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    25 April 2018, Volume 0 Issue 4
    A Real Time Regional Zenith Troposphere Delay Model and Its Application in PPP
    SONG Jia, LI Min, ZHAO Qile, DAI Zhiqiang
    2018, 0(4):  1-5,15.  doi:10.13474/j.cnki.11-2246.2018.0100
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    The real time regional zenith troposphere delay model is introduced by using the inverse distance weighted interpolation method.We assess its influence on the accuracy and convergence time of precise point positioning statistically.The result shows that the ZTD estimation and model calculation can achieve the same horizontal accuracy,but the model corrected PPP improves the vertical accuracy by 5 cm.Furthermore,the convergence time can be reduced obviously with model correction.Validation shows that the real time regional zenith tropospheric delay model introduced in this paper can effectively speed up the convergence of PPP and improve the positioning accuracy.

    Noise Analysis of the Coordinate Time Series of the Large-scale GPS Network with Consideration of Common Mode Error
    WANG Jian, XU An'an, ZHOU Boye
    2018, 0(4):  6-9,56.  doi:10.13474/j.cnki.11-2246.2018.0101
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    Noise analysis has an important influence on GPS time series analysis.However,there are few studies on common mode error of large-scale GPS network with long time span.In this paper,nine GPS stations with average baseline length of more than 2000 km are selected.Time span from 2006 to 2014,and the principal component analysis method was used to remove the common mode error from the coordinate time series,and the time series before and after filtering was analyzed by the method of maximum likelihood estimation.The results show that the noise model of wide area GPS network in Europe is diverse,and each component has different noise characteristics,mainly for white noise + flicker noise,white noise + power law noise,a small number of stations contains random walk noise in N and E direction.After spatial filtering,the optimal noise model of some stations is changed,but is still white noise+flicker noise,white noise+power law noise.The effect of filtering on the velocity field in N and E direction is 0.2 mm/a,and the velocity field in U direction is 0.5 mm/a.

    A Probabilistic Framework for the Segmentation of Remote Sensing Imagery
    ZHAO Zhan, YAN Li, XIA Wang
    2018, 0(4):  10-15.  doi:10.13474/j.cnki.11-2246.2018.0102
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    Image segmentation method based on region growing suffers the problem of selecting appropriate growing seeds and segmentation parameters.A segmentation method based on a novel kind of region-merging probability measure is proposed to solve the problem in this paper.First,an initial segmentation is achieved by marker-based watershed transformation and simple region merging.Statistic,context and shape information can be calculated from the initial segmentation regions.Then a scale-independent merging probability of neighboring regions is calculated by the information based on Bayesian criterion,which is integrated into sequential region merging procedure.It is easier to determine a threshold value for the new probability measure because of its intuitive meaning.And multi-scale objects can be simultaneously segmented in once segmentation,since the probability is independent of scale.Experiment shows a good performance of the method by visual and quantitative analysis and compared with multi-resolution segmentation results of eCognition.

    A Method for Right Angle Building Extracting and Mapping Based on MBR Constraints in High Resolution Optical Image
    LI Baishou, LI Lingzhi, ZHANG Qiang
    2018, 0(4):  16-22.  doi:10.13474/j.cnki.11-2246.2018.0103
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    Aiming at the problem of building extraction and mapping in high spatial resolution remote sensing images,a method based on MBR constraints is proposed.Firstly,this paper extracts the building from the image by using the multi-scale segmentation method and CART decision tree classification technology. Secondly,this paper extracts the rough contour of the building by using Candy operator,and expresses as point set for calculating building MBR,piecewise fitting and optimization the contour of buildings.Finally,this paper through the point direction decision maker seeks building's angular points and realizes building's mapping.After calculating building's area and perimeter,we can ensure that perimeter relative accuracy is 93.3%,area relative accuracy is 96.1%.The presented method can effectively improve the precision of buildings mapping.

