Table of Content

20 June 2022, Volume 51 Issue 6

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Academician Forum

A new generation of intelligent mapping and remote sensing scientific test satellite Luojia-3 01

LI Deren, WANG Mi, YANG Fang

2022, 51(6):  789-796.  doi:10.11947/j.AGCS.2022.20220184

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With the continuous improvement of the performance and the increasing variety of optical mapping and remote sensing satellites, they have become an important support for obtaining global accurate surveying and mapping remote sensing information. At present, optical mapping and remote sensing satellites already have sub-meter spatial resolution capabilities, but there is a serious lag problem in mapping and remote sensing information services. It is urgent to develop intelligent mapping and remote sensing satellites to promote the transformation and upgrading to real-time intelligent services. Firstly, based on the three imaging systems of the optical mapping and remote sensing satellites and their realization methods and application characteristics, this paper analyzes the applicable system of the intelligent mapping and remote sensing satellites. Further, according to the application requirements of real-time, intelligence and popularization, puts forward the design concept of integrated intelligent remote sensing satellite integrating communication, navigation and remote sensing and focuses on the service mode and integrated function composition of intelligent remote sensing satellite. Then expounds the performance and characteristics of Luojia-3 01 satellite, a new generation of intelligent surveying and mapping remote sensing scientific test satellite. And finally summarizes and prospects the development and mission of intelligent mapping remote sensing satellite. Luojia-3 01 satellite integrates remote sensing and communication functions. It explores an efficient and intelligent service mode of mapping and remote sensing information from data acquisition to application terminal, and provides a real service verification platform for on-orbit processing and real-time transmission of remote sensing data based on space-ground internet, which is of great significance to the construction of China's spatial information network.

Introduction to the second geodetic boundary value problem

WEI Ziqing

2022, 51(6):  797-803.  doi:10.11947/j.AGCS.2022.20220067

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In space geodesy time, GNSS is capable of determining geodetic heights for ground points, enabling gravity disturbances to be direct observables. As a result, the second geodetic boundary value problem(GBVP)with gravity disturbances as the boundary condition can be applied in geodesy. The combination of its solution with GNSS is becoming a new approach to measuring the elevation above sea level, which is expected to have a bright future in application. The paper briefly discusses in principle the spherical approximation the 2nd GBVPs with two different boundary surfaces. The first kind uses the topographic surface as the boundary, and gives the analytical continuation solutions of surface height anomalies and deflections of the vertical. The second kind, with the surface of the reference-ellipsoid as the boundary, first moves topographic masses outside the reference ellipsoid onto it according to the Helmert's second condensation method, and then convolutes the Hotine function with Helmert gravity disturbances at the boundary, which are analytically downward-continued from the earth's surface, and after considering the indirect effects of topography gives finally the Helmert solutions of geoidal heights, ellipsoid vertical deflections, height anomalies and surface deflections of the vertical. In the discussion part a comparison between the 2nd GBVP and the 3rd GBVP is made, and an approach is presented to converting the orthometric or normal height into the geodetic height for existing gravity points, and the application prospect of the 2nd GBVP is looked into the future.

Development and progress of satellite photogrammetry in China

WANG Renxiang, WANG Jianrong

2022, 51(6):  804-810.  doi:10.11947/j.AGCS.2022.20220043

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Satellite photogrammetry is a new means of obtaining geospatial information data, and it plays an important role in the global basic surveying and mapping. In this paper, the author reviewed the two stages of the development of satellite photogrammetry from personal experience in our country. Then, the theory of aerial triangulation adjustment for linear array push-broom image is mainly introduced. Finally, based on the engineering practice of TH-1 satellite, it is shown that through our independent theoretical innovation, the high location accuracy without ground control points (GCPs) can be achieved using single strip linear array stereo images, which can also reach the theoretical level of frame camera images.

