港珠澳大桥水下结构物的多手段探测

介绍了利用侧扫声纳、浅地层剖面仪和磁力仪开展港珠澳大桥水下结构物的探测方法和过程,并将探测的结果与调查收集的资料比较,分析水下结构物的分布情况,不同探测方法得出的结果也可以相互印证。     

无惩罚系数SVM高光谱影像分类算法研究

惩罚系数是支持向量机(SVM)机器学习中的一个重要参数,它的设置对分类结果有很大影响。但它没有规律可循,高光谱影像数据量大、数据复杂,为其选择合适的惩罚系数非常困难。提出无惩罚系数的SVM算法,利用最近点算法(NPA)计算二分类,对错分数据不设惩罚系数,而是对其重新构造凸集,计算最优超平面,迭代循环直到错分率达到所设的阈值为止。此算法简化了计算过程,降低了误分率。最后用AVIRIS高光谱影像进行实验,实验效果显示,本算法的分类精度和速度都得到很大提高。     

CBERS-02B星数据融合方法评价

CBERS—02B星(以下简称02B星)多光谱CCD数据与全色HR数据空间分辨率相差较大,给图像融合带来一定困难。在对IHS变换、主成分分析变换、Brovey 变换、GS变换等融合算法分析的基础上,利用02B星数据进行了融合试验。通过对试验结果的目视评价与定量分析发现,PC变换和GS变换方法融合图像纹理信息较清晰,光谱保真度较好。在GS变换融合中,可利用02B星CCD相机第5波段模拟GS变换的低分辨率输入,融合结果统计值优于PC变换。     

矢量图形与影像图像一体化实现

本文在阐述影像金字塔相关理论（构建方法、影像切割等）的基础上,采用VC2005编程实现了在同一GIS系统中进行矢量数据和栅格数据叠加显示的功能模块。该模块可确定是否加载影像,并根据当前矢量图显示范围自动加载不同分辨率的影像图。     

轮廓波变换在遥感目标图像检索中的应用

除具有纹理属性外,遥感图像中还包含大量的结构性边缘特征。如何有效捕捉这些特征中的信息进行检索,成为提高遥感图像检索效率的关键。依据Contourlet在离散域的多尺度几何分析的功能,提出一种利用Contourlet子带能量分布特性提取原始图像在多个尺度下的边缘方向信息进行检索的方法。针对Cont-ourlet变换响应不同特征方向能力的差别,采用正交补偿法加以改正,经过傅里叶算子的处理,从而实现旋转不变结构性边缘特征的检索。最后,在遥感目标图像上所作的实验证实了该算法的有效性。     

未知DEM下的机载SAR图像几何校正方法研究

针对机载环境复杂,不确定因素众多,与图像相对应的DEM不能精确获得等影响校正的不利因素,研究基于先验条件而不依赖DEM的机载SAR图像几何校正方法.从产生畸变的原理和校正过程的本质出发,将不同的几何校正理论在成像原理层面进行统一;在此基础上,分析精确校正所需要的条件,并提出当条件不能满足时的基于统计模型的几何校正方法;继而提出基于不同先验条件的校正方案决策模型.仿真实验及基于配准区域的保真度评价结果验证了所提方法的有效性.     

CBERS-02B星数据在“5·12”地震灾害监测中的应用——以唐家山堰塞湖动态监测为例

利用CBERS-02B星获取的多时相CCD数据,采用人机交互方式对唐家山堰塞湖进行水体信息提取,对湖泊面积变化进行统计分析,从而了解湖面的动态变化及发展趋势,为地质灾情评估与灾害防治提供了定量化依据。     

FY-3微波成像仪遥感图像地理定位方法研究

MWRI (MicroWave Radiation Imager) is one of the payloads on our next generation polar meteorological satellite FY-3. MWRI conically scans with a fixed incident angle on the earth surface. It is the first time for Chinese remote sensor to use this scan mode. In this work, we present a geolocation method for FY-3 MWRI’s remote sensing image based on its special scan geometry. The integrated coordinate systems and the specific relationships with these coordinate systems are defined. A spatial relationship model between the remote sensing data and the earth-based coordinate system is established. This method also includes an algorithm of satellite orbit computation, which is used to get the satellite’s instantaneous velocity vector from its position. This method has been applied to MWRI’s remote sensing image geolocation. The results show that the accuracy of this method can achieve 1 pixel. The 33 GCPs (Ground Control Points) which are in the regiones of FY-3 MWRI’s observation have been collected and used to analyze the precision of the geolocation. By statistical analysis, the error along-track is about 1.5km, and the error along-scan is about 3.0km. It is obvious that this method fulfills the requirement of precision for FY-3 MWRI whose space resolution exceeds 5km.     

山区遥感图像自动分类研究——以西南地区为例(英文)

In mountainous areas, it is the undulant terrain, various types of geomorphic and land use that make the remote sensing images great metamorphism. Moreover, due to the elevation, there are many areas covered with shadow, clouds and snow that make the images more inaccurate. As a result, it would be very difficult to carry out auto-classification of RS images in these areas. The study took Southwest China as the case study area and the TM images, SPOT images as the basic information sources assisted by the a...