Table of Content

25 August 2020, Volume 0 Issue 8

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Automatic extraction of impervious surface information in Nanchang

HE Jiajun, LIU Xiangtong, TU Liping, XU Kan, HE Ziling, SONG Haohang, LIU Huan

2020, 0(8):  1-4.  doi:10.13474/j.cnki.11-2246.2020.0238

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With the accelerating urbanization process, impervious surface has become one of the most important types of surface coverage. How to obtain impervious surface information with high-precision quickly has become an important question in remote sensing. Considering the complex structure and spectral curve of the impervious surface, based on the idea of decision tree, using built-up area index (BUAI) and modified normalized difference water index (MNDWI), this paper makes the mask of vegetation and water in study area. Then, the characteristics of soil reflectance spectrum are utilized to make soil mask. Through the extraction model based on the idea of decision tree, combined with the mask file, the permeable surface objects are removed step by step, and the impermeable surface are obtained. The results show that the overall accuracy of the impervious surface extracted by the model is 98.27%, and the Kappa coefficient is 0.86. Compared with the investigation of the study area, the consequences are believed to be more reliable. It is suitable for the extraction of impervious water surface information in large areas.

Analysis of the potential of GF-6 WFV data for forest and non-forest land identification

LIU Daichao, LI Xiaosong, LI Xiangchen, YANG Guangbin, YANG Junting

2020, 0(8):  5-12,17.  doi:10.13474/j.cnki.11-2246.2020.0239

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In order to study the recognition contribution of the first GaoFen (GF-6) with red edge band in China on forest and non-forest land, this paper selectes Huangshan city, Anhui province, as a research area, and adopt feature optimization (RFE). The method combined with random forest (RF) has carried out research on the identification potential of forest and non-forest land. First it builds a sample database based on field surveys, Google Earth images, and forest land "one map" sample data. Then, it classifies based on characteristics such as DEM, multitemporal spectral features, vegetation index, red edge index, and compares the accuracy of different models and the importance of different variable. The results show that the red edge information of GF-6 is more important for the identification of forest and non-forest land. The introduction of red edge information can improve the overall classification accuracy by 2%. Compared with single-phase data, the use of data can improve the classification accuracy of forest types by 2.93%~4.1%. The single-phase classification results are the best in June, the second in September, and the worst in December. The preferred features can effectively reduce data input Dimensions (46 to 15), and achieve the highest classification accuracy. It does not sacrifice accuracy while ensuring a reduction in the amount of computing data and clarifying the contribution of different variables, which has strong application significance.

Forest survey and spatio-temporal analysis in West Tianshan mountains supported by Google Earth Engine

SHAO Yakui, WANG Lei, ZHU Changming, FANG Hui, ZHANG Xin, HUANG Duan, TAO Li

2020, 0(8):  13-17.  doi:10.13474/j.cnki.11-2246.2020.0240

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Aiming at the problems of difficult data acquisition, low calculation efficiency, large amount of data and low accuracy in large-scale spatial distribution information extraction and long-time series change monitoring, supported by the Google Earth Engine platform, based on multi-source remote sensing data, a multi-dimensional classification feature set is constructed, and the forest extraction and classification of West Tianshan mountains in 1995, 2000, 2005, 2010, 2015 and 2018 are studied by random forest classification algorithm. Six periods of forest high-precision extraction and mapping analysis are completed by cloud-local combination. The results show that the process constructed in this paper has high accuracy. During the past 23 years, the forest area in West Tianshan mountains has been expanding dynamically, increasing from 3 953.57 km² in 1995 to 4 243.41 km² in 2018, with an increasing rate of 12.60 km²/a. In terms of time, the growth rate of forest has been rising steadily in the past 23 years. The growth rate in 2005-2018 is higher than that in 1995-2015. In terms of spatial distribution, there are few conversions between different forest types. The newly added forest land mainly comes from non-forest land. The area of non-forest land converted to forest land has been about 520 km² in the past 23 years. The Tex county branch, Nileke country branch, Zhaosu county branch, Xinyuan forest farm, Gongliu branch, and Yining branch have transferred areas of 111.14, 102.19, 67.16, 56.45, 42.76, and 40.71 km².

