Error analysis of satellite attitude determination using a vision-based approach     

《ISPRS Journal of Photogrammetry and Remote Sensing》2013

Improvements in communication and processing technologies have opened the doors to exploit on-board cameras to compute objects’ spatial attitude using only the visual information from sequences of remote sensed images. The strategies and the algorithmic approach used to extract such information affect the estimation accuracy of the three-axis orientation of the object.This work presents a method for analyzing the most relevant error sources, including numerical ones, possible drift effects and their influence on the overall accuracy, referring to vision-based approaches. The method in particular focuses on the analysis of the image registration algorithm, carried out through on-purpose simulations. The overall accuracy has been assessed on a challenging case study, for which accuracy represents the fundamental requirement. In particular, attitude determination has been analyzed for small satellites, by comparing theoretical findings to metric results from simulations on realistic ground-truth data. Significant laboratory experiments, using a numerical control unit, have further confirmed the outcome.We believe that our analysis approach, as well as our findings in terms of error characterization, can be useful at proof-of-concept design and planning levels, since they emphasize the main sources of error for visual based approaches employed for satellite attitude estimation. Nevertheless, the approach we present is also of general interest for all the affine applicative domains which require an accurate estimation of three-dimensional orientation parameters (i.e., robotics, airborne stabilization).  相似文献   

Texture augmented detection of macrophyte species using decision trees     

《ISPRS Journal of Photogrammetry and Remote Sensing》2013

Image classification using multispectral sensors has shown good performance in detecting macrophytes at the species level. However, species level classification often does not utilize the texture information provided by high resolution images. This study investigated whether image texture provides useful vector(s) for the discrimination of monospecific stands of three floating macrophyte species in Quickbird imagery of the South Nation River. Semivariograms indicated that window sizes of 5 × 5 and 13 × 13 pixels were the most appropriate spatial scales for calculation of the grey level co-occurrence matrix and subsequent texture attributes from the multispectral and panchromatic bands. Of the 214 investigated vectors (13 Haralick texture attributes * 15 bands + 9 spectral bands + 10 transformations/indices), feature selection determined which combination of spectral and textural vectors had the greatest class separability based on the Mann–Whitney U-test and Jefferies–Matusita distance. While multispectral red and near infrared (NIR) performed satisfactorily, the addition of panchromatic-dissimilarity slightly improved class separability and the accuracy of a decision tree classifier (Kappa: red/NIR/panchromatic-dissimilarity – 93.2% versus red/NIR – 90.4%). Class separability improved by incorporating a second texture attribute, but resulted in a decrease in classification accuracy. The results suggest that incorporating image texture may be beneficial for separating stands with high spatial heterogeneity. However, the benefits may be limited and must be weighed against the increased complexity of the classifier.  相似文献   

基于波段子集的独立分量分析的特征提取的高光谱遥感影像分类     

郭学兰;杨敏华;毛军;周秋琳 《东北测绘》2013,(4):144-146,149+152

针对高光谱影像数据具有波段众多、数据量较大的特点,本文提出了一种基于波段子集的独立分量分析(ICA)特征提取的高光谱遥感影像分类的新方法。以北京昌平小汤山地区的高光谱影像为例,根据高光谱遥感影像的相邻波段的相关性进行子空间划分,在各个波段子集上采用ICA算法进行特征提取,将各个子空间提取的特征合并组成特征向量,采用支持向量机(SVM)分类器进行分类。结果表明:该方法分类精度最佳(分类精度89.04%,Kappa系数0.8605,明显优于其它特征提取方法的SVM分类,有效地提高了高光谱数据的分类精度。  相似文献   

低空遥感数字影像的点特征提取算子的比较     

王利勇  王慧  李鹏程  吴翰书 《测绘科学》2011,36(1):121-124

低空遥感是遥感影像数据获取的重要手段之一,点特征是最常用的影像特征,目前存在多种点特征提取算法.本文根据低空遥感数字影像的特点和实际应用中的要求,利用探测速度、适应性、提取效能三个特征提取算法的比较标准对常用的点特征提取算子进行了比较.为针对不同特点的低空遥感数字影像,选择某点特征提取算法提供依据.  相似文献   

Matlab对基于二进制-XML混合格式的SMOS盐度数据的提取方法与实现     

陈建  张韧  王辉赞  安玉柱 《海洋通报》2011,30(6):692-696

基于二进制-XML混合文件格式的SMOS盐度数据的处理和延伸应用仍处于初级阶段,其前提是对SMOS数据的提取.本文详细介绍了SMOS的文件格式和利用Matlab对SMOS文件进行读写操作的方法,在此基础上给出了提取SMOS数据的流程图和实例,为SMOS数据产品的开发等下了基础.  相似文献   

短期暴雨的前期特征和预报实践   总被引：3，自引：0，他引：3  

姜海泉 《广东气象》2001,(2):1-4

打破季节和月份的限制，将所有的暴雨作为研究对象，运用自组织理论总结归纳出一套自成体系的统一的关于短期暴雨预报的前期环流特征和判据。在预报业务上，作者成功地建立三个精确到点的高质量的短期暴雨预报方法。  相似文献   

山西岩溶水强径流带的成因类型及其水文地质特征   总被引：5，自引：4，他引：1  

裴捍华  杨亲民  郭振中  黄卫星 《中国岩溶》2003,22(3):219-224

根据成因特征,将山西岩溶水强径流带分为五种类型: 接触带型、河谷型、构造带型、向斜谷地型和复合型。通过野外调查及对大量实测资料的分析研究,揭示出山西岩溶水强径流带的主要发育与分布特征: 岩溶水强径流带呈网状分布;发育深度50～300m;地下水面呈槽谷型,水力坡度一般在0. 6‰～2. 8‰之间。岩溶强径流带水量丰富,单井出水量大于1000m3 /d,是建立岩溶水水源地的理想场所。   相似文献   

利用RADARSAT-1数据提取海水养殖区面积   总被引：5，自引：0，他引：5  

樊建勇  黄海军  樊辉  郜昂 《海洋科学》2005,29(10):44-47

利用2001年胶州湾RADARSAT-1数据,探讨了SAR影像在海水养殖面积监测方面的可行性。选择适当成像参数、天气与海况等环境条件下成像的遥感数据,进行SAR影像的几何校正、图像增强等图像处理,提取养殖区面积信息。选取胶州湾西北部大沽河口至红岛间的海域作为实验区,对处理后的影像进行养殖区面积的提取,结合常规调查数据对该海域养殖类型变迁分析,结果表明1999到2001年间有4.634×106m2海域由底播养殖区转变成水面养殖区。  相似文献   

基于小波变换的雷达与光学影像匹配算法研究   总被引：10，自引：4，他引：6  

陈鹰  叶勤  钟志勇 《测绘学报》2000,29(3):245-249

分析了实孔径雷达与ＣＣＤ传感器影像不同的成像特点,讨论了采用小波变换进行边缘检测、影像分解与重建、实现分层匹配的方法;同时,提出了多种匹配算法模式。经过试验,取得了良好的结果。  相似文献   

赤道东太平洋SST强增温过程特征分析     

林玉英  战淑芸 《海洋预报》2000,17(1):30-37

本文利用太平洋海温距平场资料,对１９８６年以来发生的厄尔尼诺过程的开始时间、发展过程及强度等方面进行了分析。并与历史上的厄尔尼诺过程进行比较,结果表明,９０年代是厄尔尼诺事件的多发期,在１９９１￣９８年的８年中,间连续发生四次厄经诺事件,其中１９９７￣９８年的厄尔尼诺,成为有历史记录以来最强的一次过程。  相似文献