Table of Content

25 February 2021, Volume 0 Issue 2

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Research on coupling and coordinated of urbanization and ecological environment based multi-source data fusion

RUZI Tuersunayi, KASIMU Alimujiang, GAO Pengwen, ZHAO Hemiao, ABULAITI Halimulati

2021, 0(2):  1-6,12.  doi:10.13474/j.cnki.11-2246.2021.0033

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Using DMSP/OLS, NPP/VIIRS and Landsat remote sensing image data, the average nighttime light index (ANLI) and ecological environment index (RSEI) are extracted respectively, and the coupling coordination degree model of urbanization and ecological environment is constructed to quantitatively analyze the coupling coordination development of urbanization and ecological environment in the study area from 2000 to 2015. The results show one belt, one road is the city's urbanization. The results show that:① The urbanization level of Urumqi city has been rising continuously for 2000-2015 years, and the implementation of the "one belt" and "ecological civilization" construction has promoted the urbanization development of Urumqi. ② From 2000 to 2015, the average ecological index increased by 0.119 8, with a growth rate of 30.14%. With the increase of the government's efforts to control the ecological environment, the ecological environment in the study area has gradually improved. ③ From 2000 to 2015, the coupling coordination degree of urbanization and ecological environment in Urumqi ranged from 0.568 3 to 0.627 3, and the coupling coordination degree maintained an increasing trend.

Monitoring of ecological environment changes in the Yangtze River Economic Belt (Jiangsu province) from 1999 to 2020 and analysis of the driving forces of human activities

SONG Ke, WANG Yujun, LI Yin

2021, 0(2):  7-12.  doi:10.13474/j.cnki.11-2246.2021.0034

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Coordinating the relationship between regional urbanization and ecological environment protection is one of the core issues to promote the sustainable development of Yangtze River Economic Belt in our country. According to the existing research, the response relationship between ecological environment changes and human activities drives lacks of supporting data corresponding to time and space, whose impact process is also unknown. This research takes full advantage of the multi-source satellite remote sensing technology in processing and extracting time and space information, takes the districts along the Yangtze river economic belt in Jiangsu section as an example, utilizes the Landsat series of remote sensing images from 1999 to 2000, 2009 to 2010, and 2019 to 2020, and applies the RSEI model to quantitatively analyze the spatial and temporal variation of the regional ecological environment in the research area from 1999 to 2020. Besides, in order to quantitatively explore the impact of human activities (urbanization) on the ecological environment under disparate intensities in different area, the time and space information indicators including the artificial impervious surface (IS) and the nighttime light (NTL) are imported, and the proportion of IS area and the mean value of IS area NTL radiance in each district are defined. Research results indicated that:① From 1999 to 2020, the ecological environment quality of the urbanization areas in the districts along the Yangtze river in Jiangsu Province and their surrounding areas has declined significantly. Moreover, the IS regional areas for different districts in the research region increased rapidly from 2000 to 2009, which led to regional eco-environment quality declined significantly. Simultaneously, the regional eco-environment quality improved slowly from 2010 to 2020 due to increased greening area in partial urbanization region. ② The IS area proportion of each district in the research region has a significantly negative correlation with its RSEI average. However, the negative correlation between the mean value of the NTL radiance in the IS region and the mean value of its RSEI were relatively weakened, especially in the districts where the IS area proportion accounted for more than 0.3. In these districts, the interaction coupling relationship between urbanization and ecological environment became more complex. As a result, their detailed function model needs to be further investigated.

Spatiotemporal changes of key ecological and environmental parameters of Fangcheng Golden Camellia Nature Reserve in Guangxi from 2000 to 2016

LI Guangchao, ZHAO Haimeng, WU Yi, YANG Bin, LI Lihe, ZHANG Hong, YANG Quanguang, CHEN Wei

2021, 0(2):  13-17.  doi:10.13474/j.cnki.11-2246.2021.0035

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Fractional vegetation coverage (FVC) and leaf area index (LAI) are the key parameters of ecological environment, and their remote sensing monitoring of dynamic changes are of great significance to reveal the evolution law of land ecological environment and scientific supervision of ecological environment.Based on the fractional vegetation coverage and leaf area index data of GLASS products from 2000 to 2016, this paper monitored the spatiotemporal dynamic changes of FVC and LAI in Fangcheng Golden Camellia National Nature Reserve in Guangxi.The results show that:the FVC and LAI of the reserve were relatively high from 2000 to 2016, and the changes of FVC and LAI showed an increasing trend the overall spatial distribution of the reserve was that the eastern region was better than the western region. From 2000 to 2016, the annual average FVC and annual average LAI of the protected areas increased by 7.48% and 28.47%, respectively. The lowest value and peak value of the annual average FVC of the reserve were in 2004 and 2016, respectively, and their values were 0.711 and 0.833. The lowest value and peak value of the annual average LAI of the reserve were in 2000 and 2016, respectively, and their values were 3.425 and 4.400.

