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Table of Content

    25 June 2011, Volume 40 Issue 3
    The Research on High Dimensional Data Clustering Based on Improved Feature Transformation
    2011, 40(3):  269-275. 
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    The researches on similarity measure, feature transformation and the design of dimensionality reduction converter have been done in this paper, and the high dimensional data clustering algorithm is proposed. Firstly, gain the similarity matrix of high dimensional data with the similarity measure function HDsim designed in the paper, and translate it into distance matrix. Construct the graph of distance matrix through the nearest neighbor searching method and gain the distance matrix of the shortest path based on the algorithm Floyd. Then, translate the dimensionality reduction process into the optimization and design the fitness function, resolve this optimization problem with genetic algorithm. Finally, the reduced data is used for clustering analysis via k-means and the value pairs between the coordinates of high dimensional data and their reduced 2D coordinates are used for RBF neural network training, save the trained neural network. Determine the belongingness of new object based on the distance from the new object to each current clustering center through the trained neural network. It proves the validity of the high dimensional data clustering algorithm proposed in this paper through the clustering analysis of the data set iris and zoo in the machine learning database provided by UCI.

    学术论文
    Color Orthophoto Map Generation Based on Multi-direction and Multi-polarization SAR Data Fusion
    2011, 40(3):  276-282. 
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    Synthetic aperture radar is an effective earth observation technique for areas with frequent cloud and mist cover, rain and snow perennially. But in some complex terrain areas, such as west China, there are a lot of mountains and canyons. Because of large terrain relief and complex geomorphic types, the SAR images acquired from these areas present serious geometric distortions. For example, foreshortening, layover and shadow, are usually extremely severe. The radiometric distortion induced by topographic relief is also strong. These factors limit the application of SAR mapping. In order to cope with these shortcomings, a new method and technical flow based on multi-direction and multi-polarization SAR data fusion is proposed according to complex terrain and inherent characteristics of SAR images. And corresponding software module is developed based on an independently developed software system-SAR mapping workstation. This method fuses SAR images acquired from different looking directions, with different resolutions and multi-polarization to make color orthophoto map. Firstly, it uses the target decomposition to make color images based on the multi-polarization SAR data. The color images are ortho-rectified using the range-doppler model with sparse ground control points. And the radiometric distortions induced by topography relief of the color images are eliminated using high-precision DEM. Then the SAR data of high resolution and single polarization is merged with a multi-polarized SAR data with lower resolution and acquired from the same direction based on the IHS transformation. Finally a fusion method is proposed based on slope and aspect to fuse data with opposite viewing directions in order to compensate the information in layover and shadow areas. A data fusion test is carried out using TerraSAR-X data with 3m resolution and single polarization and fully polarized RadarSAT-2 data with 8m resolution in Hengduan Mountain to make the color orthophoto map. The experiment result proves that this method is effective and practical. At present, the proposed method, technical flow and software module has been widely used in the 1:50000 Scale Topographic Mapping Project in West China.
    Kalman Filter Phase Unwrapping Algorithm Based on Topographic Factors
    2011, 40(3):  283-288. 
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    Phase unwrapping is the key step in Digital Elevation Model extraction and Differential Interferometry of Interferometric Synthetic Aperture Radar (InSAR). When the terrain is steep or slope is larger, the unwrapping result is bad and causes error transmission using the existing Kalman Filter phase unwrapping algorithm. Considering this situation, this paper presents a Kalman Filter phase unwrapping algorithm based on topographic factors for InSAR. It can be implemented through the introduction of the input control variable associated with topographic factors to the state-space model of Kalman Filter. Owing to the fact that the interference fringes directly reflect the change of the terrain and local fringe frequency is closely related with the local terrain slope, we can use the local fringe frequency estimation as the input control variable. In the local frequency estimation, using two-dimensional Chirp-Z transform, we can quickly get better estimate of the results. In this paper, using simulated data and real InSAR data to do the experiment and compared with the conventional Kalman filter phase unwrapping algorithm, it can gain more reliable unwrapping result. It is verified that the proposed algorithm can effectively deal with the situation of steep terrain and larger slope.
    Research on Polarimetric SAR Image Speckle Reduction Using Kernel Independent Component Analysis
    2011, 40(3):  289-295. 
