Table of Content

25 January 2017, Volume 0 Issue 1

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Review of Three-dimensional Surface Deformation Acquisition from InSAR Measurements and Its Application

GAO Mingliang, GONG Huili, CHEN Beibei, ZHOU Chaofan, SI Yuan

2017, 0(1):  1-4.  doi:10.13474/j.cnki.11-2246.2017.0001

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In this paper, methods for obtaining three-dimensional deformation based on InSAR techniques in recent years are reviewed, and the development of these techniques is discussed. Important knowledge and theory are introduced simply while typical cases for each method are enumerated. Then applicable condition is summerized to provide relevant researchers of the latest research progress and technical reference.

Research Progress of Map Color Design Based on People with Color-vision Deficiency

QIAN Mengru, LIANG Dongdong, WU Xu

2017, 0(1):  5-11.  doi:10.13474/j.cnki.11-2246.2017.0002

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Based on the studies of people with color-vision deficiency at home and abroad, a systematical analysis on these literatures from the aspects of research content and method has been made in this paper. Four main aspects are found in these literatures. Firstly, scholars revel the roles of non-color's clues in people's description and recognition about color by fundamental color study. Secondly, from the people with color-vision deficiency, scholars have found their preferences are related with their color's emotion by the research on color reference. Thirdly, scholars study the system of accessible color design, combining with visual feature of people with color-vision deficiency and image conversion algorithm. Fourthly, scholars make use of the image conversion algorithm to revise the image that people with color-vision deficiency have seen to make them recognize image information.

The Characteristics and Countermeasures of Urban Underground Pipelines Informatization Under the New Situation

HE Jianglong, JIANG Yifang, HOU Zhiqun

2017, 0(1):  12-17.  doi:10.13474/j.cnki.11-2246.2017.0003

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Urban underground pipeline is an important part of urban infrastructure. To boost urban underground pipeline general survey and improve the level of pipeline scientific and informationized management level are necessany for the city's steady development. On the basis of summarizing the present situation of underground pipeline information, combining with the requirements of "Guiding opinions of the general office of the State Council on strengthening the management of urban underground pipeline construction", the thoughts that how to carry out urban underground pipeline information under the new situation and countermeasures in view of the difficult in the process have been put forward.

Research and Case Analysis of Estimation Method Based on Kalman Filtering for Geodetic Parameters from GNSS Networks

WANG Zheng, ZHOU Jian

2017, 0(1):  18-21,47.  doi:10.13474/j.cnki.11-2246.2017.0004

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Focusing on the shortcomings of traditional methods, theory and key technologies with using Kalman filtering were researched for estimating geodetic parameters from GNSS network, such as station coordinates, satellite orbits and polar motion parameters. Then the achievements were verified with days of observations from 40 globally distributed IGS stations. The results indicated that the RMS values of the difference between IGS station coordinates estimated here and that advised by IGS were 0.85, 1.1 and 1.21 cm in X, Y, Z direction respectively. The RMS values achieved in the similar way for the IGS final orbits and that acquired by extrapolating for an hour with the orbit parameters estimated here were 9.8, 8.6 and 7.2 cm. The difference between the estimated polar motion parameters and those advised by IERS were mostly within 1 mas. The results showed that the algorithm used here was precise and could be utilized to estimate the geodetic parameters from GNSS networks.

