Table of Content

25 December 2019, Volume 0 Issue 12

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Research on real-time positioning of underwater robot based on ORB-SLAM2 algorithm

ZHANG Yang, LI Haisen, MA Li, WANG Jian, GUO Qijia, QI Jing, YAN Ming

2019, 0(12):  1-7.  doi:10.13474/j.cnki.11-2246.2019.0375

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With the rapid development of visual SLAM in recent years, it provides more choices for navigation and positioning of robots, drones, and automobiles. Aiming at the problems of complex systems and difficult operation of current underwater robot positioning technology, this paper proposes an underwater positioning scheme based on ORB-SLAM2 algorithm. Using the monocular camera as the sensor, the monocular vision SLAM underwater robot positioning model is constructed, and the conversion from pixel coordinate system to world coordinate system is completed. The key technologies involved in ORB-SLAM2 algorithm positioning are introduced. The underwater positioning performance of the ORB-SLAM2 algorithm is comprehensively evaluated by the underwater ideal environment experiment. The marine environment experiment proves that the ORB-SLAM2 algorithm can effectively locate the underwater robot in real time.

Research on indoor positioning of LiDAR SLAM mobile robot

YAN Xiaoyi, GUO Hang

2019, 0(12):  8-11.  doi:10.13474/j.cnki.11-2246.2019.0376

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Aiming at the low accuracy and cumulative error of indoor mobile navigation, a fusion navigation system based on light detection and ranging (LiDAR) and inertial measurement unit (IMU) is proposed. First, the method extracts environmental features and constructs maps from LiDAR scan measurements. Then, the pose information collected by the IMU compensates for the position and attitude output errors caused by LiDAR scans by Kalman filtering to improve the positioning of the robot movement precision. The experimental results show that the method can improve the accuracy and robustness of indoor mobile robot positioning and map construction.

Fusion location method of stereo vision inertial navigation system in indoor environment

AO Longhui, GUO Hang

2019, 0(12):  12-17.  doi:10.13474/j.cnki.11-2246.2019.0377

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Aiming at the navigation and positioning problem of indoor service robots in the home environment, this paper studies the stereo-integrated inertial fusion navigation method based on tightly coupled nonlinear optimization. The method adopts key technologies such as pre-integration, edge-based and sliding window optimization, and proposes a robust initialization method of visual inertial navigation system. Used in indoor home service robots, the corresponding visual inertial fusion navigation system is designed and implemented. In the simulated home environment, the initialization method of the system can provide robust and accurate initial values. Finally, the accuracy and stability of the positioning system are verified by experiments. The positioning error can be controlled within 0.1 m.

PDR algorithm improves indoor positioning accuracy of geomagnetism

HUANG He, ZHANG Xinyu, QIU Kaiyue

2019, 0(12):  18-21.  doi:10.13474/j.cnki.11-2246.2019.0378

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The use of geomagnetic field disturbances caused by metal structures in the building can locate indoor pedestrian targets, and the positioning based on the geomagnetic field does not require any additional facilities, so positioning can be achieved at low cost. However, only a single geomagnetic technique could not meet the accuracy requirements of indoor positioning. In order to solve the ambiguity problem of single point positioning in magnetic field data, we propose an indoor positioning method that uses particle filter algorithm to fuse PDR with geomagnetism and develops. The geomagnetic indoor navigation system uses the smart phone as the hardware platform to construct the magnetometer sensor model, establishes the mean square error criterion of the matching trajectory and realizes the iterative calculation of the PDR cumulative error real-time correction. In the experimental area of 68 m×1.8 m, the average positioning error is 1.13 m and the maximum positioning error is 2.17 m. The positioning accuracy of the fusion algorithm proposed in this paper is 42% higher than that of the single PDR algorithm. Compared with the positioning of a single geomagnetic fingerprint matching algorithm, the positioning accuracy is improved by 57%. Experiments show that the proposed fusion algorithm has a significant effect on improving indoor positioning accuracy.