Study on checking the boundary of ecological protection red line: taking Beijing as an example

ZHANG Yi, YANG Bogang, LIU Yu, YU Yongxin, WU Runze, XU Tianhao, YANG Xudong

2021, 0(2):  18-24.  doi:10.13474/j.cnki.11-2246.2021.0036

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Delineating and strictly observing the ecological protection red line is a national strategic requirement. In order to ensure the precise landing of the ecological protection red line in Beijing, this paper innovatively grades and classifies the red line boundary checking content based on the results of the Beijing ecological protection red line from integrating multi-source data such as geographic national conditions monitoring data, high-resolution remote sensing image data, topographic map data, land use survey data, forestry subclass data, etc. We proposes a method for optimally checking the boundaries of nature reserves, river wetlands, and other units. The comprehensive application in the verification is studied, and the accuracy, current status, integrity, coordination and boundary consistency of the ecological protection red line in Beijing are analyzed and optimized by using the ArcGIS platform to make the red line reach to 1:10 000-scale mapping accuracy, realizing accurate red line landing map. The study provides a base map for the landing, nailed piles, and management of the Beijing ecological protection red line, and provides the data basis for the comprehensive implementation of land and space planning. The research method is also applicable to the ecological protection red line boundary checking studies in other regions of the country.

Threshold segmentation algorithm based on histogram region growing for remote sensing images

LIU Siyan, LI Ling, TE Rigen, LI Zhuqiang, MA Jingyu, ZHU Ruifei

2021, 0(2):  25-29.  doi:10.13474/j.cnki.11-2246.2021.0037

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In the process of traditional thresholding algorithm from single-threshold to multi-threshold, the time complexity will increase greatly, and because of the complexity of remote sensing image information, the segmentation effect will be reduced. This paper creatively proposes the idea based on histogram region growing for remote sensing images. Each gray level is regarded as a threshold, so that the histogram is divided into 256 original small regions by the 256 thresholds. For reducing the number of thresholds, small regions are merged into large regions. Each merging can be regarded as the growth of a region. In each growth, the region with the smallest entropy H is selected as the main one in all regions of the histogram, and then it is merged with the adjacent region by the way of pre-judgment. After growing, the number of thresholds decreases. In the whole process, the growth times are only 255 at most, and the time complexity is stable at O(L). In this paper, single-threshold and multi-threshold experiments show that the algorithm has high accuracy in segmentation results, and has advantages in run time.

Improved SAR image registration algorithm based on SAR-SIFT

LI Pei, JIANG Gang, MA Qianli

2021, 0(2):  30-35,71.  doi:10.13474/j.cnki.11-2246.2021.0038

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During SAR image registration, the performance of the matching algorithm is limited due to the impact of multiplicative speckle. SAR-SIFT uses ROEWA operator instead of difference algorithm to calculate the gradient, which is robust to the speckle of SAR images.In order to further suppress speckle noise, an improved algorithm based on SAR-SIFT is proposed in this paper, which combines nonlinear diffusion filtering and phase congruency. In the proposed algorithm,the nonlinear diffusion filter is used to generate the nonlinear diffusion scale space of the SAR image, and the corresponding SAR-Harris function is calculated on different scale layers in the nonlinear diffusion scale space.To make the nonlinear diffusion scale space robust to speckle noise, the gradient information in the construction process of the nonlinear diffusion scale space is also calculated using the ROEWA operator. In addition, the phase congruency information is used to remove erroneouspoints caused by speckle in the initial key points.Experimental results on multi-source, multi-polarization, and multi-temporal SAR images indicate that our improved algorithm is more robust to speckle noise and improve the match performance compared to the SAR-SIFT algorithm.

An improved algorithm of UAV image mosaic gross error elimination

XI Wenfei, ZHAO Zilong, WANG Shaojun, SHEN Zhijian, LI Shuai

2021, 0(2):  36-39.  doi:10.13474/j.cnki.11-2246.2021.0039

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High-resolution image can be obtained by UAV technology. In order to obtain the high-precision transformation matrix and improve the efficiency of image matching, this paper improves the RANSAC algorithm and adds the gray information of the image to constrain, which further eliminates the coarse error of matching. Finally, it uses the mean square root error to evaluate the quality. In order to verify the reliability of the algorithm, a group of mountain images and a group of building images with rotation angle are selected to verify. The results show that the rejection rate of matching points coarse error is increased by 15.15% and 23.22%, respectively. The mean square root error of the new algorithm is small and the accuracy is significantly improved.