    Analysis of Geo-positioning Simulation of GF-4 Satellite Images
    HAN Jie, XIE Yong
    2018, 0(4):  23-27.  doi:10.13474/j.cnki.11-2246.2018.0104
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    Through integrating the stationary orbit, high time resolution and area-array image characteristics of GF-4 satellite, building the rigorous sensor model, this paper realizes the geo-positioning simulation of GF-4 satellite. After analyzing the initial geometric simulation results, the geometric exterior calibration model is proposed. Then our research uses on-orbit real images and SRTM DEM to fulfill the geometric exterior calibration of the rigorous sensor model and discusses the influence of simulation control points (SCPs) distribution on camera angular systematic errors. The experiment results show the geometric simulation model can effectively simulate the geo-positioning errors of the on-orbit real GF-4 image after geometric exterior calibration.

    Remote Sensing Image Denoising Based on Improved Wavelet Threshold Algorithm
    CHEN Zhu'an, HU Zhifeng
    2018, 0(4):  28-31.  doi:10.13474/j.cnki.11-2246.2018.0105
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    Based on the research of wavelet threshold denoising method in the literature, an improved method of wavelet threshold denoising is proposed to improve and improve the processing capability and feasibility of wavelet threshold denoising. Combining some of the existing wavelet threshold denoising functions. The threshold function adds a valid adjustment factor to control the variable function. This function not only preserves the corresponding advantages of traditional wavelet hard threshold and soft threshold, but also improves the corresponding precision index. Using this function, threshold denoising not only improves greatly in classical images, but also improves the accuracy of noise detection in remote sensing images. The method evaluates the image by denoising after denoising evaluation mean square error (MSE), peak signal to noise ratio (PSNR), signal to noise ratio (SNR), and root mean square error (RMSE). The improved threshold function method has obviously improved the post-treatment evaluation index for the image.

    A Real-time Unmanned Aerial Vehicle Localization Method Based on Multi-view Stereo Vision
    WANG Chen, ZHENG Shunyi, ZHU Fengbo, GUI Li
    2018, 0(4):  32-35,82.  doi:10.13474/j.cnki.11-2246.2018.0106
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    In this paper,the author proposes a real-time unmanned aerial vehicle auto localization method based on multi-view stereo vision.Firstly,cameras are divided into several groups,and each group is connected with a computer to construct a local area network.Then,interior and exterior elements as well as the lens distortion parameters are measured.Next,images are captured simultaneously and the unmanned aerial vehicle is detected and located automatically by background difference and forward intersection.In order to verify this method,an unmanned aerial vehicle localization system is designed and implemented.The experimental results show that the method is feasible and effective and the expected accuracy is reached.

    Panchromatic Remote Sensing Image Classification Combining Maximum Likelihood Algorithm and Polya Urn Model
    LI Jie, LI Yu, WANG Yu, ZHAO Quanhua
    2018, 0(4):  36-43,49.  doi:10.13474/j.cnki.11-2246.2018.0107
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    Maximum likelihood (ML) algorithm is a widely used supervised method for remote sensing images classification.In ML algorithm,samples selections need to be extremely accurate,which also reduce the algorithmic efficiency.Therefore,a new method combined ML algorithm and Polya urn model to achieve panchromatic remote sensing images classification is presented.First,ML algorithm is used to calculate subordination probabilities of pixels.The numbers of balls of different colors are calculated by these probabilities,and the urn model of the image can be initialized.Urns' compositions are iteratively updated by the random sampling process of Polya urn model.The balls of the neighborhood are also combined to determine the next state of the urn.Finally,by steadying the quantity proportions of balls the final classification is achieved.The proposed method could classify images more precisely,and there is no request of samples selections;random selections of samples are practicable,which make the classification process simple.The results obtained on both synthesized and real remote sensing images show that the proposed method works well and is very promising.

