Table of Content

25 April 2020, Volume 0 Issue 4

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Coordinate location of corner reflector in vehicle-mounted SAR image based on scale space

DAI Guomeng, PAN Bin, LUO Tianwen, WEI Siqi

2020, 0(4):  1-5.  doi:10.13474/j.cnki.11-2246.2020.0102

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Determining the high-precision image coordinates of CR in SAR images is the basis of geometric correction, radiometric correction and deformation detection of SAR images. This paper presents a coordinate location method of corner reflector in vehicle-mounted SAR image based on scale space. Through corner reflector location experiment in the simulation data and vehicle-mounted SAR data, the feasibility and stability of the method are verified. Compared with the location result after geometric correction using ground control points, the method satisfies the location accuracy of sub-pixel level and does not need ground control points.

UAV image matching feature point coarse error elimination based on image theory algorithm

XI Wenfei, SHI Zhengtao, LI Guozhu

2020, 0(4):  6-10.  doi:10.13474/j.cnki.11-2246.2020.0103

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In the process of UAV image matching, rough error is inevitable. Therefore, it is very important to obtain feature points with high robustness for UAV image matching. The traditional method is using classical RANSAC algorithm for coarse error elimination, which is affected by the sampling times, error threshold, and remaining partial mismatched points. By using graph theory, the feature points extracted by SIFT algorithm are preprocessed, that is the feature points with lower energy are removed by constructing the energy function of feature points, which can improve the robustness of matching feature points and reduce the feature points coarse error. The paper proposes a new method, which combines the graph theory algorithm with the classical RANSAC algorithm to eliminate the rough error. The method is named GSIFT-RANSAC algorithm, which can improve the robustness of feature points and obtain the homography matrix with high accuracy. Using different data for verification, gross error elimination rate of the algorithm proposed in this paper is 5.31% and 14.29% higher than the algorithm using graph theory to remove feature points alone, which indicates that the effect of proposed method is better.

A building boundary regularization method by contrasting Harris operator and Susan operator

WANG Jiexi, FENG Dejun, CHEN Jianfei

2020, 0(4):  11-15.  doi:10.13474/j.cnki.11-2246.2020.0104

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The precise extraction of the top boundary of a building plays a very important role in establishing a digital city and so on. In order to solve the problem of irregular boundary of buildings extracted from remote sensing images, combined with Harris operator and Susan operator, a method for regular fitting of rough extracted building boundaries is proposed. Firstly, pre-process the rough-extracted top boundary of the building to eliminate noise effects. Then the Harris algorithm and Susan algorithm are used to detect the corners of the pre-processed building boundary respectively. Finally, the corner points of the extracted boundary corner points are sorted and regular fitting is connected to obtain the regular building boundary. The experimental results show that the boundary of the building treated by this method is smooth and basically consistent with the actual boundary of the building.

Automatic extraction of buildings based on instance segmentation model

HU Minjun, FENG Dejun, LI Qiang

2020, 0(4):  16-20,62.  doi:10.13474/j.cnki.11-2246.2020.0105

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Traditional remote sensing image target extraction methods mostly use visual interpretation or processing of pixel information, which is difficult to apply to complex scenes of high-resolution remote sensing images. However, the existing convolutional neural network semantic segmentation model may cause the extraction of target adhesion due to difficulty in achieving high precision. Aiming at this problem, this paper improves the instance segmentation model Mask R-CNN and proposes an efficient and accurate high-resolution remote sensing image building extraction algorithm. Firstly, convolution operation is added to the original feature extraction part of the Mask R-CNN to reduce the aliasing effect caused by upsampling. Then, a branch is added to the original mask prediction structure to improve the effect of mask prediction. Finally, train the improved network on the building dataset, the results show that the proposed method can accurately predict the top of each building independently, without target adhesion, and the mAP value is improved compared with the Mask R-CNN, which can effectively realize the refined extraction of remote sensing image buildings.