A Blind ZTD Model Based on Neural Network

DING Maohua, HU Wusheng

2017, 0(1):  22-25,52.  doi:10.13474/j.cnki.11-2246.2017.0005

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Recently, blind tropospheric zenith delay (ZTD) models have been developed rapidly since they don't require any measure surface meteorological data, giving GNSS users great convenience. Neural network technology for ZTD models based on sited measured data has made some achievements. Meanwhile, some neural network models for blind ZTD models have been built, but they have some drawbacks:it ignore the ZTD variation with the time and can only forecast ZTD. In view of these shortcomings, this paper constructs an optimization of neural network model of a blind ZTD model. Results show that the proposed neural network models can forecast both ZHD and ZWD respectively and are with good accuracy:for ZHD, BIAS and RMSE are 2.5 mm and 20.6 mm respectively; for ZWD BIAS and RMSE are 2.4 mm and 35.7 mm respectively. In this paper, the ZHD and ZWD precision of the neural network models are also with the world famous blind model- the GPT2w. In addition, compared with the GPT2w, the neural network models in this study have the biggest advantages of usage without large grid data as reserved data but just need to know when to use a trained neural network, whose characteristics provide GNSS users with great convenience.

Research and Results Analysis of Methods of GNSS Spatial Signal Time Monitoring

ZHANG Jiejun, CHEN Junping, ZHANG Yize

2017, 0(1):  26-29,92.  doi:10.13474/j.cnki.11-2246.2017.0006

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Methods using GNSS signal in space to monitor time offset among timing stations are dicussed. Three methods namely the traditional PPP, PPP with fixed station coordinates and the real-time network solutions are compared. To validate and assess the performance of SIS time offset monitoring, data of 5 GNSS stations with different configurations are analyzed.Results show that:(1)Precision of real time network solutions is 0.16 ns, which is at the same level of post-processed PPP.(2)Station coordinates estimation has impact on the determination of station clocks,which is about 0.04 ns. (3) Precision of time transfer for stations depart 2000 km could reach 0.14 ns in the real-time network solution.

Analysis of the Impact of Prismatic Sub Block Motion from the 8 Magnitude Earthquake in Wenchuan Area

YUE Caiya, DANG Yamin, YANG Qiang, HAN Xueli

2017, 0(1):  30-34,57.  doi:10.13474/j.cnki.11-2246.2017.0007

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The crustal movement in the Sichuan Yunnan region is the most active around China, which is also the hot spot of the scholars' research. Based on the GNSS continuous observation data solution (time node for the Wenchuan earthquake) in 1998-2008 and 2008-2015, combined with the previous classification scheme of the Sichuan Yunnan region prismatic block,Euler vector of each block is calculated based on the Euler vector. In this region, grid interpolation is used to retrieve the characteristics of two periods of crustal movement, and to study the relative motion of adjacent blocks by selecting a point in the vicinity of the fault zone or the fault zone.The results showed that the Wenchuan earthquake did not cause the change of the whole movement characteristics, but the movement of some local blocks and the relative motion of the adjacent blocks.

An Improved GPS Elevation Fitting Model for Different Terrain

TIAN Xiao, ZHENG Hongyan, XU Mingyuan, ZHANG Chao

2017, 0(1):  35-38,64.  doi:10.13474/j.cnki.11-2246.2017.0008

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According to the characteristics of different fitting models in GPS height fitting, a synthetic model is created which combines a better overall fitting of multi-surface function and a flexible partial fitting of movement method. The synthetic model of this paper has a better fitting effect with higher precision and more stable error comparing with other two synthetic methods in three different terrain conditions.

A GNSS Baseline Network Adjustment Method Based on Length and Attitude Measurements

BAI Zhengdong, TANG Xiaoyu, XIANG Wei

2017, 0(1):  39-42.  doi:10.13474/j.cnki.11-2246.2017.0009

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According to the fact that it takes a lot of time to obtain high precision results by single epoch algorithm, three GNSS receivers are erected on a carrier. The distance between the receivers are measured in advance, and the attitude angles of the carrier are measured by a gyroscope. Thus, the distance and attitude constraints are added to the baseline adjustment. Then a relatively stable and accurate result is achieved. The experiment results show that the maximum deviations are less than 10mm in the east and north directions, 30 mm in the elevation direction. The accuracy of the result is improved by more than 15% compared to the result without distance and attitude constraints.