Uncontrolled positioning of large-scale image with reference to geographic data

LIU Yan, YANG Shuwen, XUE Li, ZHAO Lijiang

2020, 0(8):  18-22,27.  doi:10.13474/j.cnki.11-2246.2020.0241

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Aiming at the problems of low efficiency and high cost of acquiring control points manually by traditional photogrammetric image positioning, this paper proposes a method for uncontrolled positioning of large-scale images with reference geographic data. Firstly, it uses the classic SIFT algorithm to extract feature points with control information from the reference geographic data (DEM and DOM). Secondly, it registers DSM obtained through POS to geographic coordinates of DEM, which is morphologically filtered in order to extract and remove the matching points in areas where the elevation changes drastically due to buildings, trees and so on,so as to reduce the correction error. Finally, it corrects and locates the image. The experiments show that the proposed method in this paper can meet the positioning accuracy requirements of large-scale aerial image production. Also, this method shows the advantages of efficient production and resource saving.

GNSS dynamic monitoring model design for arm-tip of construction tower crane

ZHOU Mingduan, ZHANG Wenyao, MA Bohong, FU Jinghongyi, LUO Dean

2020, 0(8):  23-27.  doi:10.13474/j.cnki.11-2246.2020.0242

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In view of the disadvantages of traditional manual periodic inspection, a dynamic monitoring model for arm-tip of construction tower crane based on satellite positioning is proposed. Taking GPS for example, the single-epoch fast positioning model is built. The flowchart of fast integer ambiguity resolution algorithm based on DUFCOM and DC algorithm is given. And a construction method of monitoring parameters and early-alarm parameters of vertical-deviation for arm-tip based on location-deviation of epoch is proposed. The preliminary experimental results show that the horizontal-RMS is better than 2 cm and the vertical-RMS is better than 4 cm via GPS single-epoch fast positioning model. Based on the positioning results, the feasibility and effectiveness of the proposed model are verified from the monitoring parameters and early-alarm parameters.

Building fine modeling based on multi-source point cloud data fusion

WANG Shuzhen, ZHENG Guoqiang, WANG Guangsheng, HU Yumin, ZHANG Dehuai, QI Wei

2020, 0(8):  28-32,38.  doi:10.13474/j.cnki.11-2246.2020.0243

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The 3D modeling technology can realize the digital archiving of buildings and play an irreplaceable role in the protection and restoration of ancient buildings, the planning and reconstruction of modern buildings. Aiming at the problems of building models in oblique photogrammetry and 3D laser scanning modeling, this paper proposes a fine modeling method of building based on the fusion of obligue photogrammetry and 3D point cloud model generated by 3D laser scanning. Uav and 3D laser scanner are selected as experimental equipment. Point cloud stitching, production and editing are completed by ContextCapture and SCENE software. Point cloud fine matching is completed by ICP algorithm. And multi-source point cloud data fusion modeling is realized. Compared with the single modeling method model, the quality of the fusion modeling model is evaluated from the two aspects of texture structure and model accuracy. The results show that the fusion model has clear texture and intact geometric structure, and the mean error of the median distance and the mean error of the height difference of the model are both lower than that of the oblique photogrammetry model, which is close to the 3D laser scanning model.

A visual servo robot for pose estimation

HU Jianlang, LUO Yarong, GUO Chi

2020, 0(8):  33-38.  doi:10.13474/j.cnki.11-2246.2020.0244

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In order to solve the problem of people's non-standard pose and unsupervised guidance, a visual servo robot for pose estimation is designed in this paper. The robot tracks the moving target through a target tracking algorithm with attention mechanism, and works with the robot's servo motor structure to adjust the camera angle, so as to track and record the moving target in a specific area. Then, the target pose is extracted by robot's pose evaluation system and compared with the standard pose. It has been verified that the robot has a high degree of discrimination of the quality of the human pose, and can effectively evaluate the user's pose, so as to achieve the purpose of sports assistance and rehabilitation training guidance.

Augmented reality tracking registration combined with image enhancement and recovery

GUO Shixiang, FAN You, FAN Chong

2020, 0(8):  39-43,64.  doi:10.13474/j.cnki.11-2246.2020.0245

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Tracking registration technology in augmented reality has always been the focus and difficulty of research. However, the lowlight of underground mines and roadways resulting relatively dark image,and the on-board camera moving quickly and jitter,which challenge the traditional tracking registration based on feature matching. Starting from improving the robustness and accuracy of tracking registration in augmented reality, an improved method based on Retinex is used to enhance the brightness of dim images, and an adversarial neural network-based method is used to restore motion-blurred images. First, image ORB features is extracted to achieve initialization, and then the image enhancement and image restoration thread are started according to the number of tracked feature points to improve the quality and number of feature point extractions. Experimental results in the data sets and real simulation scenarios show that the tracking accuracy is improved by about 12%, and the robustness of tracking registration is also significantly improved in the case of low brightness and slight blur.

