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141.
Gürcan Büyüksalih Güven Koçak Murat Oruç Hakan Akçin Karsten Jacobsen 《The Photogrammetric Record》2004,19(107):200-218
TK-350 stereo-scenes of the Zonguldak testfield in the north-west of Turkey have been analysed. The imagery had a base-to-height ratio of 0·52 and covered an area of 200 km × 300 km, with each pixel representing 10 m on the ground. Control points digitised from 1:25 000 scale topographic maps were used in the test. A bundle orientation was executed using the University of Hanover program BLUH and PCI Geomatica OrthoEngine AE software packages. Tests revealed that TK-350 stereo-images can yield 3D geopositioning to an accuracy of about 10 m in planimetry and 17 m in height. A 40 m resolution digital elevation model (DEM) was generated by the PCI system and compared against a reference DEM, which was derived from digitised contour lines provided by 1:25 000 scale topographic maps. This comparison showed that accuracy depends mainly on the surface structure and the slope of the local terrain. Root mean square errors in height were found to be about 27 and 39 m outside and inside forested areas, respectively. The matched DEM demonstrated a systematic shift against the reference DEM visible as an asymmetric shift in the frequency distribution. This is perhaps caused by the presence of vegetation and buildings. 相似文献
142.
Grant H. Thomson 《The Photogrammetric Record》2004,19(107):237-249
The introduction of digital cameras for aerial survey photography and use of scanners with processed aerial film present a number of technical questions concerning the way photography is to be acquired in the future. Among the questions to be addressed are the comparative metric properties of images acquired by each system and the associated image quality characteristics. The new digital camera systems will require very careful appraisal, using well-established methods of assessing metric quality already available to survey organisations. The questions concerning image quality are more difficult to answer, as they require very specialised instrumentation if measurements are to be made directly in practice. Over the course of the past several decades a more analytical approach to assessing image quality has emerged, and one that may be used by individuals. The method is particularly effective where information on the micro-image characteristics of products is made available by the manufacturers concerned. An outline is given of some considerations that need to be taken into account when using an analytical approach, with references given for further reading. 相似文献
143.
哈密南部暴雨成因分析 总被引:6,自引:1,他引:6
通过对 2 0 0 2年 6月 1 8~ 1 9日哈密南部暴雨的环流背景、物理机制、T2 1 3产品的物理量及卫星云图分析 ,揭示形成暴雨的成因 相似文献
144.
145.
A New Model for Quantifying Anisotropic Scale Invariance and for Decomposition of Mixing Patterns 总被引:1,自引:0,他引:1
Qiuming Cheng 《Mathematical Geology》2004,36(3):345-360
A new power–law function has been derived to represent the relationship between area of the set consisting of wave numbers with spectral energy density above S (A(>S)) on the two-dimensional frequency plane and S. The power–law relation holds if the field concerned possessing isotropic scale invariance or generalized scaling invariance involves rotational and ratio-scale changing transforms. The equation is valid for dealing with common exploration geophysical and geochemical fields encountered in mineral exploration and environmental assessment. This power–law function not only provides a new model for characterizing anisotropic scaling invariance for generalized scaling field, for example, estimating the power exponent of power spectrum of generalized scale invariance measure in frequency domain, but also forms a theoretical base for the S–A filtering technique developed for decomposing a mixing field into components on the basis of distinct scaling properties in the frequency domain. It is demonstrated that the method has potential to become a general technique for image processing and pattern recognition. 相似文献
146.
基于神经网络的区域生态环境分类方法研究 总被引:3,自引:0,他引:3
如何利用智能化信息提取技术,进行区域生态环境自动分类,一直是一种前沿性研究。该文在分析研究区自然景观特征的基础上,总结了影响区域生态环境的建模要素,基于神经网络技术,并根据生态环境的遥感探测机理,利用TM卫星遥感数据中的可见光、热红外、植被指数(NDVI)以及DEM数据,建立了基于BP神经网络的区域生态环境信息自动提取模型,形成了一种新的生态环境分类方法,其分类结果与实际情况完全一致。 相似文献
147.
148.
基于灰度形态学的高分辨率遥感影像预处理 总被引:6,自引:0,他引:6
提出了一种从高分辨率遥感影像中提取线性目标时影像预处理的方法。该方法基于灰度形态学的Top-Hat运算和灰度膨胀运算,用Top-Hat算子除去影像的噪声,再利用灰度膨胀增强影像目标和背景之间的对比度,使目标更易于识别。经过处理的遥感影像,能够更有效地提取影像的目标。 相似文献
149.
数学形态学着重于分析和处理图像的几何结构信息。根据这一原理,在图像分类预处理过程中,对各种地物区域的几何结构特点进行分析,构造相应的结构元素,然后对图像进行形态迭代分解法(IMD,Iterative Morphological Decompostion)变换。在变换结果中,地物区域的灰度信息进行了归一化处理,同时区域的几何结构特点和独立地物得到了有效保留。将多光谱图像的IMD变换结果进行分类实验的结果表明,该方法可以有效提高多光谱图像分类的精度和效率,具有较强的适用性。 相似文献
150.
GIS数据辅助下的线状目标自动提取 总被引:2,自引:0,他引:2
首先介绍了遥感影像中线状目标骨架自动提取的意义和研究现状,然后结合老的GIS数据,提出了一种算法来实现遥感影像中线状目标骨架的自动提取,算法主要包括影像预处理、GIS数据与影像的配准、骨架跟踪、编组连接与数据简化等步骤。最后又利用遥感影像和相应的GIS数据进行了实验,实验证明了算法的可行性和有效性。 相似文献