Generation of Epipolar Imagery for Linear Satellite Stereo-pair Based on Parallel Features

CAO Bincai, QIU Zhenge, ZHU Shulong, SHEN Wei, CAO Bin

2017, 0(1):  43-47.  doi:10.13474/j.cnki.11-2246.2017.0010

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In view of characteristics of epipolar imagery from push-broom scanner sensors, an epipolar imagery generation method based on the parallel relationship is studied. Raw imagery is firstly divided into several blocks, then the rational function model and the projection track method are adopted to calculate the approximate epipolar lines. By analyzing the slope and fitting error of epipolar lines, raw imagery can be rotated a certain angle to generate epipolar imagery. Finally, the feasibility of this method can be examined by vertical parallax. The experimental results show that although the rotation method is not of general applicability, it is certainly feasible for WorldView-2's 4 band multispectral and pan imagery.

Comparison and Analysis of Agricultural Information Extraction Methods Based upon GF2 Satellite Images

LI Peng, YU Hu, WANG Peng, LI Kaiyuan

2017, 0(1):  48-52.  doi:10.13474/j.cnki.11-2246.2017.0011

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The study chooses 0.8 m panchromatic/3.2 m multi spectral resolution GF2 remote sensing image as the basic data. Information extraction processes and methods based upon GF2 resolution satellite images are compared and analyzed. In order to obtain spectral characteristics of different types of information, the spectrum of GF2 satellite image is analyzed. Then, the spectral and spatial information of remote sensing images are fused. Furthermore, the study compared quality evaluation of different fusion methods. Then, the study makes the agricultural information extraction experiments by using the threshold, the relationship between the spectral method, unsupervised classification and object-oriented method. The paper also verifies the accuracy of information extraction results and takes results analysis. Tests showed that Pansharp fusion algorithm was the best method among these methods, it has the advantage of normal color image, no ghost, high definition, class contrast to normal, clear texture, high entropy, high correlation coefficient of fusion images and the original multispectral images. Threshold and spectral relations method applies to extract a single element of agricultural information. Unsupervised classification method is suitable for obtaining land use in the study area quickly and preliminarily. The method of object-oriented has the high precision for whole information extracted. Overall, the different information extracted method has its own advantages. In practical, the people can select the best method according to the spectral characteristics of the class.

Remote Sensing Image Retrieval Using Bag of Visual Words Model and Color Histogram

HU Yiqun, ZHOU Shaoguang, YUE Shun, WANG Sha

2017, 0(1):  53-57.  doi:10.13474/j.cnki.11-2246.2017.0012

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Content-based remote sensing image retrieval has become a research hotspot in remote sensing field. In view of this, a new method based on this bag of visual words model and color histogram is proposed for remote sensing image retrieval. The method extracts image local invariant features with scale invariant feature descriptor, combines local features by bag of visual words model, and generates pyramid histogram for each image. Then a more distinctive feature vector is achieved by combining the color histogram of each image, the support vector machine classifier is trained using the feature vector set generated last step, and the images classified into one category with the query image then to be output through the classifier. Finally remote sensing image retrieval procedures are completed. The experimental results show that the proposed method not only improves the precision and recall of image retrieval, but also verifies that the method can efficiently overcome the changes of illumination, noise and direction, and has better robustness.

Ground Deformation over Century-long Coal Mining City Monitored through Incorporating Both PS and SBAS InSAR: A Case Study of Xuzhou