A point cloud registration algorithm based on ISS-SHOT features

LI Yuxiang, GUO Jiming, PAN Shangyi, Lü Lili, LU Zhuxing, ZHANG Di

2020, 0(4):  21-26.  doi:10.13474/j.cnki.11-2246.2020.0106

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Aiming at the problems of error-corresponding points, slow convergence rate and long time for the point cloud registration, a registration algorithm based on theintrinsic shape signatures(ISS) and signature of histograms of orientations(SHOT) is proposed.After down-sampling by voxel grid method, the feature points of point cloud are extracted by the ISS algorithm, described by the SHOT and matched by the cosine similarity. Then, the wrong corresponding points are eliminated by the RANSAC algorithm, so that the two point clouds obtain a good initial positon. Finally, an accurate result can be obtained based on point to plane ICP algorithm.The experimental results show that compared with the traditional ICP algorithm and the ISS-based SAC-IA+ICP algorithm, the proposed algorithm has higher registration accuracy and efficiency, and it is robust to point clouds with large data quantity and low overlap rate.

Automatic extraction of road traffic marking from vehicle-borne close-range stereo images based on geometric rules

YUAN Jiaming, ZHANG Ka, CHEN Hui, SU Dong, WANG Pengbo

2020, 0(4):  27-33.  doi:10.13474/j.cnki.11-2246.2020.0107

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Road traffic marking is an indispensable data in road navigation maps, which plays an important role in making high-precision maps, and navigation maps with higher accuracy, richer and clearer road detail information. The automatic extraction of road traffic marking information in vehicle-borne close-range stereo images is taken as the research target in this paper. For rapid and accurate collection of road traffic marking, an automatic extraction method is proposed based on geometric features. Firstly, the geometric features of road traffic marking are analyzed. Secondly, the extraction rules of traffic marking are constructed based on geometric features. Finally, combined with the foregoing rules, the automatic collection of three-dimensional spatial information of traffic marking is realized based on the seed points. The close-range stereo images collected by mobile measurement system of Nanjing normal university have been carried out to verify the experiment. The experimental results prove that this method compared with the traditional human-computer interaction collection method, has mere advantages in collection efficiency of traffic marking feature points and the geometric similarity of marking. This method approved it provides a technical support for the production of high precision navigation map for reference.

Classification study of Mikania micrantha kunth from UAV hyperspectral image band selection

LIU Yanjun, ZHANG Gui, WANG Xiao, ZHOU Cui, YANG Zhigao, WU Xin, ZHANG Juan

2020, 0(4):  34-39,52.  doi:10.13474/j.cnki.11-2246.2020.0108

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Mikania micrantha kunth is one of the most harmful invasive species, which has caused serious damage to our country’s forest ecosystem for its’ rapidly growing and spread.The relevant management needs an effective method for monitoring Mikania micrantha kunth.The traditional methods of manual investigation requires a lot of manpower and material resources,which are considerably costly and inefficient.In recent years,the rapid development of hyperspectral remotes sensing technology provids a new method of monitoring the Mikania micrantha kunth.This paper bases on the remote sensing image data of Zengcheng forest farm in Guangdong Province,which is obtained by the Nano-Hyperspec hyperspectral imaging instrument carried by UAV. The hyperspectral data is pretreatmented by geometric correction,image denoising,radiometric calibration and bad band elimination. OIF, ABS, ASP+ABS methods for band selection are used, obtaining the characteristic wave band of the most informative and low correlation band to constitute the optimal band combination for Mikania micrantha kunth. Generating three remote sensing images, and using the support vector machine method (SVM) classify the three different remote sensing images.The degree of response of the three band combinations to the hyperspectral characteristics of Mikania micrantha kunth is evaluated with the accuracy of the classification results, and a band combination better reflected the spectral characteristics of Mikania micrantha kunth is selected. The experimental results show the cartographic accuracy and user accuracy are 74.62% and 66.52% by using the method of OIF, 74.37% and 67.43% by using the method of ABS, 95.98% and 92.98% by using the method of ASP+ABS,which has the best classification accuracy. Compared with the method of OIF, the method of ASP+ABS improvs by 21.35% and 26.46%.Compared with the method of ABS, the ASP+ABS improves by 17.15% and 19.3%.Compared with the other two methods, the band selection methods of ASP+ABS in this paper has the better performance of reflecting spectral characteristics of Mikania micrantha kunth, which can provide an effective technical method of monitoring the Mikania micrantha kunth.