Perceptual Hash algorithm for GF-2 image using SIFT and SVD

WANG Hao, ZHANG Liming, MU Haowei, ZHANG Xingang, CHEN Jinping

2020, 0(8):  44-49.  doi:10.13474/j.cnki.11-2246.2020.0246

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A perceptual Hash algorithm for the GF-2 image is proposed to solve the problem of the local tampering in the transmission, storage and use of the GF-2 image. Firstly, the entire image is divided into multiple sub-blocks by means of fixed partitioning. SIFT operator is used to extract the feature information of key points in sub-blocks. Then, SIFT key feature information is extracted via SVD and the first 10% of them is chosen to construct the perceptual hash of sub-blocks. Finally, the perceptual Hash sequence of all sub-blocks is concatenated to generate the perceptual hash sequence of the whole image. In the process of image authentication, the difference between the original GF-2 image and the image to be authenticated is used for authentication of the content. In the meantime, the algorithm has realized detection and location of the object tampering in the GF-2 image. Experiments show that the algorithm is robust at the operation of LSB watermark embedding, DAT format conversion and BMP format conversion. In a word, the proposed algorithm can improved security for the use of the GF-2 image.

Mixed LS-TLS surface fitting in point cloud filtering

JI Wenlai, RUI Ming, LI Mingfeng

2020, 0(8):  50-54,91.  doi:10.13474/j.cnki.11-2246.2020.0247

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Aiming at the problems of the discontinuity of the fitted surface, the unreasonable parameter solution and the unclear threshold of the height difference in the process of point cloud filtering, a method for constraint surface fitting based on mixed LS-TLS (least squares-total least squares) is proposed. The multi-scale grid is constructed based on the weighted slope value of the center grid, the criteria for selecting the ground seed points based on the grid neighborhood is discussed, and the methods and steps for solving the mixed LS-TLS surface equation and adjusting the height difference threshold according to the filtering result are analyzed. Experiments show that the precision of point cloud filtering in complex regions is improved and benefit for the generation of digital elevation model.

An accurate UAV image matching based on essential matrix

GE Yipan, WANG Xiaohong

2020, 0(8):  55-58,75.  doi:10.13474/j.cnki.11-2246.2020.0248

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Unmanned aerial vehicle (UAV) images have been widely used for their low cost, easy access, and large amount of information. Image matching is an important research topic because the commonly used image matching methods often mismatch or eliminate a large number of matching pair. LMeds algorithm is more stricter than other robust method. The essential matrix obtained by "5-point algorithm" can be used to match point-pair coplanar scenarios. This paper uses the essential matrix, which is solved using the LMedS algorithm combined with the "5-point algorithm", as the model to culling the error. At the same time, the ORB method with the attributes of fast featuring characteristics is used to construct a precise and efficient matching method. The experimental result shows that the proposed algorithm retains a large number of uniformly distributed matching pairs. This method is fast and accurate with efficiency and can be applied in various scenarios.

Application of variational mode decomposition and energy entropy in denoising of geocentric motion

WANG Qingyu, DU Ning, WANG Li, ZHANG Xiaodong, WU Lei, AO Xiao

2020, 0(8):  59-64.  doi:10.13474/j.cnki.11-2246.2020.0249

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In order to solve the problems about the noise of geocenter motion time seris, such as the complex types, strong randomness, and difficult to effectively separate from the signal and so on, the net translation method is used to process the weekly solution data from IGS station, which acquires the time series of geocenter motion from 2012 to 2018, and proposing a noise reduction method based on VMD and energy entropy. Firstly, the time series components from high frequency to low frequency in each direction are obtained by decomposing the time series of geocenter motion. Secondly, the energy entropy of each variational modal component is calculated to obtain the boundary between noise and signal. Then the signal component is reconstructed to obtain the time series of geocenter motion after noise reduction.Finally, comparing EMD and EEMD methods, it is shown that the method used in this paper has better effect on noise reduction from correlation coefficient, signal-to-noise ratio, residual energy percentage, variance contribution rate and other parameter evaluation indexes.