Extraction of lane line from high resolution remote sensing image

ZHANG Shiqiang, WANG Guishan

2019, 0(12):  22-25.  doi:10.13474/j.cnki.11-2246.2019.0379

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Lane line is an important part of the high definition(HD) map. This paper discusses the method of lane line extraction using high resolution remote sensing image. According to the histogram principle, the appropriate threshold is selected for binarization segmentation, the buffer formed by the road center line is used to remove the elements outside the range of the road, and the morphological operator is used to remove the noise. Shape and direction feature used to distinction lane line. This method can reduce the cost of data collection and improve the efficiency of data collection.

An improved method for high precision map registration

WANG Miao, XUE Yufei, GE Junxia, GUO Zhaozhong

2019, 0(12):  26-29.  doi:10.13474/j.cnki.11-2246.2019.0380

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Aiming to solve the problem that the high-precision map data collected at different times or different devices cannot be matched well, this paper proposes an algorithm of realizing high-precision map registration using the regularized local-weighted thin-plate spline algorithm. The K-D tree is used to search the local neighborhood control points to generate a regularized local thin plate spline transformation field. The elements to be registered are locally weighted to generate the post-registration elements. The experimental results show that this algorithm is superior to the traditional linear least squares algorithm and improves the registration success rate.

Study on the UHV transmission tower’s interferometry and icing character in TerraSAR spotlight images

CHEN Lulu, LI Tao, LIU Yan, LIU Jingnan

2019, 0(12):  30-34.  doi:10.13474/j.cnki.11-2246.2019.0381

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This paper studies the Ultra High Voltage (UHV) transmission tower radar scattering mechanism and interferometry in TerraSAR Spotlight images. LiDAR scanning and 3D modeling tower, we analyze the scattering geometric relationship of tower's different parts based on the SAR geometric imaging relationship. Comparing and analyzing the height difference between the cross-arms of the tower based on the scattering intensity and phase change, the results show that the phase estimation is greatly interfered by the noise. In this paper, the theoretical analysis and data statistics of the radar image of the ice tower are carried out. The results show that the 10 cm ice thickness damages the dihedral scattering condition of the tower component, which causes the radar scattering signal intensity to attenuate significantly by about 8 dB. It is verified that the radar scattering intensity changes of transmission tower can be used to evaluate quantitatively the ice coating status.

Registration of side-scan sonar image based on contour

LI Zhiyuan, DOU Hulin, HU Jun, WU Zijing, WU Yongting

2019, 0(12):  35-39,49.  doi:10.13474/j.cnki.11-2246.2019.0382

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Aiming at the problem of inconsistency of common-view targets caused by local distortion in side-scan sonar images, this paper presents a contour-based registration framework for side-scan sonar images. Firstly, the target contour is extracted and the environmental context description of each contour point is calculated, with the χ² test statistics of the environmental context as the cost function. Then, the corresponding relationship of contour points is obtained by minimizing the cost of all matching points. Finally, the regularized thin-plate spline function is used to solve the image transformation relationship, and the contour is established. Correspondence of internal pixels. Experiments show that this method can effectively ensure the consistency of common-view targets, and has a certain reference value.

ICP image matching technology considering distorted image edge

GAO Li, JIN Fei, JIANG Zhenzhi, WANG Fan, RUI Jie

2019, 0(12):  40-44.  doi:10.13474/j.cnki.11-2246.2019.0383

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Matching technology is an important basic technology in remote sensing image processing. The difference between radiation and geometric information of images seriously interferes with similar feature matching between images. This paper proposes an algorithm of ICPDI for large difference images. Firstly, it improves the parameter setting method of the Canny operator for selecting the long edge of the image as a prominent feature of image matching. Then, it takes the distance between line features as the similarity evaluation standard for achieving the purpose of suppressing local differences by using global similar features. Finally, it adds a deformation function to the edge of the image for extending the scope of ICPDI matching technology. The accuracy and adaptability of the proposed method are verified by matching experiments between different types of remote sensing images.