Scale effect of airborne LiDAR DEM in watershed hydrological analysis and simulation

LAN Jinjing, YU Haiyang, CHEN Lin, MA Huihui, ZHANG Huiyong

2020, 0(4):  40-46.  doi:10.13474/j.cnki.11-2246.2020.0109

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DEM data is the basis for watershed hydrological analysis and simulation. The results of hydrological analysis and simulation have been impacted profoundly by different resolution scale of DEM. Based on the DEM data acquired by airborne LiDAR, the discrepancies resulted from different resolution DEM in slope extraction and hydrological index analysis are analyzed. And the SWAT distributed hydrological model is used to simulate and analyze the hydrological effects of DEM data with different resolutions. The research shows that, with the decrease of the DEM resolution, the slope and the mean SPI reduced, the mean TWI increased. The mean LSF increases first and then decreases, the maximum LSF is at 10 m resolution. The SWAT model simulation results indicate that, with the lower resolution and the smaller value of the slope, TWI becomes larger, evapotranspiration increases, surface runoff depth reduces while the amount of soil leakage and underground runoff is first decrease and then increase, same as LSF, 10 m is the extreme point.

Fusion application of ground and vehicle laser point cloud in underground garage mapping

LIU Fengzhu, YANG Ying, YANG Bogang, ZHANG Panke

2020, 0(4):  47-52.  doi:10.13474/j.cnki.11-2246.2020.0110

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Underground space utilization has attracted more and more people’s attention. Underground space measurement is affected by many factors, such as the lack of GPS signals in the underground space, more obstructions, and low efficiency of traditional methods. To solve this problem, this paper proposes a data acquisition scheme combining on-board laser scanning system and ground 3D laser scanning. This scheme can effectively utilize the advantages of ground 3D laser scanning and vehicle mobile laser scanning, and adopt a multi-source point cloud data. Fusion technology to efficiently acquire complete point cloud data in underground space. Finally, through the underground garage data collection experiment, the effectiveness and reliability of the scheme are verified, and provide technical support for the future extensive development of underground space mapping.

Algorithm of pylon automatically localization and point cloud extraction in power line inspection based on LiDAR

HUANG Lujun, CHEN Guangping, YUAN Shuai, TU Pu, QIAO Jie

2020, 0(4):  53-57,75.  doi:10.13474/j.cnki.11-2246.2020.0111

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An automatic pylon localization and point cloud extraction algorithm is presented in this paper in order to solve the problem of pylon automatically extraction from point cloud of power line inspection. Firstly, 2D mesh is applied to get bias and variance of height of point cloud in each grid, and in which pylon is located cursorily. Secondly, points from tower are extracted roughly according to continuity of height in grids. Afterwards, points from tower are accurately extracted based on the structural features of pylon and power line, in which the density in different hierarchy of height and open operation of image are applied. Finally, point cloud collected from light small UAV-LiDAR is applied in experiments for experimental verification. Experiments show that the presented algorithm works well in the problem of tower extraction, and also has a high performance under condition of poor quality of point cloud. Algorithm presented in this paper has some value in application of power line inspection with LiDAR.

BeiDou triple-frequency cycle-slip detection and repair based on geometry-free and ionosphere-free combination

CUI Lilu, HE Qiong, ZOU Zhengbo, XU Wenchao, JIANG Xueli, WEI Pengzhi

2020, 0(4):  58-62.  doi:10.13474/j.cnki.11-2246.2020.0112

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View to the problem that the detection and repair accuracy of cycle slip under the strong ionospheric delay affects, the geometry-free and ionosphere-free combination has been constructed based on the characteristics of BeiDou triple-frequency data in this paper and the combination coefficients have been selected. Then, combined with MW combination and ionospheric residual method, the cycle slip test quantity is constructed to realize the cycle slip detection and repair of BDS measured data. In the process of experiment, this algorithm has been tested fully and effectively by setting different types of cycle slip. The experimental results show that this algorithm can detect all cycle slip, including insensitive ones,and repair them completely.