A novel rapid initial alignment algorithm for vehicular low-cost MEMS gyroscope

BAI Zhengdong, XIN Haohao, CHENG Yuhang, CHEN Bobo, LI Qi

2020, 0(8):  65-70.  doi:10.13474/j.cnki.11-2246.2020.0250

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In vehicle navigation system, the global satellite navigation system (GNSS) is commonly combined with inertial measurement unit (IMU) to improve the system stability. Due to the limitation of application scenarios, there is a higher requirement for the initial alignment speed in vehicle navigation systems. In order to improve the speed of initial alignment algorithm for low-cost micro-electro-mechanical system (MEMS) gyroscope used in vehicle navigation system, and reduce the calculation capacity, this paper puts forward a new method for MEMS gyroscope initial alignment based on network real time kinematics (RTK) assistance and unscented Kalman filter (UKF). Based on the features of vehicle navigation, it is simplified the gyroscope error model and analyzed the error caused by the simplification. The algorithm is tested on the vehicle navigation system composed by NovAtel ProPak6 GNSS receiver and NovAtel IMU-IGM-S1. Using heading angle calculated by dual-antenna GNSS receiver as ground truth, the proposed algorithm can be finished in 5 s and the heading angle accuracy is 0.3°.

Evaluation on the precision of different BDS ionosphere model

ZHOU Jinning, ZHAO Qile, HU Zhigang, CAI Hongliang, ZHOU Renyu

2020, 0(8):  71-75.  doi:10.13474/j.cnki.11-2246.2020.0251

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At present, BDS broadcasts a variety of ionospheric model parameters, which causes the following confusion when users use it:①Different satellites may broadcast the same ionospheric model with different values in the same interval. ②The klobuchar model broadcast respectively by BDS-2 and BDS-3 are quite different. ③How to select the proper model from the three types of ionospheric model (BDS-2 Klobuchar、BDS-3 Klobuchar、BDGIM) that can be received at the same time. To propose a solution overcoming current shortcoming, this paper firstly proposes the maximum voting strategy to reasonably combine the parameters of the ionosphere models in the same calendar but with different values. Then, based on the ionosphere products of IGS analysis center, the accuracy of three BeiDou ionosphere model is analyzed and compared. Finally, the validation analysis is carried out based on the user equivalent range error(UERE). The results show that although the model values of BDS-2 Klobuchar and BDS-3 Klobuchar are quite different, the accuracy of the model is very close. Besides, the accuracy of BGDIM model is the highest, with 10% improvement compared with BDS-k8 model in the middle and low latitude area, and 61% improvement in the polar regions.

Correction of system bias between large-area GNSS leveling and gravity field model

CHEN Jianhua, WEI Dehong, ZHANG Xingfu, LI Weichao

2020, 0(8):  76-80.  doi:10.13474/j.cnki.11-2246.2020.0252

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Large-area GNSS leveling data is important independent data sources for estimating the accuracy of the gravity field model. Generally, the system bias is caused by the geoid difference between the large-area GNSS leveling and gravity field model, which has an effect on estimating the accuracy of the gravity field model by directly using GNSS leveling data. Taking the 24 152 US GNSS leveling data to estimate EIGEN-6C4 model as an example, this paper proposes to use the divisional constant system bias correction method and the four/five/seven -parameters correction method to correct the system bias between GNSS leveling and gravity field model. The results show that the system bias can be determined and effectively corrected by using the correction method of the bias of the constant system and four/five/seven-parameters method. After correcting the system bias, the accuracy of 2160 degree EIGEN-6C4 model in the US is better than 10 cm.