    Extracting Water Information from OLI Remote Sensing Images Based on City Water Index and Fractal Geometry
    YANG Ji, HAN Liusheng, CHEN Shuisen, LI Yong
    2018, 0(4):  44-49.  doi:10.13474/j.cnki.11-2246.2018.0108
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    In the remote sensing images,roads,buildings and shadows are difficult to distinguish from severely polluted urban water bodies.And the extracting results from remote sensing images are not continuous and exists some spots.Aimed at these problems,this paper based on the 2016 and 2017 OLI remote sensing images,city water index (CWI) method is used.The fractal geometry algorithm and the shape area are used to automatic extract the water information in urban complex environment.The results are compared with single channel algorithm,modified normal difference water index (MNDWI) algorithm,support vector machine method (SVM) and spectral angle method.The results shows that there are a large number of spots in the SVM algorithm,followed by the MNDWI water body index algorithm.The spectrum angle algorithm and the single-channel algorithm are with fewer spots,but the water extraction results are discontinuous and part of the channel leakage.The algorithm proposed in this paper can continuously and accurately extract urban water bodies,and can also overcome the influence of mountain shadows,roads and buildings.Compared with other methods,this method is greatly improved.The results can provide basic data support for water resources investigation,flood disaster prediction and assessment,water conservancy planning and environmental monitoring.

    Using Principal Component Analysis and Geographic Weighted Regression Methods to Analyze AOD Data
    LI Guangchao, LI Ruren, LU Yueming, ZHAO Yangyang, YU Bo
    2018, 0(4):  50-56.  doi:10.13474/j.cnki.11-2246.2018.0109
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    To address the issue of geographical weighted regression model (GWR) for prediction,which more input variables lead to high computational complexity and less input variables induced lower predictive accuracy,a regression method based on geographical weighted principal component analysis (PCA-GWR) was proposed in this paper.It is used to predict the accuracy of prediction,which is based on principal component analysis (PCA).Firstly,the collinearity of the aerosol optical depth (AOD) influencing factors was tested by this method.Then,some related variables of influencing AOD values were processed by nonlinear principal component analysis,which eliminates the correlation variables.Finally,the nonlinear principal component analysis was used to obtain several comprehensive indexes,and the AOD value was analyzed and predicted by the geography weighted regression model.In order to verify the effectiveness of the method,the data of AOD,elevation,wind speed,air temperature,humidity,air pressure,slope and aspect of Beijing-Tianjin-Hebei area were collected,and it selected the factors by Pearson correlation coefficient method which were in high correlation with AOD concentration as the input variables of the conventional GWR model,compared with this method under the condition of same number of variables.The results show that the nonlinear principal component analysis method can effectively solve the collinearity between variables after preprocessing the relevant variables,and can retain the main information of the original influencing factors,and improve the efficiency of the calculation.Moreover,The MAE,RMSE,AIC and R2(goodness of fit) of this method are better than that of the conventional GWR model.

    An Automatic Approach for Remote Sensing Classification Supported by Sample Transfer
    LIN Cong, LI Erzhu, DU Peijun
    2018, 0(4):  57-62.  doi:10.13474/j.cnki.11-2246.2018.0110
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    This paper proposes a novel automatic classification approach to acquire land cover maps by classifying remote sensing images in the time series.Different from other sample collection methods,the proposed method tries to define a precise training set for target domain automatically by transfer learning.This method is proposed for Landsat TM images.This is done by change detection method and spectral curve shape vector.Firstly,the unchanged labels are located by change vector analysis.Then the prior class knowledge from source domain is transferred to the target images,taking advantage of the already available knowledge on the land cover products related to source images.Finally,the target image is classified by support vector machine.The result shows that the approach is effective in automatically obtaining land-cover classification maps.