JIANG Decai, ZHANG Jixian, ZHANG Yonghong, WU Hongan, KANG Yonghui

2017, 0(1):  58-64.  doi:10.13474/j.cnki.11-2246.2017.0013

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The algorithm fusion of permanent scatterers interferometric SAR (PS InSAR) and small baseline subset interferometric SAR (SBAS InSAR) has become a hot spot of InSAR technology. By fusing the advantages of PS/SBAS, 128 ALOS PALSAR images (from 2007 to 2011) and 24 Radarsat-2 images (from 2012 to 2015) are used to extract the ground deformation field and trend in recent 8 years over Xuzhou region with century-long coal mining history. The experiment results demonstrate that:① From 2007 to 2011, four main subsidence areas have been found in Xuzhou, locating in Peixian County, Fengxian County, Tongshan District and Jiawang District. ② From 2012 to 2015, the subsidence range of Peixian County, Fengxian County and Tongshan District is expanding; however, the subsidence range and rate of Jiawang District decrease significantly. The phenomenon shows that the governance of mining subsidence in Jiawang District has achieved good results in recent years. In addition, there comes into apparent subsidence in Suining County. ③ The results of this experiment has been validated by the published research results on ground subsidence in Datun Center District, Peixian County. ④ The results represents the first-ever subsidence information in the recent 8 years in Xuzhou, which can be applied to monitor and control the subsidence in this area.The monitoring result is of high significance for monitoring and control, prevention and mitigation of ground subsidence disaster over the region.

Intelligent Remote Sensing Classification Based on Cuckoo Search Algorithm

SHEN Quanfei, CAO Min, SHI Zhaoliang, XU Ruqi

2017, 0(1):  65-68,73.  doi:10.13474/j.cnki.11-2246.2017.0014

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A new, intelligent approach to classify remote-sensing images based on Cuckoo search algorithm is presented. Cuckoo search algorithm, a new bio-inspired intelligence algorithm, is widely used to solve optimization problems. Cuckoo search algorithm to search for the optimal upper and lower threshold values on each band of remote-sensing image is applied. The classification rules are constructed by the links between the optimal split values and classification type in the explicit formation of ‘if-then’, and each link corresponds to the optimal solution of one Cuckoo, nest or egg. By taking an example of ALOS image in the north shore of the Yangtze River estuary, the proposed classification method based on CS algorithm is implemented and tested against See5.0 decision-tree method. The overall classification accuracy and Kappa coefficient of CS-based method are higher than the See5.0 decision-tree one. The results demonstrate that the practicability of applying CS algorithm to classify the remote-sensing images.

Research on Algorithms for Solving Roof Model by Using Straight Skeleton of Polygon

WANG Fei, LI Chengming

2017, 0(1):  69-73.  doi:10.13474/j.cnki.11-2246.2017.0015

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City, as an important place of human life, is the main field of 3D GIS application. A method to automatically generate the roof model based on straight skeleton of polygon is presented, with skeleton line extraction-housing model as the framework, based on 2D contour data of housing and the basic information of the roof (angle, roof height, texture attributes). At last the basic idea of the method is described and the effectiveness of the algorithm is verified by experimental results.

Global Land Cover Information Sharing Based on CSW

XU Shenglei, LI Songnian, SUN Yaqin

2017, 0(1):  74-78.  doi:10.13474/j.cnki.11-2246.2017.0016

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Metadata is one of the important technologies of information sharing. The information of land cover has the characteristics of diverse types, complex processing and fast change. There is no corresponding metadata standard specification until now. The characteristics of land cover information are analyzed in this paper. The existing GIS metadata standard is extended, and the global land cover information metadata model is constructed based on above. Combined with CSG specification of OGC, the global land cover metadata directory service sharing program is presented. At last, the prototype system of global land cover information metadata catalog is implemented, which provides users with the ability to discover, publish and manage metadata, and promotes the sharing of global land cover information.

A Fast Updating Method of Housing Digital Map and Its Implementation

TANG Jianzhi, PEI Lianlian, REN Haiying, ZHENG Yuan, FENG Xuebing

2017, 0(1):  79-82.  doi:10.13474/j.cnki.11-2246.2017.0017

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At present, the updating method of housing digital map is mostly based on basic topographic mapping, remote sensing and on-field data gathering, etc., which results in several problems such as long updating period, high costs, heavy workload, low timeliness and difficulties in change discovery. A fast updating method of housing digital map is presented, based on business data in related business process of city change, especially, spatial data of housing mapping, to require high timeliness of housing digital map, and to achieve automatic association of housing spatial information and housing transaction business data. Compared with traditional updating methods of housing digital map, this method has the characteristic of low cost, high accuracy, high timeliness. Presently, it has been applied into the construction of Beijing housing-life-cycle management information platform, and efficiently realized the automatic updating of housing digital map.