A local iterative phase unwrapping method based on cubature information filter

SUN Yuzheng, XIE Xianming, LIANG Xiaoxing

2021, 0(2):  40-43.  doi:10.13474/j.cnki.11-2246.2021.0040

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To solve the phase unwrapping problem of interferograms with low SNR, a local iterative phase unwrapping method based on cubature information filter is proposed. Firstly, a local phase gradient estimation algorithm based on amended matrix pencil model is used to obtain the phase gradient information in the local window centered at the pixel to be unwrapped. Then the phase unwrapped path is guided by introducing the quality map of the heap sort. And the cubature information filter is used to recursively perform one-dimensional state estimation operation. The state estimate of the pixel to be unwrapped is obtained until all neighbours in the local window of the pixel to be unwrapped are traversed. The phase unwrapping accuracy is improved while maintaining acceptable unwrapping efficiency. The simulation and measured data results prove the effectiveness of the algorithm in this paper.

The accuracy analysis of iterative weighted IEKF-BP combination algorithm for LiDAR/Radar loose combination

SONG Bao, KE Fuyang, ZHAO Xingwang

2021, 0(2):  44-48.  doi:10.13474/j.cnki.11-2246.2021.0041

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In order to verify the superiority of the multi-sensor combined positioning model in high-precision positioning, and to solve the problems of inconsistent prediction accuracy standards, untimely prediction, and high misprediction rates in autonomous positioning and navigation, this article proposes a novel LiDAR/Radar integrated positioning model based on iterative weighted IEKF-BP combination algorithm using its data, and the accuracy of the combined positioning results of the two sensors is analyzed. The experiment shows that the combined result accuracy of the iteratively weighted IEKF-BP combined algorithm is better than the combined positioning accuracy of the single IEKF algorithm and the BP neural network algorithm. Among them, the root mean square errors in the X and Y directions are 0.028 and 0.028 m. The average errors are 0.023 and 0.014 m. The result can accurately reflect the movement state of the carrier and meet the future positioning needs of unmanned driving.

Building extraction based on random forest and superpixel segmentation

CHEN Liyan, LIN Hong, WU Jianhua

2021, 0(2):  49-53.  doi:10.13474/j.cnki.11-2246.2021.0042

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Buildings are an important part of urban space. The extraction of building information is of great significance for basic geospatial database updates, urban planning, urban dynamic monitoring. Building information extraction based on remote sensing images data has a very wide range of applications. This study proposes a method based on random forest and super pixel segmentation algorithm, and automatically extracting buildings from airborne laser point cloud and digital aerial image data. The experiment selects a certain area in Haizhu district, Guangzhou as the research area. The results show that:In a general urban area, more than 90% of buildings can be extracted accurately and quickly, with an average accuracy and completeness of about 90%. The method proposed in this paper has a good application prospect.

Object-oriented construction land change detection from high- resolution remote sensing image

LI Yue, ZHANG Min

2021, 0(2):  54-58.  doi:10.13474/j.cnki.11-2246.2021.0043

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Change detection of construction land is of great significance to the sustainable development of cities. To extract the change information of construction land accurately, this paper proposes a novel construction land change detection method by combining old-time land use vector data, random forest and fuzzy C-means clustering algorithm. According to the prior knowledge provided by the old land use vector data, the construction land is first divided into built-up area construction land and non-built-up area construction land for change detection. Then, object-oriented segmentation is used and various features of the objects, including spectral, GLCM texture, and shape are extracted from high spatial resolution remote sensing images. After applying a local mean assignment and a normalization, multiple feature sets of objects are obtained. Finally, random forest or fuzzy C-means clustering algorithm is employed to achieve the final change detection result in different scene. Our experiments demonstrate that, the proposed method can effectively improve the extraction of change information of construction land in complex scenes with high performance.

Analysis on change detection of high-resolution remote sensing image combining pixel level and object level

LAI Zhengwen, XIA Xiaoyun

2021, 0(2):  59-63.  doi:10.13474/j.cnki.11-2246.2021.0044

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High-resolution remote sensing images have rich texture information, and pixel-level change detection methods mainly analyze the spectral information of the image. Therefore, the use of pixel-level change detection methods for high-resolution remote sensing images has certain limitations. In view of this, a high-resolution remote sensing image change detection method combining pixel level and object level is proposed to solve the problems of salt and pepper and misdetection in the pixel level and object level change detection methods. First, combining the multi-dimensional features of high-resolution remote sensing images, a remote sensing image change detection model is constructed. Secondly, the random forest classifier is used to classify the image, and the pixel-level change detection result is obtained. Finally, the pixel-level change detection result and the image object segmentation result are fused to obtain the image change area and the invariant area. Experimental results show that the algorithm has high accuracy and detection accuracy.

