule-based approach to add spatial and texture attributes to spectral information. Supervised object-oriented SVM achieved 82.80% overall accuracy which was the better accuracy compared to supervised per-pixel classifiers. Classification based on the proposed fuzzy rule-based system revealed satisfactory output compared to other classification techniques with an overall accuracy of 87.10% for pervious surfaces and an overall accuracy of 85.19% for impervious surfaces. 相似文献
996.
DEM产品分辨率是其质量和精度的重要表现。目前,关于DEM的分辨率研究,主要以实验方法或公式法进行分析比较确定区域DEM的最佳分辨率;这些研究对于具体应用具有一定的指导意义,但是对于DEM产品的分辨率确定往往引起了混淆。本文从地貌选取指标出发,对DEM产品分辨率进行分析研究,对其适用性的指导也有一定帮助。 相似文献
997.
别开红 《测绘与空间地理信息》2013,36(7):146-148
随着空间技术的发展,遥感图像的分辨率越来越高。其重要性日渐显露。遥感图像处理的发展目标之一就是实现自动的识别及目标信息的自动提取。利用高分辨率的卫星(如快鸟卫星)影像识别地面目标是急需的,本文仅以遥感影像的水体提取为例。 相似文献
998.
《The Professional geographer》2013,65(4):471-477
Much science-fiction literature is based upon the creation and exploration of alternative environments. Stanley G. Weinbaum's short story, “Parasite Planet,”introduces an unusual environment that may be wrong in the light of recent evidence on Venus but still stimulates the geographical imagination. 相似文献
999.
《International Journal of Digital Earth》2013,6(3):235-257
The accuracy of topographic correction of Landsat data based on a Digital Surface Model (DSM) depends on the quality, scale and spatial resolution of the DSM data used and the co-registration between the DSM and the satellite image. A physics-based bidirectional reflectance distribution function (BRDF) and atmospheric correction model in conjunction with a 1-second DSM was used to conduct the analysis in this paper. The results show that for the examples used from Australia, the 1-second DSM, can provide an effective product for this task. However, it was found that some remaining artefacts in the DSM data, originally due to radar shadow, can still cause significant local errors in the correction. Where they occur, false shadows and over-corrected surface reflectance factors can be observed. More generally, accurate co-registration between satellite images and DSM data was found to be critical for effective correction. Mis-registration by one or two pixels could lead to large errors of retrieved surface reflectance factors in gully and ridge areas. Using low-resolution DSM data in conjunction with high-resolution satellite images will also fail to correct significant terrain components where they occur at the finer scales of the satellite images. DSM resolution appropriate to the resolution of satellite image and the roughness of the terrain is needed for effective results, and the rougher the terrain, the more critical will be the accurate registration. 相似文献
1000.
Iuliia Shustikova Alessio Domeneghetti Jeffrey C. Neal Paul Bates Attilio Castellarin 《水文科学杂志》2013,58(14):1769-1782
ABSTRACT This study evaluates and compares two-dimensional (2D) numerical models of different complexities by testing them on a floodplain inundation event that occurred on the Secchia River (Italy). We test 2D capabilities of LISFLOOD-FP and HEC-RAS (5.0.3), implemented using various grid sizes (25–100 m) based on 1-m DEM resolution. As expected, the best results were shown by the higher-resolution grids (25 m) for both models, which is justified by the complex terrain of the area. However, the coarser resolution simulations (50 and 100 m) performed virtually identically compared to the high-resolution simulations. Nevertheless, the spatial distribution of flood characteristics varies: the 50 and 100 m results of LISFLOOD-FP and HEC-RAS misestimated flood extent and water depth in selected control areas (built-up zones). We suggest that the specific terrain of the area can cause ambiguities in large-scale modelling, while providing plausible results in terms of the overall model performance. 相似文献