CityEngine Based 3D Campus Parametric Fine Modeling

ZHAO Yuqi, MOU Naixia, ZHANG Lingxian

2017, 0(1):  83-86,111.  doi:10.13474/j.cnki.11-2246.2017.0018

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3D fast fine modeling based on the existing 2D data is an important research direction in the current field of GIS. In this paper the procedures and methods of CityEngine parametric modeling by rules are presented, the rules function prototype and effects are introduced, and the procedures of 3D fine ruling modeling on buildings, roads, vegetation and water areelaborated.An entire 3D campus scene on CityEngine platform is built b taking the Shandong University of Science and Technology as example.Parametric modeling can change the specific features of modelsby adjusting the parameters, realize the real-time dynamic 3D modeling, and make up the shortcomings of traditional modeling methods. It is significant for 3D rapidly large-scale urban fine modeling.

An Improved Algorithm for Fast Map-matching of Floating Car

ZHANG Jianqin, LI Mingxuan, DUAN Yingchao, DU Mingyi

2017, 0(1):  87-92.  doi:10.13474/j.cnki.11-2246.2017.0019

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Floating car map-matching algorithm enables fast and accurate matching between the discrete points of floating car and the road segments. It is the core part of floating car traffic information generation technology. For the deficiencies of the prior method, an efficient logical matching method is proposed and implemented. Firstly it establishes buffer zones with effective threshold for the anchor points, and then searches the road segments that intersect with the buffer zones. After that, it discriminates the driving track by four parameters(driving speed, driving direction, projection distance and driving distance). The experiments show that this method does not require extensive work to deal with road network data. It simplifies the process of searching candidate matching road segments and ensures matching accuracy while also shows a higher efficiency.

Application and Precision Analysis of Tight Coupling Direct Georeferencing Method

CHEN Jie, LI Jing, DU Lei, HAN Yachao

2017, 0(1):  93-96,111.  doi:10.13474/j.cnki.11-2246.2017.0020

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The direct georeferencing method, based on airborne POS-supported system, provides mean square errors with the plane and elevation less than 10 and 15 cm respectively. However, to achieve such precision, the airborne data acquiring process has to meet a series of relatively strict standards. The tight coupling direct georeferencing method that based on virtual reference station and inertially-aided real time kinematic overcomes the restrictions on the flight conditions and the base station distance. Even in the case of satellite unlock, ground base station distance over 70 km and no base station, it can still obtain the results met the accuracy.This paper adopts the tight coupling direct georeferencing method to carry out the high-precision digital aerial remote sensing application in urban Shenyang city, Liaoning Province, China. Results show that the accuracy of the data obtained by the airborne POS based on tight coupling scheme is better than that of the loose combination.And the results obtained by the tight coupling precise point positioning solution can also meet the relevant standards.

Development of RTK Measurement System Based on BD930 Board

CHANG Yi, WANG Liang, HUANG Jinsong, SHI Xiaoqi, FENG Gengxu, WU Jianhua

2017, 0(1):  97-101,105.  doi:10.13474/j.cnki.11-2246.2017.0021

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Geophysical survey often encounters adverse environment jungle, canyons, narrow ditch and so on. This results in the number of visible satellites reducing and unstable satellite signal. Then it causes the accuracy of the positioning results decrease, working efficiency reduce and so on. Towards this problem,the use of multi-system compatible and highly sensitive BD930 board as the receiver main board is proposed, and the control method of the board is showed. In addition,a set of real-time kinematic positioning hand-book software is developed, and the differential data chain is built through network communication technology. Tests on the performance of the whole measurement system under actual geophysical survey work environment are completed. Results show that to some extent the system improved the ability of RTK to adapt to different environments, the differential data chain built up makes the measurement operation more convenient and efficient, and the needs of engineering application can be met.