PNT intelligence and intelligent PNT

LIU Jingnan, LUO Yarong, GUO Chi, GAO Kefu

2022, 51(6):  811-828.  doi:10.11947/j.AGCS.2022.20220152

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Positioning, navigation and timing (PNT) are spatio-temporal location concepts closely related to economic and social activities generated by human beings after long-term perception and cognition of the universe and the relationship with human existence. PNT is also the intelligence that the matter, energy and information on the earth have evolved over hundreds of millions of years to perceive, recognize and position related to space-time, which is called PNT intelligence or space-time intelligence. Intelligence is the sum of the ability to seek benefits and avoid harm that has been inherited and evolved from generation to generation in order to adapt to the environment. It can be called natural intelligence. In this paper, the characteristics of natural intelligence based on the material basis of living body are analyzed, and the characteristics of PNT intelligence of living body are discussed. This paper summarizes the latest achievements, trends and enlightenment of human research on PNT intelligence in living organisms. Among them, interactive intelligence and PNT intelligence played a key role in the evolution of living organisms from lower level to higher level, especially in the evolution of Homo sapiens and the formation of human civilization. With the development and integration of natural intelligence, PNT intelligence and artificial intelligence, the development of PNT technology has entered the stage of intelligent PNT. This paper focuses on the concept, connotation and development trend of intelligent PNT, and discusses the latest progress and influence of intelligent hot topics from two aspects of PNT application and spatio-temporal information infrastructure construction. On this basis, some thoughts and prospects for the development of intelligent PNT are also put forward.

Cartography：its past, present and future

WANG Jiayao, WU Fang, YAN Haowen

2022, 51(6):  829-842.  doi:10.11947/j.AGCS.2022.20210661

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Currently, cartography, as well as other disciplines such as geography, is at a time of great revolution. While cartography is making progress continuously, various "trend of thoughts" and "points of view" appear, such as "is cartography marginalized?" and "where should cartography go?" These arise great concerns in the circles of both academy and industry of geoinformation. To answer the questions, firstly, this paper briefly introduces the development history of cartography, including reviewing the three times of rise in the history of cartography. It is not forgetting the past that can go to the future successfully. A review of the history of cartography is for the purpose of making cartography walk to the future better. Secondly, the achievements of contemporary cartography are analyzed, including the discipline systems of cartography, new minds, new thoughts and new methods in cartography, intelligent map generalization and cascade renewal of multiscale maps, social influences of maps, and inexhaustible driving forces of cartography development. It is to know present that can start a good future. Finally, to play the leading role of cartographic philosophy in innovative development of cartography, the paper addresses the development of cartography promoted by artificial intelligence and the achievements in visualization of spatio-temporal big data and visual design. It deems that cartography will certainly develop at an integrated direction of both high differentiation and high synthetization, and the rerise of cartography is the great trend of the time.

Development and application of industrial photogrammetry technology

ZHANG Zuxun, ZHENG Shunyi, WANG xiaonan

2022, 51(6):  843-853.  doi:10.11947/j.AGCS.2022.20220064

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In the trend of automation, flexibility and intelligence in the manufacturing industry, traditional industrial measurement technology is difficult to meet the requirements of high precision, high efficiency and high convenience at the same time. This paper proposes a measurement system based on industrial photogrammetry technology, has the characteristics of real-time, convenience, automation and intelligence. The high-quality 3D data obtained by it can be used in typical industrial application scenarios such as reverse engineering, quality inspection, and auxiliary intelligent manufacturing. This paper also introduces the technical route of the measurement system, and puts forward new insights from the aspects of hardware design and algorithm optimization.

Development of integrated and intelligent surveying and mapping satellite project with corresponding key technology

YANG Yuanxi, REN Xia, WANG Jianrong

2022, 51(6):  854-861.  doi:10.11947/j.AGCS.2022.20220048

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Satellite remote sensing has become the main method of global earth observation. In this paper, the geodetic satellites are briefly summarized at first. The contribution and problems of satellite photogrammetry of China are specially analyzed. The development trend of earth observation satellites is analyzed, and the emphases are on the possibility and technical bottlenecks of comprehensive surveying and mapping satellites with integrated payloads. It is generally considered that the observation efficiency is high with single integrated surveying and mapping satellite, while the overall observation benefit is limited. The possibility and key technologies of earth observation with intensive micro satellite constellation are analyzed, including payloads modular design, satellite miniaturization design, satellite optimal configuration technology, data transmission technology, the elastic allocation technology for satellites in-orbit and on-board data fast processing technology etc. The prospective of intelligent observation satellite is prospected, and the corresponding key technologies are analyzed, including the technologies of on-board observation intelligent identification, inter-satellite and satellite-earth intelligent transmission, on-board and ground intelligent data processing, etc. In addition, the intelligent obstacle avoidance of satellite, intelligent tracking and intelligent control of launch vehicle landing location are also the development directions to be considered in satellite observations.