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    Speckle reduction is a very essential part during the process of the polarimetric synthetic aperture radar (POLSAR) image, but the traditional common methods have each defects. In order to improve the accuracy of polarimetric synthetic aperture radar image speckle reduction, a polarimetric SAR image speckle reduction method using kernel independent component analysis (KICA) is presented. This method uses the polarimetric information of three channels as its input data, obtains three independent components after KICA conversion, and takes the one with the smallest speckle index as the filtered results. Due to the introduction of kernel function, the information that can not be linearly separated using independent component analysis (ICA) algorithm achieves linearly separated in the kernel high-dimensional space. For the purpose of verifying the validity of the KICA method, the AIRSAR data of San Francisco area and the PISAR data of Japan’s Niigata region were tested. The efficiency was objectively evaluated by the speckle reduction index and the edge preservation index. And the experiment results show that the image edges are retained better and the speckles are removed more effectively with the method of KICA algorithm compared with the ICA algorithm.
    Investigation on Tree Height Retrieval with Polarimetric SAR Interferometry based on ESPRIT Algorithm
    TAN Lulu 2, 2
    2011, 40(3):  296-300. 
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    Tree height retrieval results making use of polarimetric interferometry SAR data based on ESPRIT algorithm is seriously biased because of the existence of depolarized components. In order to solve this problem, a modified inversion algorithm combining coherence optimization theory and its physical scattering mechanism is presented. Also, a new scattering vector called coherence optimized scattering vector is introduced to help understanding the algorithm. Finally, the proposed and traditional ESPRIT algorithm is applied to simulated L-Band PolInSAR data provided by ESA respectively, and the experiment results suggest the validity of the inversion algorithm.
    Classification for Beijing-1 Micro-Satellite’s Multispectral Image Based on Semi-Supervised Kernel FCM Algorithm
    2011, 40(3):  301-306. 
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    Aim at these problems of most of remote sensing image data don’t submit to gauss distribution, as well as remote sensing image classification exists the nonlinear, fuzzy and few labeled data, a semi-supervised kernel-based fuzzy C-means (SSKFCM) algorithm is proposed for classification of multispectral remote sensing image. First, the SSKFCM algorithm is presented by introducing simultaneously semi-supervised learning technique and kernel method into conventional fuzzy C-means (FCM) algorithm. Then, the experiments of the SSKFCM algorithm and a few conventional classification methods are implemented to test the properties of classification results for Beijing-1 micro-satellite’s multispectral image. Finally, the classification performance is estimated by corresponding indexes. The results show that the SSKFCM algorithm improves significantly classification accuracy compared with conventional classifiers (K-means algorithm and maximum likelihood algorithm). Also, it outperforms the FCM algorithm, the KFCM algorithm and the SSFCM algorithm.
    A Sub-pixel Mapping Algorithm based on BP Neural Network with Spatial Autocorrelation Function for Remote Sensing
    2011, 40(3):  307-311. 
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    Sub-pixel mapping is an effective method to obtain the distribution of land cover in mixed pixels. This paper proposes a sub-pixel mapping algorithm based on an improved BP neural network with Moran' I, which is a kind of spatial autocorrelation function, to constrain the distribution of sub-pixels to satisfy the concept of spatial dependence better than conventional BP neural network methods. The experimental results indicate that the proposed mapping algorithm outperforms the original BPNN model in terms of both quantitative measurements and visual evaluation.
    Linear Feature Detection form High-resolution Remotely Sensed Imagery in Frequency Domain
    2011, 40(3):  312-317. 
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    Linear feature in remote sense image has great geonomy and geometry significance, linear feature ascertaining and extracting in high resolution remote sense image is the basis and key premise of high-level image project such as image analyzing and understanding. In this paper, we discussed a method based on direction and frequency selected through designing frequency domain filtering for the remote sense image linear feature automatic detection and recognition, first owed to Fourier transformation method transform the image into frequency domain, and analyzed the relations between linearity characteristic and its spectral line, also the relations between the linearity characteristic and image frequency, at the bases of the direction and frequency selected above the Gabor wave filter for image linearity feature extracting was constructed. The relevant extract experiments was tested with Quickbird image, the experiments result indicates that the linearity characteristic being extracted in this method is fairly good, it provided a reference for high-resolution remotely sensed imagery linear feature extracting, and also provided a new ways for feature extract in frequency domain use of high-resolution satellite imagery based on accurately frequency spectrum analysis.