Impact Analysis of Ionosperic Delay on GPS Network Surveying of the Urban Rail Transit

WANG Sikai, LI Guan, MA Quanming, XIONG Qizhi

2017, 0(1):  102-105.  doi:10.13474/j.cnki.11-2246.2017.0022

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In this paper, the GPS network of Nanning rail transit is adopted as an example. The relative ionospheric model is adopted in consideration of the ionospheric activity in Nanning. The short period variation of the ionospheric delay in each station is analyzed, compared with the values release by the authoritative organization. Some conclusions are made finally.

Monitoring and Prediction of Railway Deformation based on DInSAR and Probability Integral Method

ZHENG Meinan, LIU Yixuan, DENG Kazhong, ZHAO Chenliang, FENG Jun

2017, 0(1):  106-111.  doi:10.13474/j.cnki.11-2246.2017.0023

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In order to obtain real-time dynamic deformation and deformation trend of railway above goaf,a method based on the combination of the Differential SAR Interferometry (DInSAR) technique and probability integral method was presented in this paper. Firstly,the DInSAR technology was used to monitor the goaf,and the monitor results were compared with leveling data.Then,the probability integral method parameters were calculated using DInSAR monitoring results, and modified the prediction parameters into sufficiency mining condition.Finally, the deformation of the railway was predicted using the modified parameters. The results verified the combination of both can effectively monitor and predict railways and other linear structures.

Study on Complex Shaped Building Measurement Based on 3D Laser Scanning System

CUI Lei, ZHANG Fenglu, QIAN Lin

2017, 0(1):  112-114,143.  doi:10.13474/j.cnki.11-2246.2017.0024

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In order to improve the operational efficiency and the results quality of the complex shaped building, a measuring method of the CCTV new site building based on 3D laser scanning system is designed and implemented. First, the principle and the integrated operational procedures of the 3D terrestrial laser scanning system are presented. Then, three-dimensional model of the CCTV new site building are measured and reconstructed. Finally, accuracy evaluation is accomplished by measuring the plane reflective targets based on scanning system and total station, as a reliable basis for measuring and analyzing the complex shaped building.

Anslysis of Improving Subway Tunnel through Survey Precision

CHENG Shu, WU Guangyao, JI Ping

2017, 0(1):  115-118.  doi:10.13474/j.cnki.11-2246.2017.0025

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Three improvement measures for improving the accuracy of the subway tunnel through survey was adopted in a practical case and analyzed the observation data. The results demonstrated that these measures could improve the accuracy of the subway tunnel through survey.The improvement measures are as follows:The CORS is adopted as satellite positioning control network starting basis. Suspension atilizes three wire method and double measuring method to increase the check condition by connection surveying. The accuracy of the underground traverse with the high precision gyroscope and the detection of the nuclear underground wire is presented in the appropriate position.

Practice and Exploration of Geographic National Census Results Application

HONG Liang, YU Xiaomin, SHI Xiaoming

2017, 0(1):  119-121,129.  doi:10.13474/j.cnki.11-2246.2017.0026

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The connotation, significance, results and products of geographical national census and monitoring were analyzed in this paper. And in view of the current hot spots, the application of Geographical National Census results was explored. It lays a good foundation for the establishment of the new development direction of geographic information sector.

Design and Implementation of a New Cross-platform Open Source GIS Desktop Software

CAI Wenwen, WANG Shaohua, ZHONG Ershun, HU Chenpu, LIU Xiaoni

2017, 0(1):  122-125.  doi:10.13474/j.cnki.11-2246.2017.0027

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Requirements for open source and cross platform GIS software are increasing in China. But there is still no open-source cross-platform professional desktop GIS software at present. To meet the requirements, SuperMap iDesktop Cross, an open source and cross platform desktop GIS software, is designed and implemented based on OSGi framework. It consists of GIS core library developed by C++ programming language and user interface developed by Java programming language. SuperMap iDesktop Cross provides functions of data management, data processing, 3D visualization, spatial analysis and API for customization development. It can be used not only on windows operating system for personal computers, but also on Linux and UNIX for servers and high-end servers, which will broaden and deepen the application and development of professional GIS software.