Extraction of urban road boundary based on vehicle-mounted LiDAR point cloud data

XIE Hongquan, WANG Qiuling, CAI Dongjian, XING Wanli, SUN Quan, LIU Fucheng

2021, 0(2):  64-67.  doi:10.13474/j.cnki.11-2246.2021.0045

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With the rise of high-precision map industry, accurate extraction of road boundary point cloud data has become the focus of research. In this paper, urban road data acquired by vehicle-mounted LiDAR scanning system is firstly segmented according to the collection track, and each section of road point cloud is filtered. By analyzing the elevation and plane information of the point cloud, the point cloud segmentation algorithm is used to separate the road surface from the non-road surface point cloud, and then the processed road surface point cloud is projected. Finally, the boundary feature estimation extraction algorithm is used to obtain the road boundary point cloud. Through the experimental analysis of two typical road sections, the experiment shows that this method is effective in extracting the urban road boundary point cloud, with high accuracy and robustness, which can be used for reference for the line extraction of road boundary in the future.

First flight test and accuracy evaluation of domestic dynamic gravimeter through the principle of zero length spring

ZHAI Zhenhe, FAN Haopeng, GUAN Bin, MA Jian, DUAN Weichao

2021, 0(2):  68-71.  doi:10.13474/j.cnki.11-2246.2021.0046

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CHZ-Ⅱ gravimeter is the first completely domestic airborne gravimeter through the principle of zero length spring. In April 2018, the first flight test was carried out in Weinan area of Shaanxi Province, a total of 4 sorties and 24 flight surveying lines have been completed, which markes that China's airborne gravimeter has made great progress on the road of independent research and development. Using the ground gravity data of the flying area, the accuracy of CHZ-Ⅱ gravimeter's line disturbing gravity and grid disturbing gravity data is evaluated. Under the condition of 10 km resolution, the accuracy of the surveying line disturbing gravity data is up to or better than 1 mGal by using the point-mass method. The downward continuation of 5' air grid gravity data is made by using the terrain assist method, the accuracy of the 5' grid gravity data after the downward continuation is better than 5 mGal in comparison with land gravity data, which basically meets the measurement requirement of the plain area.

GTDM: a new model for generating global tropospheric delay

MA Yongchao, Lü Zhiping, XU Guochang, CHEN Peng, YUAN Kansheng

2021, 0(2):  72-76.  doi:10.13474/j.cnki.11-2246.2021.0047

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Tropospheric delay is the main error source in GNSS positioning. Various existing tropospheric delay models have the disadvantage of overfitting, the details of delay changes in a short time. In this paper, the variation characteristics of tropospheric delay are analyzed by using the meteorological data of ECMWF from 2011 to 2017. It is found that the global tropospheric delay deviation between adjacent years of the same grid is mostly within 5 cm. Accordingly, a new tropospheric delay model GTDM is proposed. It has been verified that GTDM has a good fitting effect. In this paper, the data from 2016-2017 are used as the external compliance inspection data including the tropospheric delay product data of IGS stations provided by the IGS analysis center and the tropospheric delay calculated by the reanalysis of meteorological data by the sounding data. The results show that the accuracy of GTDM is higher than that of GZTD, GPT2w, UNB3m in global. A simple modeling method, GTDM can avoid overfitting the value of tropospheric delay and reflect the characteristics of tropospheric delay changes effectively.

Geographic information service request load balancing algorithm considering spatial access density

LIU Xiaoli, SUN Wei, LI Chengming

2021, 0(2):  77-81,166.  doi:10.13474/j.cnki.11-2246.2021.0048

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Effective load balancing is the most commonly used method to improve the response efficiency of the geographic information service request, but the existing load balancing algorithm cannot take into account the deficiency of both spatial and service request volume in the aspect of spatial service invocation. Therefore, by introducing the spatial access density and considering the relationship between the frequency of geographic information service requests and the spatial distribution of data, this paper proposes a load balancing algorithm of mass geographic information service requests based on spatial access density. Firstly, based on the geographic information data access call log, the spatial frequent range of data access is obtained and the quadtree index is constructed to establish the spatial access density equilibrium model. Then, based on the spatial access density equilibrium model, the polling allocation of geographic information service requests is carried out. Finally, by comparing the efficiency and performance experiments under the same experimental environment, the proposed algorithm can effectively improve the efficiency of geographic information service request response.