    The Method of Indoor Positioning Based on Similarity Computation of Image Gray Histogram
    WANG Yongkang, WANG Yunjia, BI Jingxue, CAO Hongji
    2018, 0(4):  63-67.  doi:10.13474/j.cnki.11-2246.2018.0111
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    In recent years,visual positioning is widely used in indoor positioning and navigation because of its high positioning accuracy.However,we can't achieve high-precision positioning in many scenes with visual positioning algorithms due to complex indoor environment,and most of the visual positioning algorithms are not suitable for smartphones for its' high time and computational complexity.In order to realize the accurate and efficient positioning with smartphones,a method based on similarity computation of gray histogram is proposed.The method is divided into two stages:the offline stage and the online stage.In the offline stage,we acquire the image in the grid points of the known coordinates with the smartphone,and then the gray histogram of the image is extracted to establish the image gray histogram image feature database;In the online stage,the image is collected and gray histogram is extracted on test point by the smartphone,and then calculate the similarity between it and the image feature database.The grid of similarity and maximum is selected as the approximate position,the similarity is used as the weight,and the exact location is obtained by weighted mean method.Compare the proposed method with the KNN algorithm,the experimental result shows that the average positioning error is less than 0.3 m,average point positioning accuracy of this method is better than that of KNN algorithm,and compared to the KNN algorithm,the positioning accuracy is improved by 40.7%,and the computing time is better than 1.7 s.

    Automatic Break Line Extraction from Airborne LiDAR Point Cloud Using Topographic Openness
    ZHANG Liang, ZHANG Fan, JIANG Xiaoqi, ZHOU Jiawen, WANG Jiedong
    2018, 0(4):  68-72.  doi:10.13474/j.cnki.11-2246.2018.0112
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    In order to produce high quality digital elevation model (DEM) based on airborne lidar (LiDAR) point cloud,break lines need to be used as constraints.Aiming at the fact that error rate of break line extraction is relatively high because of existing algorithms only consider the local variation of the earth's surface,topographic openness,starting from the manual interpretation point of view,is applied as a new operator to extract breaklines.Firstly,the original ground points are sampled into the distance images.And then the main structure changes of the earth surface are extracted by topographic openness.Finally,the seed points of the break lines are extracted by morphological operators and edge extraction operators,and the vector of the broken lines is tracked.The experimental results show that the algorithm can quickly extract complete break lines without manual intervention.

    Feature Extraction of Building Point Cloud Based on Moving-least Squares Vector Estimation
    PEI Shuyu, DU Ning, WANG Li, ZHANG Chunkang, LIU Jigeng, XU Guangyu
    2018, 0(4):  73-77.  doi:10.13474/j.cnki.11-2246.2018.0113
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    The feature extraction quality and accuracy of the fine modeling building plays an important role in the feature information extraction of buildings clearly and accurately.The traditional vector estimation method is affected by noise,and exists some misjudgment problem,this paper proposed a feature extraction method of the point cloud mobile minimum two multiplication of buildings based on vector estimation.This method firstly uses the moving least squares method for estimation of normal vector,then the mean K neighborhood method as a significant index vector included angle point feature identification,finally the extracted feature points set by resampling,to eliminate redundant information.The experimental results show that the estimation of point cloud normal is more accurate and robust by moving least square method,thus effectively improve the accuracy and reliability of the building point cloud feature extraction,the feature point set resampling can delete the redundant feature point,the feature line extraction is more concise,clear and complete.

    Design and Implementation of Bridge Vibration Monitoring Radar
    SHAO Zelong, GAO Zhuoyan, ZHANG Xiangkun
    2018, 0(4):  78-82.  doi:10.13474/j.cnki.11-2246.2018.0114
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    Faced with the problem of common bridge vibration detection methods,a new radar system was designed using linear frequency modulation continuous wave signal and interference measurement technology to measure the bridge vibration indirectly.It avoided problems such as complex detection process,high cost,low precision and low efficiency of common bridge vibration detection methods and acquired advantages such as high precision,easy operation,simple structure and low expense.Experiments of the bridge of Beijing Metro Line 13 which passed across north fourth ring road proved that the radar can measure the bridge's vibration rightly.The paper proposed a bridge vibration measure method based on radar echo data.Meanwhile,the radar acquired the micro-deformation message effectively and increased the resolution and efficiency for the bridge vibration monitoring.It was of great potential and could been applied to regions such as bridges monitoring,alarming and maintenance.