Automatic and accurate cloud detection for Fengyun meteorological satellite

LIU Jun, ZHENG Qunfeng, XING Xiuwei, CHEN Xunlai, CHEN Qian, QIAN Jing

2019, 0(12):  45-49.  doi:10.13474/j.cnki.11-2246.2019.0384

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The matting technique can accurately detect the difference between the foreground and the background, but most of the existing matting algorithms need to give the foreground and background markings in advance, which has obvious limitations in the mass image processing. In this paper, the matting technology is introduced into the cloud detection of Fengyun meteorological satellite images, and an automatic fine cloud detection algorithm based on connected regions is proposed. Firstly, the gray visible image is binarized by ensemble threshold methods, and the preliminary bipartite map is obtained by the voting method. On this basis, the connected regions are calculated, and the center of gravity of the connected regions are taken as the seed point, and then triple map based on the connected regions is automatically generated. Finally, the closed-form matting algorithm is used to solve the alpha value to obtain fine cloud detection results. The proposed method is compared with the learning and robust matting-based cloud detection algorithms. The experiments show that the proposed method can automatically detect multiple types of clouds better and has higher accuracy.

Image similarity learning via two-branch network architecture

LU Jian, MA Chengxian, ZHOU Yanran, LI Zhe

2019, 0(12):  50-55.  doi:10.13474/j.cnki.11-2246.2019.0385

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Image similarity learning is to predict whether two images match by learning image content information through the network. Until now, the improved variant network based on convolutional neural network has effectively improved the learning efficiency. However, because the extracted features are relatively single and cannot accurately describe the image features, the similarity learning efficiency is low. To this end, a two-branch network based on a convolutional neural network structure is proposed. The network is a left and right branch network, the structure is the same but the weights are not shared, and the network input is a two-branch input. Firstly, the single channel image features are extracted by the left and right branch networks respectively. Then the features fused through the feature fusion layer. Finally, the fusion feature is directly input into the fully connected layer for similarity learning. It not only improves the feature diversity of the extracted images, but also speeds up the training of the model. Comparative experiments were carried out on the chip card slot image dataset taken by the laboratory industrial camera. The experimental results show that compared with other models, the proposed model has strong network learning ability and model generalization ability, and the accuracy rate is 97.96%.

Research on united extraction and cross matching of UAV image features

JI Wenlai, ZHAO Xiangyu, LI Mingfeng

2019, 0(12):  56-59,64.  doi:10.13474/j.cnki.11-2246.2019.0386

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Aiming at the problem of UAV images with large number and changes of rotation and scaling, a method of image registration based on united extraction of features and cross matching is proposed. The characteristics of SURF algorithm and BRISK algorithm are analyzed. The algorithms and steps of united extraction of image features with SURF feature point detection and BRISK feature point description and PROSAC cross matching are studied. The validity of this method is verified by experimental analysis.

A fast spectral clustering algorithm for hyperspectral remote sensing images

ZHANG Yaping, ZHANG Yu, YANG Nan, LUO Xiao, LUO Qian

2019, 0(12):  60-64.  doi:10.13474/j.cnki.11-2246.2019.0387

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In order to obtain a better classification method of remote sensing images and solve the problem of slow classification operation of hyperspectral remote sensing images, this paper integrates Lanczos algorithm and spectral clustering algorithm, discusses the feasibility of spectral clustering algorithm of hyperspectral remote sensing images applied to remote sensing image classification, and proposes a hyperspectral remote sensing image-oriented fast spectral clustering algorithm. By comparing the classification results of K-means algorithm and spectral clustering algorithm for hyperspectral remote sensing image of San Diego Airport, USA, it is found that spectral clustering algorithm for hyperspectral remote sensing image is easy to recognize linear features, and the classification speed can be greatly improved.

Building outline extraction based on airborne LiDAR data

ZHU Yimin, TIAN Linya, BI Jixin, LIN Song

2019, 0(12):  65-70.  doi:10.13474/j.cnki.11-2246.2019.0388

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As an important element of 3D reconstruction of buildings, building contours are crucial in building smart cities and digital cities. Aiming at some problems in the extraction of point cloud filtering, building roof surface extraction, building contour extraction and extraction accuracy evaluation from the airborne LiDAR point cloud, this paper proposes a comprehensive region growth improvement algorithm, three-dimensional Hough transform algorithm and α-shape algorithm for building contour extraction method. Based on the denoising of airborne LiDAR point cloud data, the method uses an improved region growing algorithm to filter the ground points and removes the lower height features through the height threshold based on the normalized elevation features of the ground point to the ground. Then, based on the three-dimensional Hough transform algorithm, the building plane is extracted from the remaining buildings and the tall tree point cloud, and finally the contour information of the building is extracted using the α-shape algorithm. The point cloud data of a certain urban area scanned by the RIEGLVQ-1560i airborne LiDAR measurement system is calculated, and the accuracy of the extracted building outline is evaluated by the evaluation indexes such as matching degree, shape similarity and positional accuracy. The results show that the integrated region growth improvement algorithm, three-dimensional Hough transform algorithm and α-shape algorithm for building contour extraction method can accurately extract the contour information of buildings, and have the characteristics of stability and universal applicability for wide-area building contour extraction.