Unmanned vessel remote sensing system and its application

LEI Tianjie, ZHANG Pengpeng, HU Lianxin, WANG Shidong, SUN Liming

2021, 0(2):  82-86,92.  doi:10.13474/j.cnki.11-2246.2021.0049

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With the development of artificial intelligence technology and computer technology, the trend of intelligence and automation in the field of surveying and mapping and remote sensing has become more and more active. Following the UAV remote sensing system, the unmanned ship remote sensing system has gradually attracted the attention of the industry. As the core of future marine surveying and mapping, unmanned ship remote sensing systems will play an important role. Unmanned ships are widely used in military and civilian fields duing to the advantages of strong sensitivity, high concealment, fast running speed, and convenience. This article reviews the history and current situation of the development of remote sensing systems for unmanned ships at home and abroad, summarizes the types and functions of sensors mounted on unmanned ships platforms, reviews the processing methods of unmanned ships' remote sensing images and its application fields, further discusses the future development trend of unmanned ships. Under the background of 5G era and big data, combined with the new generation of satellite communication technology, unmanned ship remote sensing system realizes the air-space integration, which brings network, digital, Intelligent change.

A new real estate measurement method based on fusion of oblique photogrammetric real scene model data and LiDAR point cloud data

ZHAO Wenjun, DING Zhiqi, WANG Hongsen

2021, 0(2):  87-92.  doi:10.13474/j.cnki.11-2246.2021.0050

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Real estate cadastral surveying is a basic surveying and mapping work. The development of cadastral surveying techniques and methods can not only maximize the utilization rate of land in China, but also provide an efficient and convenient means for obtaining high-precision spatial data. The traditional total station and GPS RTK combined cadastral survey has the disadvantages of low efficiency and labor and financial expenditure. Based on the cadastral and immovable property survey project in the core area of the Hengkou demonstration area (test area), this paper proposes a combination of ground three-dimensional laser new scheme of mixed operation of scanning technology and tilt photogrammetry technology. The integration of the two technologies greatly improves work efficiency and data collection accuracy to meet the needs of real estate management and registration of complex space rights. Data acquisition speed is more than 4 times the traditional operation speed, Boundary point error is less than 3 cm.

Application of oblique photography in large-scale mapping of hilly and mountainous areas

HE Min, XIONG Xiancai, LI Xiaojun, ZHAO Long

2021, 0(2):  93-97,107.  doi:10.13474/j.cnki.11-2246.2021.0051

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This paper mainly discusses how to establish high-precision image model through the technical method of tilt photography, in order to meet the needs of large-scale mapping application. Firstly, by analyzing the route layout method, the key points of the control point layout and acquisition, and the key points of aerial triangulation data processing. The data model that meets the requirements of the satisfying large-scale application of surveying and mapping is established, and large scale topographic map data is obtained based on data model. Then, the test results are obtained by comparing and analyzing the accuracy with the field measurement data,the results show that the tilt photography technique can not only meet the accuracy requirements of 1:1000 large-scale mapping, but also greatly improve the work efficiency.

LiDAR and visual information fusion position system of living work robot for distribution network

REN Qingting, LI Shuai, Lü Peng, ZHANG Tong

2021, 0(2):  98-102,116.  doi:10.13474/j.cnki.11-2246.2021.0052

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This paper proposes a system based on single-line LiDAR sensor and vision fusion method to detect the spatial three-dimensional coordinates of the wire. It can improve the recognition and positioning accuracy of live working robot for distribution network effectively. LiDAR and visual information fusion position system based on radar sensors and visual fusion method to calculate the spatial three-dimensional coordinates of the wire. Living work robot can work outdoor with bright sunlight environment by using the multiple sensor fusion algorithm. At first, the LiDAR and the camera should be calibrated in advance to make the image pixels correspond to the LiDAR depth point cloud. Then, the paper uses Canny algorithm and Hough transform to calculate the position of wire. Finally, the robot can recognise and position wire in high precision and high efficiency under outdoor light.