    Global Height Datum Unification Using Geodetic Boundary Value Problems Algorithm
    ZHAO Dejun, XU Xinqiang, OUYANG Mingda
    2018, 0(4):  83-87.  doi:10.13474/j.cnki.11-2246.2018.0115
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    In order to unify height datums in different countries,an algorithm based on geodetic boundary value problems (GBVP) is presented,which utilizes satellite gravity field models,terrestrial gravimetric data,GNSS geodetic heights,orthometric heights or normal heights.First of all,the algorithm to determinate height datum geopotential difference using conventional terrestrial "biased" gravity anomalies is deduced.Secondly,the indirect biased term is neglected by using modified Stokes kernel function.A geoid that is not related to any local vertical datums is obtained by combining satellite-only gravity field models and terrestrial "biased" gravity anomalies.That independent geoid is then adapted to determinate height datum geopotential difference.At last,the geopotential difference between US vertical datum (NAVD88) and world geoidal geopotential W0 is determined through GBVP by combining GNSS/leveling benchmark data and gravity geoid,which is about -4.82±0.05 m2s-2.

    Performance Evaluation of BDS/GPS Dual System Combination GBAS
    YU Geng, ZHANG Binhao, ZHAO Long
    2018, 0(4):  88-91.  doi:10.13474/j.cnki.11-2246.2018.0116
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    With the development of BDS,the global networking process is carried out,BDS/GPS integrated navigation has become an important method to improve the performance of navigation,and the ground augmentation system (GBAS),as a new generation of navigation mode for precision navigation,is the focus of current research.In this paper,through the derivation of BDS/GPS double system combined GBAS model,respectively to BDS,GPS as independent GBAS navigation source and BDS/GPS navigation accuracy as factor GBAS navigation source system (DOP),vertical protection level (VPL) performance are analyzed,and the superiority of GBAS performance in integrated navigation system is verified.The result shows that GBAS based on GPS and BDS are close to each other and have their respective advantages,BDS/GPS combined GBAS outperforms the single system.

    Improved Kalman Filtering Algorithm for GNSS RTK Multi-system
    FAN Hongping, ZHOU Zhifeng, WANG Yongquan
    2018, 0(4):  92-95.  doi:10.13474/j.cnki.11-2246.2018.0117
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    For the multi-system GNSS RTK feature,the integer ambiguity is introduced in this paper.However,due to the increase of visible satellite,the dimension of the state vector will increases sharply,which leads to a large number of multi-dimensional matrix multiplication.And the covariance calculation and storage capacity account for 70% of the total Kalman filtering process time.In order to improve the efficiency of the algorithm,an improved Kalman method for sparse state transition matrices is proposed.This paper mainly discusses the solution of covariance matrix and uses matrix block units with symmetry to reduce the multiplication times to less than 10% of the general algorithm.The experimental result is that the improved method of CPU processor takes less than 10% of the general algorithm.This improved method achieves high efficiency,which also has certain reference value for other filtering algorithms.

    The REHSM Model Improved by Least Square Collocation Method and Its Application
    WANG Dongdong, ZHANG Jun, DENG Xiaodong, LIU Jigeng, ZHAO Xukun
    2018, 0(4):  96-99,130.  doi:10.13474/j.cnki.11-2246.2018.0118
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    It is known that the traditional rigid plate rotation motion model(RRM) can not take into account the deformation of the intraplate,which is up to now seems to have been solved by the overall rotation with homogeneous strain model(REHSM).However,there is still limitation in describing the deformation of the intraplate because of that the "homogeneous" assumption is difficult to be satisfied in many complex geological tectonic regions.Therefore,a new model of REHSM improved by least square collocation is presented to enable the model of REHSM to have a wide applicability.The results of the analysis of the velocity field data of the recent GPS observations from "China Tectonic Environment Monitoring Network" in the Bohai sea area show that it is feasible and more reasonable to use the new model to analyze the crustal deformation.