A Method of Terrain Area Calculation in Considering of Slope Factors and Extreme Value

CHENG Chuanlu, JIANG Guangwei, TIAN Xiaojing, MA Xinying, WANG Wenli

2017, 0(1):  126-129.  doi:10.13474/j.cnki.11-2246.2017.0028

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In connection with the effection of the local terrain slope factors and extreme value to terrain area calculation, a new method that considering of slope factors and extreme value is proposed. The surface area theory and errors are analyzed. Finally the typical two region's data of west China are used experiment analysis. The results indicate that the algorithm enhance the terrain fitting, on the macro, the graphic property is similar with the regular grid of cross-diagonal method. The deduce area errors formula indicated that the terrain surface area calculation is more reliable in considering the slope factors and extremevalue.

Scale Adaptability of Raster Intermediate Layer in Terrain Analysis

ZHANG Lichao, ZHAO Peng, ZHANG Hechao

2017, 0(1):  130-133,138.  doi:10.13474/j.cnki.11-2246.2017.0029

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Raster intermediate layer is fundamental and reusable raster layer for terrain analysis created by the DEM, DSM, vector data, which is obtained through a series of raster calculation. The scale adaptability of raster intermediate layer is studied. The range, scale, resolution, analysis are defined. The principle of range, scale, resolution are determined. Particularly, the paper takes the experiment of scale adaptability of the tangent, curvature raster intermediate layer aiming at the analysis scale, and puts forward the adaptive algorithm and analysis scale. The result shows that raster intermediate layer of terrain foundation factors created from this solution meets the need of numerical precision and morphology precision for terrain analysis.

Development and Application for Visualization Early Warning System of Urban Underground Pipelines about Water Quality

WANG Zicheng, YANG Shuowen, CHEN Yajun, XU Houlei, WANG Guobin

2017, 0(1):  134-138.  doi:10.13474/j.cnki.11-2246.2017.0030

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In view of the complexities of urban underground pipelines and the insufficient level of information about the part of pipelines for water quality monitoring, the visualization early warning system of urban underground pipelines about water quality has been developed with the SuperMap which has the powerful three-dimensional graphics capabilities. In this system, the three-dimensional visualization of the scene, the pipes model, the monitoring results and the SuperMap system were combined together, and the three-dimensional scene of urban underground pipelines was built visually and effectively. The information of visualization model can be displayed dynamically and queried interactively in real time. Meanwhile, the system automatically identifies abnormal index value of monitoring instruments by setting up the thresholds of water quality monitoring indicators, and pushes abnormality information to monitoring persons, so as to achieve the purpose of monitoring and early warning. Therefore the system provides an intuitionistic and interactive visualization management and security control platform for urban underground pipelines, which has some practical meaning and application values.

Research on the Method of DLG Production with DEM

WANG Yuan, LIANG Tao

2017, 0(1):  139-143.  doi:10.13474/j.cnki.11-2246.2017.0031

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This paper focuses on the geomorphic feature extraction based on DEM while inuestigates its accuracy evaluation methods, principles and typical algorithms of terrain feature extraction on DEM. Furthermore, it summaried the technical characteristics of the DLG's production using DEM data, designed processes and conducted a production test. Tests show that DLG production with DEM can meet the needs of basic contour interval greater than 2 meters, the scale less than 1:2000 DLG production in the case of high-resolution DEM data, which can be used as a complementary technology of photogrammetry.