Carrier/Doppler smooth pseudorange in Android mobile phone

ZHANG Shuwei, GAO Jingxiang, ZHAO Long, LI Zengke

2020, 0(4):  63-67.  doi:10.13474/j.cnki.11-2246.2020.0113

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To improve the accuracy of GNSS positioning in Android mobile phone, the pseudorange observation is smoothed by carrier phase and Doppler. Firstly, the acquisition method of GNSS raw measurement at Android mobile phone is given. Then the carrier phase smoothing pseudorange and Doppler smoothing pseudorange algorithm models are derived. An reasonable and effective experiment is designed to evaluate the accuracy of the algorithms. The result shows that in the static test both carrier phase and Doppler smoothing algorithm can improve the positioning accuracy of the original pseudorange, and the Doppler smoothing algorithm performs better. In the dynamic test, the Doppler smoothing algorithm can obtain better positioning accuracy than the original pseudorange, but the carrier phase smoothing algorithm is worse than the original pseudorange. Due to the restriction of hardware, the rate of cycle slip and signal losing lock accounting for more than 50%. The availability of carrier phase in the mobile phone is low. The optimal smoothing time constant of Doppler smoothing algorithm is less than or equal to 10 seconds, which has great potential for real-time dynamic positioning.

Influence of anchors on the precision of autonomous navigation for BDS

GONG Xiaoying, CAI Shixiang

2020, 0(4):  68-75.  doi:10.13474/j.cnki.11-2246.2020.0114

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This paper has introduced the orbit determination and time synchronization observation equations. Aiming at the simulated constellation of BDS, AutoNav for 60 days has been implemented adopting the simulated inter-satellite and satellite-anchor observations. The influence of the number of anchors and the continuity of anchor observations on the precision of AutoNav has been discussed, considering the three different types of satellites for BDS. Results indicate that the number of anchors and the continuity of anchor observations have no affect on the result of RERR and CERR, but the precision of URE can be improved distinctly by adding one anchor into the constellation, and which can be further improved when increasing the number of anchors with a limited effect. On the other hand, for the continuity of anchor observations, the longer the interruption time of anchor observations, the lower the precision of AutoNav. Therefore, the high observation frequency to satellites from anchors should be ensured to keep the high precision of AutoNav. Besides, the influences of the number of anchors and the continuity of anchor observations on the three types of satellites have no difference.

Discussion on detection method of the measurement accuracy about inertial navigation track detector

LIU Ruhong, LIU Chenglong, HE Jinxue, YANG Xuefeng

2020, 0(4):  76-80.  doi:10.13474/j.cnki.11-2246.2020.0115

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According to the unclear part of the current standard of the calibration of the track detector, we propose a more reasonable method for detecting the actual measurement accuracy of the track detector and is introduced the method of measuring the basic data of the track in test site. Finally, taking the actual detection of an inertial navigation track detector as an example, the difference between this method and the normal method is analyzed, and the correctness of the method is verified. The actual measurement accuracy of the detected track detector is also statistically analyzed. It provides a reference for the detection method and engineering application of the inertial navigation track detector.

Spatial and temporal distribution characteristics and influencing mechanisms of air quality index in urban areas