    Using GRACE Data and Geophysical Models to Analyse Earth's Dynamic Oblateness Changes
    CHEN Pinxin
    2018, 0(4):  100-103.  doi:10.13474/j.cnki.11-2246.2018.0119
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    As a rotating ellipsoid,the dynamic oblateness (J2) changes of the earth is significantly influenced by the interaction of different layers in the earth system and the redistribution of earth's fluid mass.At present,the dynamic oblateness is usually obtained from the satellite laser ranging (SLR) data.A new method is proposed to estimate changes in the earth's dynamic oblateness,which uses monthly gravity recovery and climate experiment(GRACE) gravity solutions,an ocean bottom pressure model and a glacial isostatic adjustment (GIA) model.The result shows that the time series is similar with the solution based on SLR data.The experiment shows that seasonal variations of the obtained time series are similar with different GRACE data products,which is approximate with the solution based on SLR.

    Improvement of MSAC for Estimating F and H Matrix to Filter Matching Points
    LI Cheng, WANG Renli, WANG Chenggang, MING Pingshou
    2018, 0(4):  104-107,140.  doi:10.13474/j.cnki.11-2246.2018.0120
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    Aiming at the problem of mismatching in stereo image matching,mismatches are usually eliminated by some kinds of constraint.In the multi-view geometry,fundamental matrix and homography matrix are usually used to constrain the location of the corresponding points.In this paper,an improved robust MSAC algorithm is used to estimate the fundamental matrix and homography matrix to filter the mismatches of images of different types of objects.The experimental results show that:①The improved MSAC algorithm is superior to the original algorithm;②The homography matrix is suitable for the flat area images,and its binding force is higher than fundamental matrix.The fundamental matrix is suitable for any stereo images.

    Change Detection Using High Spatial Resolution Remote Sensing Images for Illegal Land Use Extraction
    CHEN Peng, LÜ Pengyuan, SONG Mi, ZENG Fanyang, WU Siqi, ZHONG Yanfei
    2018, 0(4):  108-111.  doi:10.13474/j.cnki.11-2246.2018.0121
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    With the development of high spatial resolution remote sensing images,it is possible to automatically detect illegal land use based on high resolution remote sensing images.In this paper,a multiple feature based automatic change detection framework using high spatial resolution remote sensing image is proposed to find the illegal land use.The study area is Guangzhou and the method is tested on a high spatial resolution data set.The experimental result shows that the potential of the proposed method can increase change detection accuracy while reduce the time consuming manual work.

    Semi-automatic Extraction of Rectangular House Contours from Aerial Images
    LI Dajun, DU Shenbin, GUO Bingxuan, XUE Wanchang, YOU Qi
    2018, 0(4):  112-115,120.  doi:10.13474/j.cnki.11-2246.2018.0122
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    In order to extract the contours of the house for the purpose accurately,this paper proposes a semi-automatic extraction algorithm for rectangular house contours in aerial images.The first step of this algorithm is using mouse manually to draw straight lines in the approximate position of house contours in turns,and next step is using image segmentation to achieve the corresponding window images.Then using LSD algorithm to extract straight lines from window images.After that,considering it as the initial value,the least squares algorithm is applied to carry on curve fitting and right angle processing on the original image in case of ensuring its overall displacement and numerical deviation are the minimum.The last step is connecting angular points,and the extraction of the house contours information is done.The experimental results show that this method can reduce labor intensity efficiently and the position accuracy is higher than artificial work.

    Study on Recovering Pose of Low Altitude UAV Images Using Essential Matrix
    ZHANG Jingjing, WU Liangcai, AI Haibin, XU Biao, ZHAO Dongliang
    2018, 0(4):  116-120.  doi:10.13474/j.cnki.11-2246.2018.0123
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    With the widespread use of UAV,the emplacement of the camera and direction of the camera can be arbitrary.This leads to the diversification of the image baseline direction.It is difficult to process such images with traditional photogrammetric method.This paper proposes a strategy based on essential matrix for recovering pose of aerial image.It is proved that the orientation measurement proposed in this paper can not only determine the baseline direction quickly and solve exterior orientation parameters of images,but also guarantee the re-projection error within one pixel in terms of accuracy using our proposed strategy.