Digital fingerprint algorithm for vector spatial data using GD-PBIBD coding

CHEN Jinping, ZHANG Liming, JIANG Meirong, WANG Hao

2020, 0(8):  81-86,100.  doi:10.13474/j.cnki.11-2246.2020.0253

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Aiming at the difficulty of tracking traitors and low coding efficiency about fingerprint for vector map data, a fingerprint algorithm using GD-PBIBD code is proposed in this paper. Firstly, the fingerprint codes are generated by using the GD-PBIBD, also the fingerprint is shuffled by using the Logistic map before embedding. Then, the feature points of the vector map data are extracted by using the D-P algorithm, and the phase coefficients and amplitude coefficients are obtained by performing DFT transformation on the feature points. The QIM method is used to embed the fingerprint into the amplitude coefficient of the DFT transform domain, and the DFT inverse transform is implemented to obtain the vector map data containing the fingerprint. The experiment selected some Chinese road network and a certain area data in green space. After the fingerprint was embedded in the algorithm, linear and nonlinear simulation attacks were carried out. The fingerprint sequence was successfully extracted and the collaborators were tracked by Hamming distance. The algorithm has a simple coding structure. When the code length is fixed, it can accommodate more users than the BIBD code, and the efficiency is high. The algorithm is robust against single-user fingerprint attacks and multiple attacks, and can resist multi-user minimum and the maximum and minimum attacks, which track all traitors, can be used for vector map data copyright protection, provide a basis for vector space data traitor tracking.

Application of InSAR technology in auxiliary identification of expressway disasters

XIONG Peng, ZUO Xiaoqing, LI Yongfa, XIE Wenbin, YOU Hong, WANG Zhihong

2020, 0(8):  87-91.  doi:10.13474/j.cnki.11-2246.2020.0254

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In order to discover and identify hidden danger points of disasters as early as possible, this article takes the Kunming-Yuxi section of Kunmo expressway as an example. Firstly, based on PS-InSAR technology, and using 45 Sentinel-1 images to obtain the settlement rate map of the study area from 2018 to 2019. Then we use the method of cross-section analysis to analyze the serious settlement area, and identify the hidden trouble sections along the Kunmo expressway. Finally, this article makes some suggestions to further monitor these road sections. Studies have shown that the Kunming expressway generally shows a relatively gentle settlement trend, but there are three severe settlement areas. They are the sections in Xiejing village and Zhujing village, the junction of Kunmo expressway and Dongraocheng expressway, and the junction of Kunmo expressway and Jinxin highway. It prove that PS-InSAR technology can effectively detect hidden hazards along the highway.

Automatic seamline selection assisted by airborne LiDAR

LI Junping, DING Yazhou, FENG Fajie, CAI Ping, LIU Xinyi

2020, 0(8):  92-95,116.  doi:10.13474/j.cnki.11-2246.2020.0255

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An automatic orthophoto seamline selection method assisted by LiDAR is proposed in this paper. The LiDAR point cloud is used to generate DSM and DEM, the difference between which is used to obtain the difference map to represent the true height of the object. The threshold is adaptively set to divide the difference map into different regions, and different weights are given to guide the automatic selection of the seamline based on Dijkstra algorithm. The experimental results demonstrate that the proposed method is robust to the selection of parameters and the final seamline can successfully bypass the obstacles.

Three-dimensional encryption of different processing software for drone tilt photography data

YANG Wenfu, WANG Guanjie, LI Guofeng, CUI Yuzhu, WANG Wenwen, ZHANG Wenkai

2020, 0(8):  96-100.  doi:10.13474/j.cnki.11-2246.2020.0256

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Taking the ancient Great Wall of Shahukou in Youyu county, Shanxi province as an example, data acquisition is completed by using Trimble UX5 HP with Sony A7r camera, 3D reconstruction is carried out by using Context Capture software and PhotoMesh software, and 3D model is fine treatment by using Geomagtics software. Comparing the three-dimensional accuracy of the two softwares, the three-dimensional accuracy of Context Capture software is higher. At the same time, the model accuracy of Context Capture software is calculated by using the field survey checkpoints. The mean square error of the points is 0.192 m, which shows that this method can meet the requirements of real 3D model building and provide a strong data guarantee for the construction of smart city.

CVA multi-scale remote sensing image change detection combined with feature selection

CAI Fusheng, XIANG Zejun, CAI Heng, SHAN Deming

2020, 0(8):  101-104,130.  doi:10.13474/j.cnki.11-2246.2020.0257

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Aiming at the problems of the object-oriented method can not detect the subtle changes in the image, the segmentation effect, and the high false alarm rate in the pixel-oriented method in the multi-temporal change detection. In this paper, a combined with multiple characteristics change vector analysis (CVA) method based on pixel and multi-level segmentation joint discriminant method based on the object. Firstly, the spectral and texture features of different time phases are extracted, and the maximum correlation minimum redundancy (mRMR) algorithm is used to select the features and the pixel-level change detection results are obtained by CVA. Then the two images are superimposed and split, and the regional merge strategy is used to make different scale detection, obtain the test results of each scale. And finally combine the multiple test results to determine the final change test results. The experimental results show that the proposed method can effectively reduce the missed detection rate and improve the accuracy of detection.