Application of handheld LiDAR scanning system in integrated measurement of rural housing and land

NING Zhenwei, XIE Gangsheng, ZHONG Xiaolan

2021, 0(2):  103-107.  doi:10.13474/j.cnki.11-2246.2021.0053

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The real estate registration of rural houses is an important basic work for the country to deepen the reform of the rural collective property rights system. The results of real estate integration measurement are the basic data of rural housing real estate registration. How to quickly and effectively collect large-scale rural land and housing data, increase the efficiency of rural housing real estate registration and reduce the cost of data collection, is the mission and challenge of the surveying and mapping geographic information industry. This paper uses handheld LiDAR to scan and collect rural houses and attached land borrowing spatial data and attribute information in actual projects in Guangdong and Jiangsu, and compare them with traditional analytical surveying and mapping. The results show that the use of handheld LiDAR scanning for integrated premises and land data acquisition can greatly reduce the time-consuming field, improve production efficiency, reduce labor costs, and meet the advantages of large-area integrated premises and land projects. But it also has disadvantages such as equipment investment resistance.

Digital protection and VR scene construction of historical buildings in South China Historical Trail

WAN Fei, LIU Zixuan, TAN Ming

2021, 0(2):  108-111.  doi:10.13474/j.cnki.11-2246.2021.0054

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The South China Historical Trail has left a lot of cultural heritage, which is of high historical, artistic and scientific value, but the historical buildings are seriously damaged. In order to promote the activation and utilization of the South China Historical Trail, this paper adopts fine 3D modeling technology and VR technology to realize the digital protection of the South China Historical Trail. First, analyze the ruins in South China Historical Trail. Then describe the process and method of fine 3D modeling and VR scene construction for historical relics from the data collection, point cloud data processing, geometric model processing, texture mapping and other aspects. To improve the efficiency of cloud data processing an euclidean clustering point cloud segmentation algorithm based on genetic algorithm is proposed. The application results show that the 3D model and VR scene constructed in this paper can effectively restore the monuments in South China Historical Trail. It provides a new way of thinking for the protection of historical trail, ancient streets, ancient villages, red revolutionary sites and other cultural and natural landscapes.

Application of panoramic surveying technology in dynamic monitoring and monitoring of sea area

WANG Zhihao, LI Zhongzhou, TIAN Zhen

2021, 0(2):  112-116.  doi:10.13474/j.cnki.11-2246.2021.0055

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The application of LiDAR scanning panoramic surveying technology in the field of surveying and mapping in the digital age is of great significance. In this paper, dynamic Marine surveillance and monitoring in Shenzhen city is taken as an example, and data acquisition means such as ship-borne, man-mounted/vehicle-mounted mobile measurement system and high-resolution remote sensing image based on satellite and uav are comprehensively applied to obtain the Marine resource basic data with full coverage, three-dimensional, high precision and high timeliness. The convenience, effectiveness and accuracy of panoramic survey of vehicle-borne LiDAR combined with multi-temporal high-resolution image superposition analysis method in Marine surveillance and monitoring are discussed. It can not only enable surveying and mapping production units to acquire data accurately and timely in a relatively short time, but also can reduce the field survey work and the follow-up processing time of the industry, greatly improving the efficiency of survey work, which is worthy of reference and promotion.

Monitoring and analysis of surface deformation in Peibei mining region based on DS-InSAR technique

JIANG Jinxiong, DU Yuling, CHEN Yu, LIU Guang, YAN Shiyong

2021, 0(2):  117-121.  doi:10.13474/j.cnki.11-2246.2021.0056

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The conventional time series InSAR is usually limited by few and uneven spatial distributed targets of relative high coherence as well as the variable scatterring characteristics of ground surface. In this paper, the DS-InSAR technique based on coherent matrix eigenvalue decomposition(T-EVD) and Sentinel-1A imagery are employed to obtain and analyze the surface subsidence characteristics of Xuzhou Peibei mining region during the period from January 2017 to December 2018. Compared with the traditional time series InSAR method, the advantages of DS-InSAR are yielded by significantly increasing monitoring points and corresponding uniform spatial distribution, which could better reflect the complex spatial and temporal distribution characteristics of surface subsidence in coal exhausted mining regions and provide technical support for mechanism research. Therefore, DS-InSAR technique has a good application prospect in the surface subsidence monitoring over mining goaf.

Construction and application of regional atmospheric weighted average temperature model

SONG Huichuan, ZHAO Hailiang, LIU Shuailing, WANG Jinna, LI Longtong

2021, 0(2):  122-125,152.  doi:10.13474/j.cnki.11-2246.2021.0057

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The atmosphere weighted average temperature T_m is the key parameter that determines the accuracy of GPS water vapor retrieval. There are regional differences in T_m in different regions. Based on the meteorological data of Nanyang sounding station in Henan province from 2015 to 2018, the single-factor and multi-factor atmospheric weighted average temperature models suitable for Henan subtropical monsoon climate are established. At the same time, the seasonal model is constructed according to the division of the four seasons, and its accuracy is analyzed by comparing the empirical model. The results show that the accuracy of the newly established weighted average temperature model is better than that of the Bevis model as a whole. When it is applied to the inversion of GPS precipitable water at CORS station, compared with the empirical model, the newly built T_m model is more consistent with the actual precipitation, and can meet the requirements of foundation GPS precipitation inversion.