    Extraction of the Building's Top Patch Based on the Rules of LMedS Algorithm
    CHEN Xiangyang, XIANG Yunfei
    2018, 0(4):  121-124.  doi:10.13474/j.cnki.11-2246.2018.0124
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    In view of the common plane fitting method can appear the problem of the unfitting under the condition of the existence of "noise points",the RANSAC algorithm can extract the top patch of building from airborne LiDAR data with better robustness.When the RANSAC algorithm is fitted with parameters,there will be some defects,which can achieve better fitting effect by improving the RANSAC algorithm (LMedS algorithm).The point cloud data is filtered using the pass-through filter,and then the point cloud data is sampled by the VoxelGrid filter.For the sampled point cloud data,the top surface of the building is extracted using LMedS algorithm.The experiment results show that the LMedS algorithm can successfully extract the top patch of building.At the same time,it has a good robustness.

    Design and Implementation of Online Interactive Visualization Tool Based on Vector Tiles
    SONG Lei, HUO Liang, FANG Min, BAO Peng, WANG Rui, WANG Jindi
    2018, 0(4):  125-130.  doi:10.13474/j.cnki.11-2246.2018.0125
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    The online mapping not only pays attention to the mapping speed,but also takes into account the characteristics of visualization. To address this problem, this paper proposes an user oriented online interactive visualization method for network maps.The method is based on vector tile technology,gradually transmitted GeoJSON format data to the client side by WFS,and cached in the browser.Users can edit map symbols,determine the parameters of map symbols and layers at the browser and render vector data into graphics by this tool.The interactive online visualization tool bases on this method,which makes full use of the client CPU and GPU computing resources in WebGIS system.It resolves the user's setted style information through scripting language,and renders the vector data in memory into graphics and display dynamically by WebGL technology,which reduces the dependence of data rendering on the server side,enriches the way of map expression.

    Spatial Information Intelligent Service Framework for Geological Environment Evolution of Urban Agglomeration
    ZHANG Dandan, LI Man, FU Zhengbo, LI Haochuan
    2018, 0(4):  131-135.  doi:10.13474/j.cnki.11-2246.2018.0126
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    Based on the big data characteristics of geological environment evolution of urban agglomeration,as well as spatial information service demand on the zone planning,construction and management of urban agglomeration,a spatio-temporal big data driven spatial information intelligent service framework of geological environment evolution was proposed in this paper,which was also multi-objective application aimed.The framework includes a large data collection and processing layer,data organization and management layer,calculation and analysis of large data mining layer,service layer and application layer.The framework has good practicability and expansibility which can form a new mode of spatial information application service of comprehensive geological environment evolution.

    Key Technology Research on the Whole Process Intelligent Service Platform of Urban and Rural Planning Inspection and Mapping
    YUN Fachang, LI Wangmin, LI Bin, DING Jianxun, HUANG Xiao
    2018, 0(4):  136-140.  doi:10.13474/j.cnki.11-2246.2018.0127
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    Domestic inspection and mapping of urban and rural planning mainly focus on the positioning and acceptance of key nodes in the construction process at present.The design and development of related assistant system and the division of mapping phase are also the primary basis of related research,which gives less concern on the development of planning inspection and mapping informatization service system and the fusion of informatization and collaborative sevice.The critical technology of intelligent service for the whole process of urban and rural planning inspection and mapping is discussed in this paper,and a scheme on the construction of the the intelligent service platform is also proposed based on the concrete practice.