Discussion on the application of river-lake delimitation survey: taking Liaocheng river and lake water conservancy project as an example

ZHOU Changzhi, CHEN Ruicong, LI Tao, YUAN Qingzhong

2020, 0(8):  105-107.  doi:10.13474/j.cnki.11-2246.2020.0258

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The delimitation of the management of scope rivers and lakes and the management scope and protection of water conservancy projects is to further promote the transformation from "famous" to "real". The rivers and lakes and water conservancy projects in various counties is massive, wide coverage and complicated historical problems. So it is hard to work out. By analyzing the current problems of river and lake demarcation, this paper discusses the feasibility of using UAV aerial survey technology and real 3D display and other modern surveying and mapping technology, which has certain reference significance for the similar projects.

Research on the establishment of digital height datum in Golmud

DOU Chao, AN Xiangdong, ZHAO Lijiang, ZHANG Shengpeng, BI Taiwu

2020, 0(8):  108-111.  doi:10.13474/j.cnki.11-2246.2020.0259

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Geoid (digital height datum) provides a new way for the establishment and maintenance of national height datums. However, limited by the terrain and gravity data, the establishment of digital height datum with a high precision on plateau has always been a difficult problem in the field of geodesy. Taking Golmud as an example, we discuss the establishment method of precise digital height datum in plateau area. Firstly, based on gravity data and topographic data, we determine the gravity geoid in Golmud through the Helmert's second condensation method. In the computation, to improve the accuracy of gravity geoid on plateau, the topographic data with high resolution and high precision is used to recovery the short wave of the geoid. Then, the digital height datum of Golmud is established through aligning the gravity geoid to the National Vertical Datum 1985 by a spherical cap harmonic method. Compared with 67 GNSS/leveling points independently, the accuracy of the determined gravity geoid is 3.0 cm, the corresponding precision of digital height datum of Golmud is 2.0 cm.

Time series spectral clustering analysis of taxi data

ZHAO Jiayao, LI Hongwei

2020, 0(8):  112-116.  doi:10.13474/j.cnki.11-2246.2020.0260

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Taxis running in urban space generate a lot of OD data. The time-series of data presents periodic characteristics and objectively reflects people's travel behavior patterns. The spectral clustering algorithm is used to explore the travel characteristics and similarities of spatial units in the Fifth Ring Road area of Beijing. Because the temporal-spatial behavior characteristics are affected by the neighborhood and functional zoning, the study adds the neighborhood factor and the functional area factor to improve the time series similarity measurement method, and realizes the space and functional area expansion of the time series spectrum clustering algorithm. Furthermore, it can increase people's understanding of travel behavior characteristics under different time and space conditions, so as to provide different services for different spatial units, such as the frequency of bus in different time periods, the dynamic adjustment of the business hours of malls, the real-time transformation of taxi waiting points in different time and space environments, and the regulation and optimization of service guarantees in different regions, etc. The research helps to reduce urban energy consumption, makes more rational use of resources, and helps residents to realize smart life.

Making slope map of the third national land survey based on high-precision DEM of 2 m grid cloud data

LI Guohua

2020, 0(8):  117-121.  doi:10.13474/j.cnki.11-2246.2020.0261

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The topography changes with time. The slope map is made with high-precision EDE data, and then the ridge coefficient is calculated, which can more accurately calculate and count the cultivated land area. Based on the DEM data generated from the 2 m grid point cloud data, according to the relevant technical requirements of the third national land survey and the gradient classification requirements of cultivated land, the gradient classification grid data map is generated. Vectorize the gradient classification grid data map, generate the gradient classification vectorization data. Integrate the map spots, smooth the boundary, reconstruct the topology, and deal with the vectorization data according to the cutting and other processing, the slope map and relevant attribute data of the survey area are made. At the same time, the results of slope map production are analyzed, and the technical differences of slope map produced by different scale grid are obtained, and the application of high-precision slope map is prospected.