WU Yiling, LI Chengming, DAI Zhaoxin, WU Zheng

2020, 0(4):  81-86.  doi:10.13474/j.cnki.11-2246.2020.0116

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Jinan is one of the cities with the most severe fog and haze in China. It is of great significance to explore the spatial and temporal distribution of air pollution and its impact mechanism in this area. Geostatistical interpolation is used to analyze the spatial and temporal distribution characteristics of AQI in the main urban area of Jinan, and the risk factors and influencing mechanism of AQI are quantitatively analyzed by using geographic detector. The results show that, on the interannual scale, the AQI in the main urban area of Jinan city decreases year by year in time, and generally presents the distribution trend of low southeast and high northwest in space. On the seasonal scale, the AQI in the main urban area of Jinan has distinct seasonal differences in time. The order from high to low is winter, spring, autumn and summer. Spatially, the AQI in the main urban area of Jinan presents a distribution pattern of high in spring and winter, low in southeast and north, low in summer, low in south and high in north in autumn. On the monthly scale, AQI in the main urban area of Jinan city presents typical “U” distribution characteristics, with the highest value in January and December and the lowest value in August. The influence of each factor interaction is far greater than that of single factor. Among them, the interaction of land use type annual average precipitation has the greatest influence on AQI in the main urban area of Jinan. The study shows that AQI in the main urban area of Jinan is most affected by land use types and annual average precipitation.

Volunteered nighttime light remote sensing based on civil aviation aircraft platform

SU Ruibo, WANG Chisheng, WANG Yongquan, TANG Qiandi

2020, 0(4):  87-90,95.  doi:10.13474/j.cnki.11-2246.2020.0117

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As an active branch of remote sensing, nighttime light remote sensing can reflect the traces of human social activities. It has unique advantages in monitoring the city, assessing economic parameters and estimating the impact of major events. With the increasing maturity of data mining of night-light remote sensing, higher requirements are required for the traditional night-light remote sensing satellite. Based on concept of volunteered geographic information, this paper introduces a new method which is called PARS(passenger aircraft remote sensing). We capture night-light remote sensing image of Changsha using this method, and then compare the results with the traditional satellite remote sensing data. The data show that night-light remote sensing data captured by PARS has higher resolution, more bands and rapider revisit period than traditional remote sensing. To conclude, it is a low-cost, flexible and diversified remote sensing data acquisition method with great potential.

SBAS surface deformation monitoring with PS feature points

NIE Yunju, XIONG Jiacheng, CHENG Penggen, LUO Yue

2020, 0(4):  91-95.  doi:10.13474/j.cnki.11-2246.2020.0118

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In view of the problem that the artificial selection of ground control points in SARscape SBAS will affect the monitoring results, a SBAS surface deformation monitoring method with PS feature points is proposed. By setting the amplitude dispersion index and the coherence threshold in PS, the feature points in PS monitoring results are extracted as the ground control points for orbit refining and deformation inversion. The Sentinel-1 images covering Nanchang area from March 2017 to December 2018 are used to monitor and verify the surface deformation. Both the monitoring results of this method and PS method show that the study area has a small increase during the monitoring period. The correlation of annual average sedimentation rate reached 0.959, which is highly consistent. The monitoring results of this method, PS method and the SBAS method of manually selecting ground control point are compared with the leveling data. The error between this method and the leveling data was no more than 3.5 mm, which shows the validity of this method.

The technology of image tile change detection based on Siamese convolutional neural network

WAN Ranran, CHEN Juan, LIAO Mingwei, LIU Yi, PANG Chao

2020, 0(4):  96-100,129.  doi:10.13474/j.cnki.11-2246.2020.0119

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In view of the fast change of geographic information and the inefficiency of traditional updating methods, many scholars have proposed various kinds of change detection methods, but most of these methods experiments are based on image data, which require higher image preprocessing requirements, and the detection accuracy is always unstability, which is greatly affected by the quality of data sources. While in Tianditu maps, Baidu maps, Google maps and other electronic maps, several levels of image tiles can be downloaded free of charge. Therefore, this paper proposes to use Tianditu map image tiles for experiment, use Siamese convolution neural network (SCNN) and deep learning technology, develop a high-precision change monitoring algorithm based on SCNN, quickly find the change area, and realize the change information detection of geographic information.

Automatic classification of pole-like objects in road scene by back propagation neural network

LI Pengpeng, LI Yongqiang, ZHAO Shangbin, FAN Huilong

2020, 0(4):  101-105,120.  doi:10.13474/j.cnki.11-2246.2020.0120

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Aiming at the problems of low accuracy and low automation of pole-like objects classification in vehicle laser scanning data, a classification method based on BP neural network is proposed. Firstly, according to the point cloud characteristics of the pole-like object, ten eigenvalues are selected to obtain the feature vectors of the pole-like object clustering unit, and then eigenmatrix is constructed. Secondly, the BP neural network model is trained by using the sample set and the classification model is saved. Finally, the BP neural network classification model is used to classify the pole-like object in the test area. The experiment showed that the classification accuracy of the method for pole-like objects could reach 95.34%, which also verifies the effectiveness of the method.