Water body extraction from OLI remote sensing images based on spatial-spectral angle matching and multi-index method

ZHANG Qihua, WANG Shengli, SUN Lei, JIANG Yi

2019, 0(12):  71-76.  doi:10.13474/j.cnki.11-2246.2019.0389

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Aiming at the disadvantage of low precision of water body remote sensing extraction under complex environment, a water body information extraction method based on space-spectral angle matching and multi-index method is proposed. Compared with single-band threshold method, normalized difference water index method (NDWI), spectral angle matching method (SAM), automatic water extraction index method (AWEI) and one-class support vector machine (OC-SVM), the water extraction results are analyzed and the accuracy is evaluated. Experiments in two research areas on Landsat 8 OLI images show that the new method takes into account the complementary advantages of multi-features. The spatial information introduced can effectively suppress noise and the pixel-based extraction strategy can maintain the edge information of the water body better, and avoid the situation of smoothing the details. Compared with traditional methods, this method is least disturbed by vegetation, buildings and shadows, and has better recognition ability for small water bodies.

Land use analysis of plateau lake watershed based on GF and multi-source data

LIU Bin, BAI Shaoyun, YU Peiheng, CHEN Min, PAN Jiawei, CHEN Yiyun

2019, 0(12):  77-82.  doi:10.13474/j.cnki.11-2246.2019.0390

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GF-1 satellite is an autonomous satellite launched to improve the self-sufficiency of high-resolution data in China. It has an important application in land use monitoring. Comparison between GF-1 satellite images and multi-source images can excavate the differences of various data sources in land use dynamic monitoring. In this paper, the Qilu lake watershed in Yunnan province is taken as the research area. The latest Sentinel-2, GF-1 and Landsat 8 remote sensing images are selected for land use classification. Based on the data of the second national land use survey, the current situation and evolution of land use are analyzed by combining field investigation and land use transfer matrix. The results show that:① The water area, construction land, cultivated land and forest land in Qilu lake watershed show the characteristics of circle distribution from the center to the outside. Compared with the results of the second national land survey, the natural landscape area of water area, arable land and forest land is reduced, while the area of construction land and other land is greatly increased under the influence of human activities, and the changes are mainly concentrated around Qilu lake, with Nagu town and Hexi town as the typical examples. ② Both Sentinel-2 satellite image and GF-1 satellite image have high spatial resolution. The results of land use change assessment derived from Sentinel-2 and GF-1 are similar and both are better than that derived from Landsat 8 satellite image. GF-1 satellite image has high application potential.

Remote sensing retrieval of vegetation equivalent water thickness based on mixed pixel decomposition theory

XIAO Xianghong, LIU Haiyang, GUO Yunkai

2019, 0(12):  83-86,95.  doi:10.13474/j.cnki.11-2246.2019.0391

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In order to reduce the influence of mixed pixels on the inversion of vegetation parameters, an inversion of the equivalent water thickness of road vegetation is proposed based on the mixed pixel decomposition theory.In this paper, we use the hyperspectral narrow-band data obtained by PRO4SAIL model to simulate the broad-band vegetation canopy spectral data of Landsat 8 remote sensing image, and screen the sensitive vegetation index of equivalent water thickness.In addition, linear mixed pixel decomposition of Landsat 8 remote sensing images covering the study area is performed to obtain more accurate spectral reflectance of vegetation canopy.At the same time, the support vector machine is used to construct the equivalent water thickness estimation model to realize the remote sensing inversion of the equal water thickness of the vegetation in the road area.The results show that the equal water thickness of the vegetation in the vegetation inversion obtained by the decomposition of the vegetation canopy obtained by the mixed pixel is more in line with the actual situation, and provides effective data for the inversion of vegetation parameters by remote sensing images.