Research and implementation of urban rail transit geographic information management platform: taking Dongguan as an example

HUANG Yan, CHEN Minghui, GAO Yizhong, LI Haibo

2021, 0(2):  126-130.  doi:10.13474/j.cnki.11-2246.2021.0058

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Urban rail transit has become an effective solution to ease urban traffic congestion.The urban rail transit informatization applying GIS can effectively integrate massive spatial data and business data, visually and truly display the distribution of resources along rail transit and TOD. It can realize land-use analysis and full-cycle refined management, provide scientific decision-making assistance for managers.Thereby it can improve the comprehensive level of rail transit construction and refined management. The geographic information management platform of Dongguan rail transit and TOD is implemented by using the technologies of GIS, 2D and 3D integration in this paper. It realizes the graphics-attributes integration management for rail transit information of the above-ground, ground and underground, lays a solid foundation for the intelligent development of urban rail transit.

On the quality inspection software system of surveying and mapping geographic information achievements under “five dimensional synergy”

ZHANG Libo, ZHANG Jixian, HAN Wenli, GE Juan, SHEN Jing, LU Yao

2021, 0(2):  131-135,143.  doi:10.13474/j.cnki.11-2246.2021.0059

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Quality inspection software is an important means of quality inspection and an important factor affecting quality inspection work. Facing the current situation and problems of quality inspection software for surveying and mapping geographic information achievements, and combining existing means and new technology, this paper puts forward a software system for quality inspection of surveying and mapping geographic information achievements under "five dimensional synergy", which is composed of achievement dimension, project dimension, big data dimension, intelligence dimension and history dimension, expounds the work contents of surveying and mapping geographic information results quality inspection in various dimensions, introduces the relationship of business process and data flow between the five dimensions. It provides the idea for the future research content and development direction of Surveying and mapping geographic information results quality inspection software.

Analysis on Ning-Zhen-Yang region impervious surface area growth pattern

SHI Xiaofeng, XIONG Kejun, LU Gang, QIU Qianqian

2021, 0(2):  136-139.  doi:10.13474/j.cnki.11-2246.2021.0060

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Impervious surface has caused significant reduction in the process of urbanization. This research introduces the changing trajectory of impervious surface and growth pattern to investigate the spatio-temporal evolution of impervious surface in a case study in Ning-Zhen-Yang region. The results show that the urbanization process has driven impervious surface expanded continually during the study period, in which 301 km² of natural or semi-natural landscape is changed into impermeable landscape, with an average annual growth rate of 0.44%. The changing pattern of impervious surface has shifted from Zhenjiang to Nanjing in 2017, which means Zhenjiang grows severely before 2017, and Nanjing increases drastically after 2017. Moreover, the changing trajectory of impervious surface is mainly a one-time change. Such change is accelerating after 2017, and the vegetation is the primary source for urban expansion. The impermeable surface has spread to the urban fringe rapidly, which is the dominant growing mode in this region. Thus, an effective urban control is necessary to lead the development of urban boundary.

Environmental monitoring system and its application for UAV aviation radioactive resources exploration

XIAO Bin, FAN Junlin, YANG Qinghua

2021, 0(2):  140-143.  doi:10.13474/j.cnki.11-2246.2021.0061

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Aiming at the problems of high risk of flight operation and vulnerable safety of pilots in aviation radioactivity survey industry, and considering the integration of UAV platform, task sensor and data acquisition and processing software, the integrated design of multi load including structure design, electrical design, control flow design has been realized, a new and portable unmanned aerial vehicle (UAV) airborne radioactive resources survey environmental monitoring system has been developed, it can be used in large scale (more than 1:50 000) radioactive mineral exploration, environmental monitoring, radioactive evaluation and other production work. The experimental results show that the data is stable and reliable, and has great application value. The research and development of this system has filled the blank of the domestic low space energy spectrum detection technology.

Construction of “one map” of agriculture and analysis of comprehensive data

XIA Lanfang, CHEN Xu

2021, 0(2):  144-148.  doi:10.13474/j.cnki.11-2246.2021.0062

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One map of Shanghai agricultural establishes a "virtual agricultural and rural geographical environment" through geographic information technology, gathers multi-source agricultural geographic information data. It has formed a rich agricultural geographic information big data, which takes agricultural land as the unique identification code and connects various agricultural thematic information on the basis of agricultural land. In order to strengthen the data sharing and application, OGC standard service interface and customized spatial information service interface are provided.It provides unified agricultural geographic information support services for all business systems, including WMS services and WFS services. Through the analysis of agricultural comprehensive big data, it can provide data support for the development of green agriculture and the structural reform of agricultural supply side.