Grid analysis of land use based on natural breaks (jenks) classification

LI Naiqiang, XU Guiyang

2020, 0(4):  106-110,156.  doi:10.13474/j.cnki.11-2246.2020.0121

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Land use plays an important role in the unified management of natural resources. In the face of data from different regions and years, it is particularly important to analyze and compare the caliber uniformly, and at the same time to reflect the differences between them. In this paper, the data of land use status of Yixing city in 2009 and 2017 are used as data sources. Using land classification criteria to extract three types of land use, and attempts to analysis through cell division of different sizes, find the suitable size for this data. Then the classification range is demarcated based on the natural breaks (jenks) Classification method, to comprehensive analysis on the distribution and change trend of three types of land use in Yixing city, it truly reflects the land use situation of Yixing city. By selecting appropriate spatial scale and classification range delimitation method, this paper constructs an operational and scientific land use data grid method, which provides basis for the overall management and comprehensive management of natural resources departments.

Application of optimal weight combination method in predicting coal mining subsidence deformation

LU Xiaohong

2020, 0(4):  111-115.  doi:10.13474/j.cnki.11-2246.2020.0122

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The prediction of ground subsidence and deformation in coal mines mainly based on the theory of subsidence prediction of coal mining. Deformation prediction models based on deformation analysis theory currently focus on single model prediction. Based on the combination forecasting idea, a non-equidistant gray prediction model and a BP neural network model are used as prediction single models. The measured surface settlement value above the coal mining face of a coal mine in northern Shaanxi is used as the data source. The optimal weight combination is used to optimize the prediction results of the single model, and the weights of the two single models in the combined model are 0.466 7 and 0.533 3. The prediction results of some monitoring points are selected to evaluate the model accuracy, and the results show that the accuracy of all three prediction models reached one level. By comparing the prediction results of the three models, the accuracy of the optimal weight combination prediction model is significantly improved compared with the single model, and the prediction results have significant gains compared with the non-equidistant grey prediction model and the BP neural network prediction model.

Quality evaluation of generalization of linear features in land use map

WANG Xiaoyan

2020, 0(4):  116-120.  doi:10.13474/j.cnki.11-2246.2020.0123

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As an important component of land use map generalization, the comprehensive quality of linear features has great significance to improve the accuracy of automatic cartographic generalization. So based on the theory of fuzzy comprehensive evaluation, quality evaluation of comprehensive linear features in land use map will be studied in this paper. First of all, evaluation indicators,which include geometric factors, topological factors, structural factors and gestalt factors are chose using method of cartographic generalization constraints. Secondly, evaluation rank and weight set are confirmed, and then a quality evaluation model of comprehensive linear features will be built. At last, the validity of the evaluation method will be verified by experiment. It is concluded that the quality evaluation model in this paper can be provided a new thought for evaluating generalization quality of linear features in land use map.

A slope-based weighting method for fusing SRTM and ASTER

ZHENG Tingting, CHEN Chuanfa, LIU Hongtao

2020, 0(4):  121-124.  doi:10.13474/j.cnki.11-2246.2020.0124

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To produce a high-accuracy public available DEM,a weighted mean method based on terrain slope for fusing SRTM and ASTER is developed in this paper. Specifically, the two public DEMs are first georeferenced. Then, the fusion weights of the two DEMs are calculated with respect to their elevation errors under different slope grades. Finally, the two DEMs are fused based on the fusion weights. The fused DEM is assessed using some high-precision control points. The results indicate that the precision of the fused DEM is improved, whose elevation standard deviation error is 5.65 m and 1.20 m lower than those of SRTM and ASTER, respectively.