Real-time monitoring of instantaneous crustal deformation by integrating GPS and strong seismometer data

CHEN Xiangyang, YU Jinchi, GE Jian, HOU Yongtao

2019, 0(12):  87-90,115.  doi:10.13474/j.cnki.11-2246.2019.0392

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In view of the merits and drawbacks of strong motion (SM) and GPS, taking the Mw 6.0 Italy earthquake as a subject, the feasibility of Kalman filter to combine GPS and SM data, and then to conduct the real-time monitoring of instantaneous crustal deformation caused by moderate earthquake using fusion is discussed. The displacement waveform obtained by Kalman filtering uses GPS data as the overall trend, and the details are described by the SM displacement data. The combined displacement waveform has higher precision and can accurately and meticulously describe the coseismic ground dynamic deformation caused by earthquakes. At the same time, the Kalman filter displacement waveform can accurately detect the coseismic permanent offsets caused by moderate earthquake. The power spectrum density (PSD) of combined displacement waveform is similar to that of GPS displacement waveform in the low-frequency regions, while it is similar to the PSD of SM displacement waveform in the high-frequency regions, indicating that Kalman filtering can combine the advantages of GPS and SM. The spectral index of the displacement waveform obtained by Kalman filtering is different from that of GPS and SM displacement waveforms, indicating that the fused displacement waveform can better describe the variation of the noise characteristics of displacement waveform data caused by the earthquake. Cross-wavelet analysis shows that the displacement waveform obtained by Kalman filter has strong positive correlation with GPS and SM data, and the cross wavelet semblance is above 0.8. The above results show that the combined displacement waveform can combine the advantages of GPS and SM to make up for their defects. The combination of GPS and SM can effectively detect the transient crustal deformation induced by the earthquake with moderate magnitude.

Research on measuring wind speed and direction of rotor UAV

HE Cheng, Lü Zhenyi, LI Jin, WANG Yue, SHU Lifu

2019, 0(12):  91-95.  doi:10.13474/j.cnki.11-2246.2019.0393

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At present, most civil UAVs do not accurately measure wind speed, wind direction and early warning wind field. However, forest fire fighting and other scenarios require them to provide accurate wind speed. In this paper, a wind speed and wind direction measuring technology based on the coordinate data of the rotor UAV is proposed. The relative coordinate information of the propeller point is accurately obtained by the RTK (real time kinematic) coordinate information and the azimuth and inclination data. The rotor UAV with different carriers is flying at different speeds of 1 m/s to 16 m/s for more than 30 seconds. According to the change value of the propeller coordinate information, combined with the wind tunnel test data and the wind field dynamics principle, the relationship between the wind speed and the azimuth is studied. The accuracy of the method is tested by wind tunnel experiments. The wind direction can be judged based on the propeller coordinate change information calculated by the RTK. The results show that the wind speed is positively correlated with the azimuth. When the carriers is increased, the azimuth corresponding to the wind speed disturbance would be relatively reduced. The probability of the UAV flight being affected by the gust disturbance, the high altitude area is larger than the low altitude area, and the wind speed estimation model of the flying angle of the six-rotor UAV is established, y=-1.043 5+1.150 1x, the median error value of wind speed measured by this model is 0.966, and the absolute value is less than 1, which meets the requirement of wind speed measurement accuracy of UAV on the scene of emergency command. The method had high accuracy of wind speed measurement, and could provide a feasible method for real-time wind speed and direction measurement of the rotor UAV which had certain practical value.

Spark parallel optimization large-scale spectral clustering

Lü Honglin, YIN Qingshan

2019, 0(12):  96-100.  doi:10.13474/j.cnki.11-2246.2019.0394

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To solve the problems of computational time-consuming and resource occupation, which is hard to be prevented in existing spectral clustering on large-scale datasets, based on the Spark technology, an improved parallel optimization algorithm for spectral clustering is proposed. In which, repetitive calculation of data in similar matrix calculations is avoided by parallel one-way iteration, the resource occupancy is optimized by the parallel position transformation, the scalar multiplication replacement and the distance scaling, and the calculation amount is further optimized by the use of the approximate eigenvectors. The experimental results verify the effectiveness of the approximate eigenvectors and the good clustering performance and scalability under large-scale data sets.