Research on the Method of Measuring Instrumental Height in High Precision

WANG Tao, TIAN Linya, WEI Yuming, WU kun

2017, 0(1):  144-146,160.  doi:10.13474/j.cnki.11-2246.2017.0032

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Demands of various engineering on measuring accuracy are higher and higher, The first program in surveying and mapping is measuring instrumental height, the precision of measuring instrumental height will determine the overall precision of the measurement field. This paper introduces the common methods of measuring instrumental height, and makes local changes to tripod and matches a new design of a ruler. In the end, it puts forward a new method of measuring instrumental height, which is simple in operation and have good feasibility. In addition, it can improve the accuracy of measuring instrumental height and gain high popularity. In this paper, the idea provides a new reference for measuring instrumental height in measurement field and provides a new idea for improve instrument.

Research and Implementation of Network Support System for China Border Mapping Geoinformation

XIANG Huili, ZHANG Peng, ZHANG Yanming, DONG Dechao

2017, 0(1):  147-150.  doi:10.13474/j.cnki.11-2246.2017.0033

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In the task of mapping the topographic maps with neighboring countries` borders in various scales, there must be border elements to deal with. Particularly when the scale is greater than 1︰1 000 000, border elements need to be signed in more details according to the bilateral agreement and the protocol map. Based on the realistic needs and the geography information data of multi-scale, multi-projection and multi-storage format, the proposed system realized the one-stop services of digital management and network sharing for China boundary topographic data using the multi-source data fusion and the tile pyramid technology.

Design and Development of Electric Power GIS Data Acquisition System

CHEN Liang, WANG Jianfeng, SHAN BaoLin, XIE Weiguang, WANG Binghui

2017, 0(1):  151-153.  doi:10.13474/j.cnki.11-2246.2017.0034

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In order to improve the working efficiency of the grid GIS data acquisition, ensure the integrity, accuracy and timeliness of the power grid GIS platform of spatial data and attribute data, the electric power GIS data acquisition system is successfully developed, using the modern Ntrip network RTK technology, mobile GIS technology, database technology and RFID identification technology. Practical engineering application shows that the system improves the efficiency of the collection, which can effectively meet the needs of the grid GIS collection work.

Curriculum Teaching Study of GNSS Measurement and Application under Engineering Professional Accreditation

JIANG Tingchen, WANG Xiuping, JIAO Minglian, ZHOU Li, DONG Chunlai, WANG Jigang, LI Weixiao

2017, 0(1):  154-156,160.  doi:10.13474/j.cnki.11-2246.2017.0035

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Engineering education professional accreditation is a kind of conformity assessments, which is different from the undergraduate assessment and review. Getting the certification means that all students meet the graduation requirements. At present, many professional colleges is to accept the engineering education accreditation, of course, surveying and mapping engineering education professional accreditation is no exception. In this instance, this paper first reviews the current status of the national professional certification, and expounds the construction of professional curriculum system of surveying and mapping engineering education accreditation. Results oriented teaching design process of the specialty of surveying and mapping of education is analyzed, at the same time, the course syllabus of GNSS measurement and application is modified and improved. In the end, it is studied how to reflect the core concept of engineering education accreditation in the course of classroom teaching, and some examples are discussed.

Teaching Practice of Automatic Collinear Equation Linearization Using Mathematica

BEN Jin, YANG Chunyu

2017, 0(1):  157-160.  doi:10.13474/j.cnki.11-2246.2017.0036

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Imaging equation of central projection, which is usually called collinear equation, is the theoretical basis of photogrammetry. Collinear equation linearization is the premise to build the mathematic models of photogrammetry adjustment, so it is of great importance for beginners to grasp the fundamentals of analytical aerial triangulation. Artificial linearization is of heavy workload, easy to get wrong and boring. In view of this, automatic linearization scheme using Mathematica is designed. Practice shows that this scheme is easy, correct and flexible and it can help beginners master the skills of linearization quickly with great teaching efficiency. Ideas and methods mentioned in this paper also explore an effective way for promoting teaching quality of specialized courses and facilitating educational reform.