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介绍了 ADS40数码航摄相机及其获取影像的技术特点,重点分析了利用 ADS40数码航摄影像进行测图实践过程中的立体建模和立体测图的技术特点,以及利用 ADS40数码航摄影像进行1:2000地形图制作的可行性。 相似文献
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针对ADS40影像的物方空间投影几何约束,提出了一种基于扫描线投影中心平面几何约束的ADS40物方反投影坐标计算快速算法,有效地改进了最佳扫描线的搜索效率.实验表明,该算法可以有效地提高ADS40影像物方反投影坐标计算的效率. 相似文献
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分析了ADS40影像的几何特性和相机检校模型,设计了一套针对ADS40系统的检校方案,并基于地面检校场的实际数据进行了验证。实验结果表明,通过合理的检校,可以获得ADS40高精度的检校文件,提高摄影测量的精度,并降低对控制点的依赖性。 相似文献
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ADS40机载多波段数字传感器因为具有高精度POS系统以及直接获取数字影像等特点而备受业界关注。ADS40影像的数据生产体系比以往的生产体系有着明显的优势,介绍了基于ADS40广州市1:2 000正射影像图的测制技术、生产流程及成果管理与应用。 相似文献
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提出了一种利用机裁定位定向系统(POS)数据辅助航空影像进行影像匹配和变化检测的方法。首先利用带POS数据的老影像解求新影像的外方位元素,然后在老立体影像上提取特征点,根据前方交会和共线条件方程得到新影像上同名点的近似位置,再与新影像进行匹配,寻找匹配不好的点作为变化区域的初始位置。以此为基础选择精检测窗口,进行边缘提取和跟踪,并进行链码匹配,最终确定发生变化的区域。试验证实,本文方法是可行的。 相似文献
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叶片生化组分浓度对单叶光谱影响研究——以2100nm吸收特征的碳氮比反演为例 总被引:13,自引:0,他引:13
运用连续统去除法和波深归一化方法对构成植物叶片碳氮比的基本因素——总碳和总氮浓度进行深入研究,对其组成物质的浓度差异在2030—2220nm区间内光谱响应的物理机制进行深入分析。在对多组典型叶片的对比分析后发现,经连续统去除后的相对反射率光谱中可以明显观察到碳、氮浓度差异造成的影响,而其影响与纤维素、木质素和蛋白质在此范围的吸收特征密切相关。其中,以纤维素和木质素为代表的碳浓度的影响主要体现在2030—2050nm区间,而以蛋白质为代表的氮浓度的影响则体现在2054nm和2172nm附近存在的斜率突变上。另外利用波深归一化方法再次证明了氮浓度对2054nm和2172nm处光谱特征的影响,进一步证实蛋白质双峰特征在光谱上的响应,并通过相关分析和回归分析验证了相对反射率光谱与碳氮比之间的定量关系。 相似文献
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Francis A. Fajemirokun 《Journal of Geodesy》1975,49(2):149-166
The tables of systematic differences between the FK4 catalogue and the GC and N30 catalogues, published by Brosche et al.
(1964) are evaluated for the epoch of 1970.0. Mean star positions in the three catalogue system are updated to the epoch of
1970.0 and systematic corrections are applied to the GC and N30 positions. Residuals are obtained before and after systematic
corrections, and these residuals are compared. Results show that most of the systematic differences between the three fundamental
catalogue systems are eliminated if tabulated corrections are applied to the GC and N30 mean positions of stars. 相似文献
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接收机天线相位偏差是GPS定位中一项重要的误差源,其影响值可达数毫米至数厘米,为了解接收机天线性能及稳定性等方面的情况,在出测前后一般对相位中心的稳定性进行检验。目前已采用两种方法对Ashtech扼流圈天线相位中心稳定性进行了测试,证明了AshtechZ-12型接收机天线满足限差要求及试验方法的可行性,本文将就此作具体介绍。 相似文献
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在 1:2 50 0 0 0地图数据库生僻汉字统计的基础上 ,通过生僻汉字的编码、字模的制作、代码的编制、输入法的生成以及矢量汉字的使用等 ,提出了在GBK的基础上进行再扩展的技术和方法 ,从而解决了数字制图中生僻汉字处理的问题。 相似文献
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Bernhard Jenny Daniel M. Stephen Ian Muehlenhaus Brooke E. Marston Ritesh Sharma Eugene Zhang 《制图学和地理信息科学》2018,45(1):62-75
Origin-destination flow maps are often difficult to read due to overlapping flows. Cartographers have developed design principles in manual cartography for origin-destination flow maps to reduce overlaps and increase readability. These design principles are identified and documented using a quantitative content analysis of 97 geographic origin-destination flow maps without branching or merging flows. The effectiveness of selected design principles is verified in a user study with 215 participants. Findings show that (a) curved flows are more effective than straight flows, (b) arrows indicate direction more effectively than tapered line widths, and (c) flows between nodes are more effective than flows between areas. These findings, combined with results from user studies in graph drawing, conclude that effective and efficient origin-destination flow maps should be designed according to the following design principles: overlaps between flows are minimized; symmetric flows are preferred to asymmetric flows; longer flows are curved more than shorter or peripheral flows; acute angles between crossing flows are avoided; sharp bends in flow lines are avoided; flows do not pass under unconnected nodes; flows are radially distributed around nodes; flow direction is indicated with arrowheads; and flow width is scaled with represented quantity. 相似文献
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The matrixt distribution is derived and its properties are shown which are applied for the Bayesian inference in the multivariate linear
model. By this approach hypothesis tests for the multivariate model are derived which are less sensitive than the tests of
the sampling theory. Examples of their application in the analysis of data for the detection of deformations are given. 相似文献