Visualized analysis framework on big geo-information data oriented spatio-temporal events

LI Jinlei, CI Yuyao, ZHENG Kun, GUO Shaolong, YAN Jihong, CHEN Yuping, WU Yanmin, LI Shiyi

2019, 0(12):  101-104.  doi:10.13474/j.cnki.11-2246.2019.0395

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Rich spatio-temporal relations are hidden in types of big geo-data, which represent the evolution of individual or collective spatio-temporal events and play a decisive role in intelligent applications such as natural resources, environments, transportation and other fields. However, there are many difficulties in digging the spatio-temporal relationship, due to the large number of attributes embedded in multi-scale and multi-semantic big geo-data. It is a technical challenge to effectively construct multi-scale and multi semantic spatio-temporal and as well as to visualize the relations. In this paper, we design an analysis framework to visualize the spatio-temporal relations among spatio-temporal events. we design a multi-view collaboration to visualize the spatio-temporal relations among events by describing a general definition for spatio-temporal relations in spatio-temporal events. A visual interface is presented for users to interactively select or filter spatial and temporal extents to guide the knowledge discovery process. Followed by experimental application on spatio-temporal trajectory data shows that this method can explore the spatio-temporal relationship between spatio-temporal events and context, and realize the interactive visual analysis of spatio-temporal events.

A multi-antenna directional attitude measurement method based on BeiDou navigation system

JIAN Haibo, WANG Jie

2019, 0(12):  105-107.  doi:10.13474/j.cnki.11-2246.2019.0396

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With the continuous improvement of BeiDou navigation system and the emerging development of BeiDou industry, many satellite navigation technologies based on BeiDou system are applied to all aspects of the military and civilian. In this paper, a damped LAMBDA algorithm is proposed. The BeiDou data is used to realize the single-frequency single-epoch solution of the ultra-short baseline for the multi-antenna attitude calculation of the platform. The simulation data and field tests verify the proposed multi-antenna attitude calculation algorithm.

Urban fine management based on multi-source spatial data fusion

ZUO Hailong, LUO Hongxia

2019, 0(12):  108-111,151.  doi:10.13474/j.cnki.11-2246.2019.0397

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The increasing management of urban management and the wide variety of management objects have become important issues affecting the sustainable development of cities. Under the background of nationwide smart city construction, citing new technologies to improve the level of urban refined management can enable the city's management units to exchange information in a coordinated, accurate and timely manner, forming a supporting plan for smart city management, and allowing limited management resources to play out. The maximum use efficiency, to achieve the optimal goal of urban management, and promote sustainable economic development. This paper proposes a technical solution for spatial data fusion such as geographic information system, GPS, remote sensing and RFID. It emphasizes the improvement of the comprehensive level of urban refined management through workflow and process management on the basis of spatial information and mobile information management. Public participation in monitoring urban management and smart city construction provides a reference.

Research on multi-source geospatial vector data fusion

YANG Can, WANG Qisong

2019, 0(12):  112-115.  doi:10.13474/j.cnki.11-2246.2019.0398

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With the arrival of the era of geographic information big data, geographic information and multiple industries are increasingly deeply integrated, resulting in a large number of heterogeneous multi-source data.Multi-source and rich spatial data provide basic support for economic and social development, while its heterogeneity also brings problems and challenges to data sharing and application.In view of the current situation and characteristics of multi-source, heterogeneous and inconsistent geospatial data, this paper puts forward the process and method of multi-source geospatial data fusion, which integrates database model fusion and database instance fusion, and analyzes the case data such as fundamental geographic information and national census geography, which provides a solution for multi-source spatial data sharing and application.

Study on suitability expansion path of construction land in Nanchang city

FENG Xiangrui, CHEN Zhuan, WEI Xiaojian, SHI Chenjing

2019, 0(12):  116-121.  doi:10.13474/j.cnki.11-2246.2019.0399

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In the process of rapid urbanization, construction land continues to devour high-quality land resources, resulting in deterioration of the ecological environment.In this paper, the mobile window method is used to obtain the construction land source, the economic and social factors are selected to build the resistance system, the MCR surface is generated, the natural breakpoint classification method is used to obtain the suitability partition, and the appropriate expansion path is obtained through the Hydrology expansion module in ArcGIS. The ecological isolation zone and ecological key points provide reference for the future urban construction land expansion direction and ecological construction.The results show that:①70% of the area in Nanchang belongs to the permitted construction area. For important areas that maintain the urban ecological environment, it is important to protect and take into account the common development of economy and ecology. ②Using the Hydrology expansion module to extract the features of the MCR surface in Nanchang city, it is found that the north and west of the main city are more suitable for construction land expansion. ③The key points of ecology play an important role in maintaining the urban ecological environment. In the future planning, key protection should be emphasized and development should be restricted.