    Matching Multi-sensor Images Based on Gradient Radius Angle Pyramid Histogram
    2011, 40(3):  318-325. 
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    Traditional algorithm for matching multi-sensor images are mostly based on region information, which is sensitive to image rotation. This paper presents a new rotate-invariant feature named Gradient Radius Angle Pyramid Histogram(GRAPH), that can be used in matching multi-sensor images of arbitrary angle. We calculate the Gradient Radius Angle(GRA) based on normalized gradient vector and radius direction vector. The GRA is invariant to image rotation and robust to image noise, and illumination change. To get sparse description, we use circle region histogram to represent the statistic distribution of GRA. Pyramid Histogram(PH) is utilized to replace simple histogram for better distinctive capability. Experimental results show that the GRAPH feature can distinguish images of different scenes and accommodates to image rotation. Multi-sensor images are reliably matched based on GRAPH feature.
    Research on Nephogram Nonrigid Registration Method Based on B-Spline
    2011, 40(3):  326-331. 
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    Serial images obtained by meteorological satellite have both rigid and nonrigid deformations. Due to this characteristic, a hierarchical transformation model of the motion based on B-spline is introduced. The global rigid deformation of the image is mainly caused by the position changes of the sensor, and it includes rotation and shift. Cloud’s distortion results in the local nonrigid deformation. The global motion of the image is modeled by an affine transformation which carries out the rigid registration. While the local image deformation is described by an improved free-form deformation (FFD) model based on B-spline. The algorithm has been applied to the fully automated registration system of nephograms, and the results clearly indicate that the approach we proposed can not only achieve sub-pixel precision, but also decrease the runtime of the process.
    Full-automatic Method for Coastal Water Information Extraction from Remote Sensing Image
    2011, 40(3):  332-337. 
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    A new water-extraction method, which focuses on the characteristics of the Coastal water, was proposed in this paper. The method could extract water full-automatically, by using the scale transformation from pixel to object and from global to local, using the spectral features, special features, statistic features and uncertainty of Coastal water remote sensing information, and using the combination of geo-knowledge and data mining technology. Experimental result indicates that, the method could extract water in various types of coastal zones with better completeness, better continuity and higher accuracy than classic methods such as supervised classification and threshold segmentation.
    Transformation Method of Exterior Orientation Angular Elements Obtained via a Position and Orientation System under Gauss-Kruger Projection Coordinate System
    2011, 40(3):  338-344. 
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    Data obtained by airborne position and orientation system (POS) are in WGS 84 global geocentric reference frame, the national coordinate reference systems for topographic mapping in China are generally Gauss-Kruger projection coordinate system. Therefore, data obtained by a POS must be transformed to national coordinate system. Owing to the effects of earth curvature and meridian deviation, there are some errors in the process of angle transformation from roll, pitch and heading obtained directly by a POS to the attitude angles of images needed in photogrammetry. On the basis of effect theories of earth curvature and meridian deviation on exterior orientation angular elements of images, the method using a compensation matrix to correct the transformation errors from attitude angles obtained by the POS to exterior orientation angular elements of images is proposed in this paper. Moreover, the rigorous formula of the compensation matrix is deduced. Two sets of actual data obtained by POS AV 510 which are different in scale and terrain are selected and used to perform experiments. The empirical results not only indicate that the compensation matrix proposed in this paper is correct and practical, but also show that transformation accuracy of exterior orientation angular elements obtained by the POS based on compensation matrix is relevant to the choice of vertical axis (a projection of central meridian) of Gauss-Kruger projection coordinate system; the proper vertical axis should be the Gauss-Kruger projection of the central meridian of projection zone which survey area locates. However, the transformation accuracy of exterior orientation angular elements is irrelevant to the choice of origin of coordinate system; it is appropriate that the origin of coordinate system locates at the center point of the survey area. Moreover, transformation accuracy of exterior orientation angular elements computed based on the compensation matrix deduced in this paper is higher than that obtained by the POS.
    Dynamic Calibration of Exterior Orientations for Vehicle GPS/IMU/LS Laser Imaging System
    2011, 40(3):  345-350. 