Evaluation of urban spatial attraction range in Anhui province based on weighted Voronoi diagram

ZHAO Jiaxing, Lü Weicai, GE Xiang, CHEN Weiwei

2020, 0(4):  125-129.  doi:10.13474/j.cnki.11-2246.2020.0125

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In order to evaluate the influence range of prefecture-level cities in Anhui province, this study uses the spatial dissection characteristics of Voronoi diagrams and the combination of subjective and objective comprehensive weighting methods, and proposes the use of combined weights to calculate the central intensity, which is used as a weight to introduce models to establish Anhui province. The city-weighted Voronoi diagram is analyzed in association with the perimeter-area fractal theory and the ranking of new first-tier cities published by the New First-Line City Institute to analyze the spatial impact of prefecture-level cities in Anhui province. After analysis and verification, the established combination of Voronoi diagram can effectively evaluate the influence range of prefecture-level cities in Anhui province. In addition, it also provides reference for the classification of city grades.

Research on natural resources based on the third national land survey

ZHANG Liren, FENG Ran, QI Zhonghua, LI Deyuan

2020, 0(4):  130-133,138.  doi:10.13474/j.cnki.11-2246.2020.0126

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Natural resources survey system is an important measure to implement the new development concept and promote the reform of natural resource management system, also is the premise and basis for fulfilling the “two unifications and six duties” of natural resource management. The third national land survey (Hereinafter referred to as “San Diao”) data details the status of land development and utilization, changes in natural resource, so it can provide an excellent data foundation for the natural resource survey. Therefore, we combine “San Diao” data and professional data provided byoriginal various natural resource management departments to analyze and explore the natural resource surveyssuch as classification and coding of natural resource elements,extraction of natural resource elements, and we take a test in Ningan in Heilongjiang province as an example, aiming to provide reference for the natural resource survey,which can be replicated and promoted in Heilongjiang province and even the whole country.

Scale feature of moving trajectory

LIU Minshi, LONG Yi, SUN Yong

2020, 0(4):  134-138.  doi:10.13474/j.cnki.11-2246.2020.0127

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Moving trajectory is a trace of a moving object that moves in geospatial environment for a certain purpose. Featured by spatial scale, time scale and semantic scale, moving trajectory data is a special kind of geographic spatiotemporal data. Firstly, the spatial scale feature and time scale feature of moving trajectory data are analyzed in this paper, and the transformation relationship between spatial scale and time scale is established. Secondly, the semantic connotation and semantic scale feature of the trajectory are studied. Four trajectory semantic categories such as moving object, geospatial environment, moving mode and collecting equipment are proposed, and semantic multi-scale characteristics of the trajectory are analyzed from the perspective of geographical environment. Finally, the consistency relationship between the semantic scale and the space-time scale is discussed.

Analysis of spatial and temporal change of land use and urbanization development

TAN Yuanmo, XIE Simei, XIE Rongan

2020, 0(4):  139-142,146.  doi:10.13474/j.cnki.11-2246.2020.0128

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The development of urbanization and using land scientifically and rationally have become the most concerned issues in social development. The change of land use structure and unreasonable land use planning will lead to a series of ecological environment problems. Therefore, it is necessary to monitor the spatial-temporal change of land use and provide effective data support for land use planning and urban development planning. In this article, through the annual range of land use change data, the situation of land use change is analyzed by using the transfer matrix, dynamic attitude, center of land use and land use structure information entropy. Experiments showed that it can reflect truly and comprehensively the status of land use change, fully reflect the relationship between urban development and land use. It is useful for improving the accuracy and reliability of the analysis.

Research on the representation method of the relationship between boundary lines and longitude and latitude lines on the maps

BAI Jinghui, HAN Quanwei, CHEN Huixian, ZHOU Xinwei

2020, 0(4):  143-146.  doi:10.13474/j.cnki.11-2246.2020.0129

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National borders are important parts of the maps. Latitude and longitude lines are used not only to determine location and direction, but also to divide national boundaries between countries. The national borders drawn on the map must not only comply with the laws and legislations, treaties and standards, but also properly handle the relationship between the national borders and the longitude and latitude lines. By introducing the basis for drawing the national boundary lines in the map, the key areas where the relationship between the national boundary line and the longitude and latitude lines are prone to error can be used as a reference for map drawing and map clearance.