Analysis of land use change based on geographical provincial condition monitoring: taking old industrial zone in the east of Jinan as an example

ZHAO Xiangyang, ZHAO Yun

2020, 0(8):  122-125,159.  doi:10.13474/j.cnki.11-2246.2020.0262

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The traditional land use change analysis method can not satisfy the demand of large-scale and long-cycle dynamic land change monitoring, which also can not adapt rapid development demand of the city. Based on the monitoring data of Shandong geographical provincial condition, this paper studies the land use change of the old industrial area in the east of Jinan by using various land use index models. These index models include dynamic degree, transition matrix, frequency degree, importance degree, etc. Through the quantitative analysis of the evolution of the spatial pattern of various land types in the old industrial zone from 2017 to 2019, this paper reveals the evolution mechanism of the spatial pattern of land use, combined with the relevant data of social and economic development, this paper also makes a reasonable explanation on the causes and internal driving force of the change, which provides practical data support and decision-making basis for the formulation of new urbanization policies.

Constructing and assessment of the resource environment pressure index system of ingoing ground: a case study of Nayong county of Guizhou

ZHENG Junning, XU Hong

2020, 0(8):  126-130.  doi:10.13474/j.cnki.11-2246.2020.0263

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Taking Nayong county of Guizhou province as the research object of ingoing ground for improving living condition this paper, constructs evaluation index system, and evaluates resource environment pressure of the ingoing ground. The analytic hierarchy process (AHP) is used to determine index weight at the same time. Resources and environment pressure is calculated, and the results are divided into relatively high, medium and low pressure area. The analysis result shows that the overall resource of Nanyong county is poor, and the ecological environment is relatively weak, the per capita resource is low, which lead to the overall pressure of the resource environment very lange. By analyzing of the incidence of poverty and the evaluation of resources and environment, which find out that the correlation between resource environmental stress and poverty incidence is negative.

Research and implementation of key technologies of natural resources big data fast service platform

GUO Shuangren, TANG Zhiqing, TANG Xianlong

2020, 0(8):  131-134,138.  doi:10.13474/j.cnki.11-2246.2020.0264

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At present,it is difficult to realize the rapid service of massive spatial data (including fast access, display, retrieval, distribution and online service) in the industry, which restricts the sharing of natural resource data. To solve the above problems, this paper proposes a solution of "optimizing the access, retrieval and display efficiency of massive spatial data based on distributed column-based database and Hilbert spatial coding rules". The specific technical route is described in detail, and the development and promotion of big data rapid service platform is further explained. The purpose of this paper is to make contributions to meet the urgent demand of economic and social development for rapid service of massive spatial information in the new era.

Geographic entity spatial orginzation, variety characters and its application

ZHANG Yiran, JIA Guangjun, TAO Yingchun, ZHU Xiaokun, ZUO Xiaogang, CUI Lixin

2020, 0(8):  135-138.  doi:10.13474/j.cnki.11-2246.2020.0265

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This paper describes the construction content of geographic entity, introduces the organization and expression form of geographic entity based on image unit distinguish, and compares the difference between traditional topographic map and entity data organization form. This paper analyzes the spatial and temporal variety characteristics of geographical entities, and expounds the characteristics of spatial consistency expression to geographical entities on ground objects. Based on the multi-source vector data, the method and steps of geographic entity fusion are designed, and the concrete application of the fusion results is introduced with the building entity as an example. This paper provides the reference for the study of geographic entities in GIS.

Wheel detection integrating convolutional neural network and recurrent neural network

MA Chao

2020, 0(8):  139-143.  doi:10.13474/j.cnki.11-2246.2020.0266

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Target detection is a key technology of target location based on vision. Aiming at the environmental sensitivity of the existing wheel detection methods,this paper proposes a wheel detection model integrating RNN and Faster R-CNN named FusionRNN. Leveraging RNN to deal with temporal information and CNN to extract the recessive characteristics in the spatial domain, it can improve the real-time performance, reduce the number of parameters, and make the model more expressive.At the same time, it has the ability to analyze the semantic relationship between serialization vectors and recognize the geometric features of wheels. The model can accurately detect the wheel in the three-dimensional point cloud scanned by the LiDAR, provide the vehicle position information for the intelligent manipulator used to grab the vehicle to the designated parking space, accurately obtain the vehicle's center of gravity, and realize the safety, rapid capture and storage of the vehicle.

Construction on spatiotemporal integration and operation of ancient and modern maps platform in China

PAN Qian, BU Qinghua, WANG Dan

2020, 0(8):  144-147.  doi:10.13474/j.cnki.11-2246.2020.0267

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As an important source of historical geographic information, the demand for ancient maps is increasing. In view of the lack of a systematic and comprehensive display platform for ancient and modern maps in China, based on the registration of 4000 pieces of ancient and old maps of China, a spatiotemporal integration and operation platform of ancient and modern maps in China is built by using geographic information system, database, SOA, Web services, ArcGIS API for JavaScript and other technologies. Through the overlay and comparison of ancient and modern maps, the platform can directly show the changes of geographical and human environment on PC and mobile. The platform provides the functions of fast query, retrieval, display, input and output, and management of ancient map image data to provide support for urban planning and construction, historical geography research.