Application analysis of underground pipeline modeling based on BIM technology

REN Lifu

2021, 0(2):  149-152.  doi:10.13474/j.cnki.11-2246.2021.0063

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With the continuous development of urbanization, underground pipeline laying is more intensive, this situation will lead to a variety of security risks, threatening the safety of people's lives at any time. Today's urban management is basically based on two-dimensional means to achieve the later construction and operation and maintenance management needs, which restricts the accuracy of pipeline data results, and can not guarantee the unity of two-dimensional pipeline data to the actual situation. By introducing and mastering BIM technology, in underground engineering can provide three-dimensional visualization and information service for managers, and can solve the problem of urban life security more conveniently. There is an example of a practical project application of BIM technology in underground pipeline engineering in this paper, so that BIM technology can play its value in underground engineering and provide effective technical support for managers.

Research on automatic downsizing and updating of cross scale level based on topographic map database

XIANG Hongmei

2021, 0(2):  153-156,160.  doi:10.13474/j.cnki.11-2246.2021.0064

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In order to meet the requirement of updating other scale topographic maps with 1:500 topographic map, a method of automatic downsizing and updating at the same scale level and across scale level based on topographic map database is proposed.Through the design of topographic map template and transition template, defining the conversion rules of comprehensive feature elements, developing automatic downsizing software module, customizing the task of automatic downsizing and updating, automatically downloading the topographic map data by using the survey update range line in the database for downsizing and updating, Which realize the goal of successively downsizing and updating large-scale topographic map to obtain various scale topographic maps.The technical method proposed in this paper has been verified in the updating of urban basic geographic information database of Changsha city, which provides technical experience for rapid acquisition of diverse geographic information data by downsizing.

Teaching practice and reform of pattern recognition course of remote sensing major in the era of satellite+AI

LI Erzhu, KANG Jianrong, ZHANG Lianpeng

2021, 0(2):  157-160.  doi:10.13474/j.cnki.11-2246.2021.0065

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In the era of artificial intelligence (AI) and deepening the development of the remote sensing industry, the training of remote sensing professionals needs to keep pace with the times and improve the ability of AI applications. Aiming at the current situation and existing problems of patterning recognition teaching as one of the core AI courses of remote sensing and technology, an application-oriented pattern recognition course construction idea is proposed for remote sensing major. Specifically, a teaching program is designed to improve the ability of AI applications from two aspects of teaching and practice content. From the results of teaching feedback, the teaching ideas proposed in this paper have stimulated students' interest in pattern recognition course and improved their ability to use pattern recognition methods in interpreting remote sensing information.

3D reverse modeling of unmanned aerial vehicle tilt photography with laser scanner

GAO Limin, LI Junjie, LI Wenqing, XU Gang

2021, 0(2):  161-163.  doi:10.13474/j.cnki.11-2246.2021.0066

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With the continuous improvement of science and technology in recent years, urban 3D digitization has always been the key application direction of digital city construction.With the development of UAV remote sensing technology and 3D laser scanning technology, digital city construction has gradually turned to automation and intelligence.In this paper, Topcom Falcon 8 multi-rotor UAV combined with topcom GLS-2000L 3D laser scanner is used to collect data from buildings, and Context Capture automatic modeling and post-processing software is used to perfectly solve the technical problem of automatic 3D urban modeling, thus providing strong technical support for the construction of 3D system of smart city.

Rapid extraction method of building facade in urban redevelopment

LI Zhiyuan, LI Digui, WANG Jian, SONG Yu

2021, 0(2):  164-166.  doi:10.13474/j.cnki.11-2246.2021.0067

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Aiming at the problem of urban redevelopment in modernization construction, traditional measurement methods are not only low in measurement efficiency, but also cannot accurately obtain all the information of the building facade for buildings with complex structures. There are incomplete measurement and low modeling efficiency. This article first uses 3D laser scanning technology to obtain massive point cloud data, which contains all the 3D information of the building; then uses multiple modeling platforms to work together, combined with real photos, to perform 3D reconstruction of complex buildings to obtain facades of the target building in all directions; compared and analyzed the model data with the field point cloud data and the actual building height, which can not only obtain accurate quickly, true and comprehensive facade information of the building, but also improve work efficiency and provide detailed and reliable information for the construction and planning of smart cities.