Training of spatial information talents in the age of intelligence: challenges and solutions

ZHOU Li, LU Xia, Lü Haibin, LI Yu, PENG Hongchun

2020, 0(4):  147-151.  doi:10.13474/j.cnki.11-2246.2020.0130

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This paper takes the application post demand of emerging industries of intelligent geographic information service as the goal orientation, analyzes the cognitive characteristics and demand of spatial information in the intelligent era, reveals the important position of understanding and cognition of geospatial information in the intelligent geospatial information service, and the future geospatial information talents are facing opportunities and challenges. This paper puts forward a new model of “achievement oriented innovation application ability oriented education” to meet the demand of intelligent geographic information service, and constructs OCCE training approaches/ task groups driven by intelligent geographic information service projects. It actively explores the direction of teaching reform of geographic information engineering in the new era.

Practice course reform and design oriented by ability cultivation

LIU Yawen, WANG Yue, DUAN Yansong

2020, 0(4):  152-156.  doi:10.13474/j.cnki.11-2246.2020.0131

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Practical course in college is an important link to cultivate students’ innovative and entrepreneurial practical ability. This paper puts forward the idea of practical curriculum design based on ability cultivation. The idea aims to cultivate innovative talents of engineering technology for the era of rapid change in new technology, new industry and new mode. It adjusts the verifiable design mode to “goal setting, program planning and implementation”. The students’ main position in practice is emphasized,the rules of practical ability training is followed, and students are guided to pay more importance on participation, reflection, implementation and process. At the same time, the latest development and changes of the industry will be reflected in the practical teaching curriculum. For example, new sensor and data processing platform of cloud-human-computerhybrid collaboration are added to ensure that the knowledge and technology acquired by students are in line with the rapidly developing industry level.Photogrammetry practice course is used as an example to test the idea presented in this paper. The practice has proved that the implementation of the curriculum has achieved good results in training students’ ability of comprehensive analysis, design and creative solution to professional problems.

Low-cost high-precision GNSS static measurement system based on RTKLIB

DONG Jingli

2020, 0(4):  157-160.  doi:10.13474/j.cnki.11-2246.2020.0132

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With the development of science and technology, measuring tools and measuring methods have also changed, the measurement type GNSS showed a trend of price to reduce and the shrinkage of the whole. On the market at present commercial prices ranging from tens to hundreds of thousands of GNSS measuring system, and ground base station and mobile station due to large size, unconvenient to carry, making commercial GNSS measurement system using the crowd is limited to some measurement professionals, in the mass market popularity in many fields. Because of the increase in demand for high precision positioning, such as unmanned aerial vehicle (uav), machine guidance, precision agriculture today, prompted GNSS to low-cost and high-precision measurement system miniaturization Light-duty development. In this paper, the U-type BLOX NEO-M8P low-cost OEM GNSS receiver, the static under 50 km baseline observation, based on RTKLIB accuracy of test results and analysis showed that low-cost GNSS measurement system can achieve cm-level positioning accuracy, meet the needs of measurement and GIS application tests. It showed that using the low-cost measurement system can reduce the economic cost of measurement tasks, which is a measuring levels of GNSS receiver economical choice.

Application of Trimble R9s and automatic displacement monitoring system in Dahongshan mining area

YU Yanbo, YANG Litao, ZHAO Penghui, YANG Shuanglong

2020, 0(4):  161-164.  doi:10.13474/j.cnki.11-2246.2020.0133

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BeiDou/GNSS displacement monitoring technique has the advantages of real-time and highly electronic information compared with traditional total station monitoring. This paper introduces the application of BeiDou/GNSS based on automatic displacement monitoring system in Dahongshan mining area. Trimble R9s GNSS receiver is selected as the main monitoring sensor. A set of hardware and software mixed automatic monitoring system is developed according to the characteristics of mining area key structures. The application in actual mining area shows that the developed system is with high monitoring accuracy and comprehensive functions. The system effectively improved the production safety mechanism in Dahongshan mining Area.