    The Automatic Learning Method of High Speed Railway CPⅢ Point Based on the Intelligent Total Station
    CHEN Zeyuan
    2018, 0(4):  141-145.  doi:10.13474/j.cnki.11-2246.2018.0128
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    High speed railway CPⅢ plane control network requires high precision and the measurement task is complex,usually using high precision measuring robot forautomatic measurement.This paper studies deeply the network scheme and the measuring method of the CPⅢ plane control network,and proposes an automatic learning method of adjacent station public CPⅢ control points,and uses the C# language to write the program for CPⅢ data acquisition software.Through practical engineering verification,this method can ensure that the robot can accurately locate the target point and improve the efficiency of the field process.

    Accuracy Analysis of Data Processing for Long Baseline Based on TBC 4.0 Software
    ZHU Zhaorong, ZHANG Xiyue, ZENG Yanyan, JIANG Guohui
    2018, 0(4):  146-149.  doi:10.13474/j.cnki.11-2246.2018.0129
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    In response to the demand for high-precision data processing in engineering surveying,the new version TBC 4.0 software developed by the Trimble company is not only compatible with multi-navigation positioning system,but also significantly improves the accuracy of long baseline solution.In this paper,based on the observation data of IGS,the baseline solution accuracy of TBC 4.0 software is compared with that of Bernese software and GAMIT software,and compared with the solving ability of TBC software for old version.The results show that in the presence of a long baseline of 1000 km,the resolution accuracy of TBC 4.0 software is comparable to that of Bernese and GAMIT software,with a three-dimensional position accuracy of mm level.What's more,it is not limited by the type of ephemeris.In addition,the ability of baseline solution for TBC 4.0 software has been greatly improved compared with the old version of TBC.

    Application of Trimble TX8 3D Laser Scanner in Capacity Measurement of Vertical Metal Tanks
    WANG Yanxia, GU Tianping, ZHANG Zhiqing, LU Xingjie
    2018, 0(4):  150-151,158.  doi:10.13474/j.cnki.11-2246.2018.0130
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    The 3D laser scanner provides the basis for realizing the high efficiency and high accuracy of the vertical metal tank capacity measurement.By analyzing the working principle of the Trimble TX8 3D laser scanner,the measured data of the 150 m3 vertical metal tank capacity measurement is modeled and analyzed.The experimental data shows that the Trimble TX8 is more consistent,efficient,and intuitive in terms of vertical tank volume measurement and basic volume transfer method data.In particular,its comprehensive visualization of sampled data can be extended to tank deformation,stress analysis modeling and other aspects,and offers the possibility to extend to other abnormal tank related volume values and other related analytical measurements.
    Application of UAV Airborne LiDAR Technology to Electric Power Industry
    PENG Jinsong, XU Jun, LI Juan
    2018, 0(4):  152-154.  doi:10.13474/j.cnki.11-2246.2018.0131
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    With the development of laser radar technology,LiDAR can be used for power inspections.The traditional patrol method is not high in spatial positioning accuracy,and it is difficult to accurately determine the distance from the ground to the line of the corridor and can not be quickly classified. The rapid development of drone technology also provides a convenient and efficient carrier platform for laser measurement.UAV laser measurement system can better solve these problems and comprehensively obtain data information such as transmission line body,corridor,and equipment operation status.Establish a management system with the functions of transmission,storage,and display of information to realize real-time,comprehensive,and efficient 3D visualization management of transmission lines.
    Application of Multi-rotor UAV in Surveying and Mapping of Engineering Earthwork
    GAO Limin, FENG Yaolou
    2018, 0(4):  155-158.  doi:10.13474/j.cnki.11-2246.2018.0132
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    Multi-rotor unmanned aerial vehicle (UAV),as a kind of low cost,high precision,simple operation of the remote sensing image acquisition platform,has achieved good results in the traditional measurement of surveying and mapping,digital city construction,disaster emergency response applications etc.Taking the application of Topcon Falcon 8 eight-rotor UAV platform as an example,through the data analysis of multi-rotor UAV platform for low-altitude photogrammetry,we use Virtual Surveyor software to calculate the amount of earthwork in two periods and provide accurate data and powerful technical support for engineering management.