Exploration of the innovative ability cultivation mode of GIS students driven by “geographical literacy and surveying and mapping skills”

CAI Zhongliang, WENG Min, SU Shiliang, KANG Mengjun, FEI Teng, TIAN Jing, REN Fu

2020, 0(8):  148-152.  doi:10.13474/j.cnki.11-2246.2020.0268

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In the era of rapid development of information technology and mass innovation and mass entrepreneurship, innovation and innovative talents have become an important driving force for national development, and innovation education and cultivation of innovative talents have become an important task for colleges and universities. In this paper, taking the GIS major of Wuhan University as an example. Combined with the characteristics and advantages of the major, the cultivation mode of the innovation ability of GIS major students driven by "Geographical literacy, Surveying and mapping skills" and the cultivation approaches of "solid foundation, emphasizing knowledge, strengthening skills" are explored. Focusing on the internal and external factors of the cultivation and growth of innovative talents, innovative development exploration has been carried out from four aspects, Optimizing talent training program and curriculum system, innovative teacher team and new teaching methods, innovation platform and conditions of teaching and scientific research, evaluation and incentive mechanism of innovative talents development. Through the practice, remarkable innovation achievements have been achieved and good demonstration has been produced.

Application of mobile 3D laser scanning technology in tunnel structure monitoring

ZHANG Li, CONG Xiaoming, ZHAO Shengliang

2020, 0(8):  153-156.  doi:10.13474/j.cnki.11-2246.2020.0269

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The monitoring of subway tunnels in China mainly uses the traditional measurement based on the total station. The monitoring points are limited and the monitoring process is slow. It is difficult to fully reflect the deformation of the tunnel structure. Aiming at the structural characteristics of subway tunnels, this paper proposes a tunnel structure monitoring scheme based on a new mobile 3D laser measurement technology. Firstly, the mobile laser scanning is used to obtain high-density point cloud data, and then the ring stitching seams at the top of the tunnel are automatically identified and extracted. Based on the point cloud data, the ring segment surface information is extracted and the ring slice structure is analyzed. Finally, The comprehensive data management platform is used to conduct management analysis on various monitoring results to achieve scientific management of tunnel structure changes. The actual engineering application shows that the scheme's monitoring results are accurate, the results analysis and management are more scientific, and it meets the needs of tunnel health monitoring.

Accurate fitting and deformation analysis of metro tunnel section based on point cloud

LI Zhiyuan, WANG Jian, YU Deliang, SUN Wenxiao

2020, 0(8):  157-159.  doi:10.13474/j.cnki.11-2246.2020.0270

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Aiming at the problem that 3D laser scanning technology is difficult to accurately fit and analyze the deformation of tunnel sections with different shapes, such as circular and horseshoe-shaped subways, a method of tunnel section fitting analysis based on cubic b-spline curve is proposed.Firstly, cubic b-spline curve is used to fit the section. Then, the feature points of the cross section are extracted according to the fitted curve to realize the deformation analysis of the cross section. The cross-section analysis of the point cloud data of a subway tunnel shows that this method can analyze deformation information of tunnel section quickly and accurately.

Analysis and application study of tunnel segment stagger based on mobile 3D scanning technology

ZHAO Yabo, WANG Zhi

2020, 0(8):  160-163.  doi:10.13474/j.cnki.11-2246.2020.0271

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The segmentstagger is one of the main diseases of subway tunnel, usually due to the poor construction control of shield machine or the change of tunnel load. Other diseases such as convergence deformation and water seepage can also be caused by the occurrence of segment staggered.The traditional method mainly uses the manual inspection, because of the night window period short influence, this method efficiency is low, the result is difficult to accurately quantify. The three-dimensional laser scanning system based on track is used to detect the tunnel stagger, and the segment is divided and the mileage is matched based on the 3D point cloud information of each ring. Taking Qingdao metro line 2 as an example, this paper introduces the application of mobile scanning technology in the detection of segment staggered, which provides some reference for its popularization and application in other tunnels.