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    This paper proposed a calibration method with small rotation-angle corrections for the exterior orientations of vehicle laser imaging system. In the vehicle laser imaging system, Mobile Surveying & Mapping Platform system (MSMP), integrated GPS with both IMU (Inertial Measurement Unit) and LS (Laser Scanner), the method uses six small rotation-angle parameters and six small translation parameters to correct the parameters of traditional models. The experiments show that the new method efficiently corrected installation errors and temporal synchronism errors in the system.
    The Research of Collinearity Theory for Two-media Photogrammetry
    2011, 40(3):  351-358. 
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    This article deals with optical laws that must be considered in camera lens system. With a brief introduction of the pin-hole model, it describes the view that the projection center of camera is the equivalent of two nodal points. This paper also presents a different view from the traditional standpoint of two-media photogrammetry, illustrating the collinearity relation for two-media photogrammetry owe to the shift of datum marks. With the base of the collinearity theory, it concludes that the principal length in two-media photogrammetry is approximately equal to the one in one-media photogrammetry multiplying with the refractive index of the object space in two-media photogrammetry. The experiment on one antenna shows that high levels of accuracy can be achieved.
    A Method for Interpolating Digital Depth Model Considering Uncertainty
    2011, 40(3):  359-365. 
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    The digital depth model(DDM) is the core and foundation in the process and applications of chart depths. A method for interpolating DDM considering uncertainty is proposed. The uncertainty of the soundings deriving from the different data sources is calculated, the interpolation model by using the uncertainty in weighting for the soundings is constructed, and the uncertainty of the interpolated depth node is estimated. Experimental results demonstrate that the proposed method has improved the quality of DDM and can estimate the uncertainty of the interpolated depth node.
    A spatio-temporal simulation and planning model for farmland conversion based on multi-agent systems
    2011, 40(3):  366-372. 
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    Although current land-use and land-cover change(LUCC) and urban growth simulation models can simulate and predict spatial pattern of farmland, it’s not applicable for the interpretation of interaction between all kinds of agents during the process of farmland conversion and reasonable spatio-temporal simulation and planning of farmland conversion. Following the principles of maximal spatial and temporal planning efficiency as well as sustainable development, a spatio-temporal simulation and planning model for farmland conversion is developed with integration of multi-agent system and resource economics theory. The proposed model, which consists of some related components, i.e., external environment, multi-agent system, decision-making framework, can explicitly represent agents’ spatio-temporal decision-making behaviors and rules during the process of farmland conversion, simulate the developmental tendency of farmland conversion under different planning guidelines and provide auxiliary decision-making support for farmland resources planning. The proposed model is applied to the simulation and planning of farmland conversion in the core areas of Changsha, Zhuzhou, Xiangttan city cluster in 2006-2020, which is the national comprehensive reforms test areas of building resource-saving and environment-friendliness society in China. The simulation results and the analysis of ecosystem service loss under different planning guidelines show that the model is able to provide a spatial exploratory tool for spatio-temporal planning of farmland conversion.
    Topographic cartographic model based on algebraic structure
    2011, 40(3):  373-378. 
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    With an accumulation of abundant geo-information, production of high quality maps for presenting the geo-information challenges the capacity of GIS. Geo-database-driven cartography emerging as an effective means to produce maps from geo-databases, have not been scrutinized in a systematic way, especially in terms of modeling the process of map-making. A cartographic model being put forward in this paper characterizes the process of map-making by a transformation from geographical space to map space based on an algebra structure, and provides with a theoretical foundation and operational guideline for this merging technology. According to cartographic presentations of geo-data in topographic maps, geo-information is abstracted into two elements: geo-features and spatial relationships between the features, and further structured in form of algebra into two algebraic spaces; Geo-Feature Space in a geo-databases world and Map-Feature Space in a map world respectively. The spatial relationships in Geo-Feature Space are modeled by Euclidean space and the spatial relationships in Map-Feature Space are calibrated by the visual cognitive mechanism. The cartographic model is built up by transforming geo-features into map-features which is restrained by the consistent spatial relationships in the two spaces. By defining an equivalent-kernel transform among symbol cells, map symbolization based on feature classes is extended into that based on feature instances, fitting cartographic representations being both specified and universalized. With defining the displacement transform for geo-features, the process of map-making proceeds more smoothly, reducing being intervened to a large extent. This model through the two transforms, articulates the key issue for automating map-making and reveals the mechanism of the transformation of geo-information from geo-databases to map representation, providing a guideline for better design of functionality of GIS.