Entropy weight TOPSIS model planning evaluation based on geographical conditions monitoring

MAI Jiankai, KANG Xinyi, ZHU Ziyang, ZHAO Yaolong

2019, 0(12):  122-127.  doi:10.13474/j.cnki.11-2246.2019.0400

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Taking the comprehensive evaluation of 2010 to 2015 land use planning in Doumen of Zhuhai as an example, this paper uses an entropy weight TOPSIS model based on geography condition monitoring results and land use planning data to evaluate the implementation effect of Doumen. The result showed the land use in Doumen that the trend of increasing and then decreasing the "V" shape from 2010 to 2015, and the implementation of urban and rural construction land, natural reserves, agricultural land and other land types is poor; the comprehensive evaluation score of the planning implementation was between 0.40 and 0.61, the "S" shape is changing and the total amount of ecological land is reduced, the landscape diversity is under certain pressure.

The character analysis of the fifth facade in historic conservation district, Beijing

CHEN Pinxiang, ZHANG Yiran, JIA Guangjun, TAO Yingchun, ZHU Xiaokun, ZUO Xiaogang

2019, 0(12):  128-131.  doi:10.13474/j.cnki.11-2246.2019.0401

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Historic and cultural blocks and the architectures are important historical and cultural resources, which need effective protection and utilization; as well as an integral part of the city, need to be continuous renewed and developed. This paper considers in a certain of the protection of historical and cultural blocks, taking the texture and the fifth elevation characteristics of architectures in historical and cultural blocks, within the old city of Beijing, analysis the fifth facade color and morphological characteristics of architectures, evolution of temporary architectures, etc. Strengthening the planning and control of the fifth facade elevation will play a role in protecting the historical and cultural traditions, realizing the organic renewal of the old city and improving the living environment and quality of the old city in Beijing.

Horizontal displacement monitoring technology of foundation pit based on distance convergence

WANG Dengjie, XING Zhicong

2019, 0(12):  132-136,146.  doi:10.13474/j.cnki.11-2246.2019.0402

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In this paper, with free station setting scheme, a method to monitor the horizontal displacement of foundation pit slope is established. The method needs to observe the horizontal distance between monitoring points and reference points, and also needs the convergence value of the distance. In particular, a method for measuring the deep horizontal displacement on opposite sides by using electronic total station is given. Based on the principle of equal influence and the existing information of reference points, the principle and accuracy of foundation pit displacement monitoring method and distance convergence measurement are analyzed. The difference calculation and data processing of displacement monitoring points are realized. The accuracy of two distance convergence methods for monitoring horizontal displacement is discussed and applied to actual observation. The analysis results and engineering measured data show that the observation accuracy of the monitoring method meets the specification requirements, and the measurement efficiency is high, with good application value.

Oilfield reservoir parameter inversion based on nonlinear Bayes inversion algorithms

ZHANG Xudong, FU Huanian, YANG Chong

2019, 0(12):  137-141.  doi:10.13474/j.cnki.11-2246.2019.0403

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It is of great significance for real-time monitoring of reservoir safety to use surface subsidence information to quickly acquire reservoir status information based on geophysical inversion algorithm.At present, there are few studies on reservoir parameter inversion at home and abroad. Therefore, this paper takes Panjin area of Liaohe which is a typical area of surface subsidence caused by oil exploitation as the research area,InSAR subsidence monitoring results as observation data, Okada model as inversion model, and introduces the nonlinear Bayes inversion algorithm into the inversion of reservoir parametersin oilfield for the first time.During the experiment, more than one reservoir was found in the oilfield, so the double Okada model was introduced into the inversion of reservoir parameters in oilfield for the first time.Experiments show that:(1) The nonlinear Bayes inversion algorithm can not only obtain the optimal inversion parameters, but also explain the uncertainty of inversion results. (2) Compared with the single-source Okada model, the double Okada model is more in line with the mapping relationship between reservoir parameters change and surface subsidence, and the reservoir parameters obtained from double Okada model are more reliable.

Research on the visualization of network public opinion of emergence spreading on GIS

WANG Jingquan, WANG Kai

2019, 0(12):  142-146.  doi:10.13474/j.cnki.11-2246.2019.0404

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There is urgent demand for analysis of network public opinion under the social transformation period in our country. Microblog is being increasingly investigated due to its big data features, it provides large volumes of data for discovery of knowledge about public opinion and physical environment. Once connected with their location, it provides new opportunities for geographical analysis. Analysis and data mining through microblog messages posted by users, it provides information for decision making by governments. With the help of microblog data and Using data mining in this paper, then analysis the public opinion transmission mode in spatial dimension and using geographic location information to visualize the distribution and statistic method combined to explore the propagation laws of network public opinion.

Study on compilation of government maps

DING Xuhua

2019, 0(12):  147-151.  doi:10.13474/j.cnki.11-2246.2019.0405

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Government map is a surveying and mapping geographic information product which is in great demand by government departments in recent years. This paper studies on key problems in the compilation of government map in recent years, such as the entry point of topic selection and quick database mapping. Through the analysis of the local government work reports and social issues, the author organizes the government map topic selection, combines with multi-source data such as Zhejiang exchange platform, government affairs report and collection platform, national census and so on, then uses quick mapping technology, absorb the opinions and suggestions from all aspects to compile government maps to achieve accurate and efficient service of government work.

Teaching reform of photogrammetry course in the new situation

BIAN Yuxia, SONG Hongquan, WANG Yongqian, WANG Xiaoting

2019, 0(12):  152-155.  doi:10.13474/j.cnki.11-2246.2019.0406

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With the popularization and development of video satellite, unmanned aerial vehicle and computer technology, photogrammetry technology has been widely utilized in every field of smart city construction from traditional terrain reconnaissance and mapping. It may be an inevitable trend for photogrammetry to achieve multidisciplinary cross-integration. Oblique photogrammetry and computer vision in this article are introduced to the original photogrammetry teaching, to optimize and to enrich the teaching content and the teaching practice of photogrammetry. It is necessary for photogrammetry teaching to expand related foreword knowledge to meet the needs of modern society for innovative and practical photogrammetric talents, and to provide a theoretical basis for the photogrammetry discipline to adapt to the new era.

Application of 3D mobile laser scanner in measurement of underground pipe gallery

TAN Jimeng, ZHANG Pengfei, SHAO Shicheng, LIU Xiuhan

2019, 0(12):  156-158,162.  doi:10.13474/j.cnki.11-2246.2019.0407

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Aiming at the low efficiency and poor precision of traditional underground pipe surveying methods, a new method for underground pipe gallery measurement based on 3D mobile Laser scanning technology is tested.This paper takes an underground pipe gallery beside Fudi Street in Jinan as an example, the feasible measurement scheme is worked out. The point cloud data is obtained by GEOSLAM ZEB-REVO 3D mobile laser scanner, and the data is post-processed by Trimble Realworks software. Combined with the method of total station, result shows that the 3D mobile laser scanner can significantly improve the working efficiency in the measurement of the underground pipe gallery, and can satisfy the accuracy requirements, which has a good application prospect.

Application of new mobile 3D laser scanning technology in ellipsometry of shield segments

LI Jun, GAO Tao

2019, 0(12):  159-162.  doi:10.13474/j.cnki.11-2246.2019.0408

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Monitoring the deformation of the tunnel structure during the iron operation phase to ensure the safety of the subway operation. Ellipticity detection is an important task in the detection of subway tunnel structures. This paper briefly introduces several methods of traditional ellipticity detection, analyzes the basic principle of the new mobile 3D laser scanning detection system and the method and processing flow of tunnel ellipticity detection. Through the practical application of the engineering case and comprehensive analysis of the test results, the great advantages of the mobile 3D laser scanning technology in the ellipticity detection of the segment are proved, and the development of the tunnel structure inspection industry is promoted.