    Cooperative Generalization Method of Contour Cluster and River Network Based on Constrained D-TIN
    2011, 40(3):  379-385. 
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    Against the defect of the traditional cartographic generalization strategy which processes the map features separately hence often causes spatial and semantic conflicts between different geographical features on the map, we take into account the spatial relevance between terrain and rivers to introduce a cooperative generalization method which integrates the contour clusters with the river networks. Using the spatial proximity relations between the vertexes of the above-mentioned two map features in the constrained Delaunay TIN and via extracting and organizing the bends of valley contours, we construct the cooperative relation between the two features. On this basis, we divide contour clusters into different segment types according to the local topography, and then perform the corresponding simplification under the subset of the river networks given by a hierarchical selection method, so as to keep the position of every river of the networks to the bottom of the valleys. The experiment result proves that this cooperative method can effectively avoid the conflicts between the contour clusters and the river networks, and helps to improve the intelligence level of cartographic generalization.
    Computation of spatial position parameters of magnetic object with improved Euler approach
    2011, 40(3):  386-392. 
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    Considering the deficiency of conventional Euler approach in magnetic detection at present, the combining influence of geomagnetism and adjacent bodies’ anomaly is assumed as linear variation. The non-linear problem of Euler equation has been figured out utilizing multivariate linear regression with unprescribed structural index. In quality control scheme, filtering technique of Euler solutions is presented based on the relationship between structural index and object depth. Adopting the distance acceptance criteria, the dispersed Euler solutions are isolated to different clusters firstly. The modifying stage combines the already focused solutions by the previous clustering in more general clusters and makes a fusion of the clusters whose horizontal centers of gravity have no remarkable difference using t-Student distribution test. Since the clusters with small number of points are statistically not significant, we apply a filter method that eliminates the clusters with less than a given number of points. Then, the mean values are corresponding to the position of magnetic objects. The effectiveness of the suggested techniques has been illustrated by simulated sphere/ cuboid examples and real magnetic data from a collection of environmental ferro-metallic objects. The conclusion shows that Euler approach, provided by relative threshold parameters, becomes a fully automatic interpretation approach, and the calculated horizontal position together with depth has very high precision. However, the noise influence to depth’s result is more serious than it to horizontal position.
    Evaluating on the Theoretical Accuracy of Error Distribution of Vanishing Points
    2011, 40(3):  393-396. 
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    The related researches of vanishing point have been focusing on its automatic detection and camera calibration for a long time, however there were few researches on its error distribution. Aiming at the closing error issue of lines intersection and the error distribution of vanishing points, we have made in-depth discussions. How to set initial weights for the adjustment solution of single image vanishing points is presented. Furthermore, we propose solving and estimating error distribution of vanishing points based on iteration method with variable weights, co-factor matrix and error ellipse theory. Not only do experimental results reveal the law of error distribution of vanishing points, but also pave the way for the theory and practicability of 3D reconstruction based on vanishing points.
    Multipurpose Watermarking Algorithm for Digital Raster Map Based on Wavelet Transformation
    2011, 40(3):  397-400. 
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    A compound watermarking algorithm for digital raster map is proposed based on wavelet transformation in this paper. The basic idea is to embed the robust watermark and the fragile watermark into different frequency blocks of the digital raster map based on the features of digital raster map with higher luminance and greater sensual capability than image data. The robust watermark is adaptively embedded into low frequency section to protect the copyright of the data. The fragile watermark is embedded into high frequency section by the dithered modulation technique to achieve the goal of content authentication according to the characteristics of human visual systems. The experiments show that the proposed algorithm can attest content integrity for digital raster map, and is robust against various malicious attacks such as JPEG compression, sharpening, cutting etc.
    博士论文摘要
    Error Compensation and Extension of Adaptive Filtering Theory in GNSS/INS Integrated Navigation
    2011, 40(3):  401-401. 
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    Study on Spatial Location Identification and Spatial Object Identification based on Subdivision Encoding
    GUAN Li
    2011, 40(3):  402-402. 
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