New generation SAR for Earth environment observation

GUO Huadong, WU Wenjin, ZHANG Ke, LI Xinwu

2022, 51(6):  862-872.  doi:10.11947/j.AGCS.2022.20220098

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Synthetic aperture radar (SAR) systems have the unique advantage of all-time and all-weather observation. In the past decade or so, with the continuous announcement of multi-mode, multi-angle, multi-dimension, wide-swath, high-resolution, and multi-static SAR observation technologies, SAR observation has been in the "new generation" stage. This paper first introduces the development of the observation capability of the new generation SAR, including how to realize the wide-swath, multi-temporal, and multi-level observation as well as moon-base observation; Then, the development and application of new information extraction methods such as the non-stationary statistical modeling, time-frequency decomposition, deep learning, and compressed sensing for new generation SAR images are summarized; Finally, recent application progress in urban management, vegetation mapping, polar region and ocean survey, and disaster monitoring are listed to promote wider and deeper applications of the new generation SAR.

Deep learning interpretability analysis methods in image interpretation

GONG Jianya, HUAN Linxi, ZHENG Xianwei

2022, 51(6):  873-884.  doi:10.11947/j.AGCS.2022.20220106

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The rapid development of deep learning has greatly improved the performance of various computer vision tasks. However, the "black box" nature of deep learning network models makes it difficult for users to understand its decision-making mechanism, which is not conductive to model structure optimization and security enhancement and also greatly increases the training cost. Focusing on the task of intelligent image interpretation, this paper makes a comprehensive review and comparison of the research progress of deep learning interpretability. Firstly, we group the current interpretability analysis methods into six categories: activation maximization method, surrogate model, attribution method, perturbation-based method, class activation map based method and example-based method, and review the principle, focus, advantages, and disadvantages of existing related works. Secondly, we introduce eight evaluation metrics that measure the reliability of the explanations provided by the various interpretability analysis methods, and sort out the current publicly available open source libraries for deep learning interpretability analysis. Based on the open source library, we verify the applicability of the current deep learning interpretability analysis methods to the interpretation of remote sensing images. The experimental results show that the current interpretability methods are applicable to the analysis of remote sensing interpretation, but have certain limitations. Finally, we summarize the open challenges of using existing interpretability algorithms for remote sensing data analysis, and look forward to the prospect of designing interpretability analysis methods oriented to remote sensing images. We hope this review can promote the research on interpretability methods for remote sensing image interpretation, so as to provide reliable theoretical support and algorithm design guidance for the application of deep learning technology in remote sensing image interpretation tasks.

Geodesy and Navigation

Technical progress and development trend of geological hazards early identification with multi-source remote sensing

ZHANG Qin, ZHAO Chaoying, CHEN Xuerong

2022, 51(6):  885-896.  doi:10.11947/j.AGCS.2022.20220132

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With the intensification of global climate change mineral resource exploitation and human engineering activities, the geological disasters including ice collapse, collapse, landslide, land subsidence and ground fissure are triggered with the trend of high frequency and in chain mode, which result in serious consequence. The early identification of geological disasters in large area and with high efficiency is the prerequisite for the hazard mitigation and prevention and the technical support of the engineering safety. In this paper, the characteristics of diverse geological disasters and traditional methods of their identification are introduced firstly. Then we focus on optical remote sensing, synthetic aperture radar, LiDAR and the fusion of multi-source remote sensing, where the technical flow and typical applications are given. Lastly, the current difficulties and the future trends are summarized and forwarded.

The lunar shape and its gravity field

LI Fei, ZHENG Chong, YE Mao, HAO Weifeng, DENG Qingyun, ZHANG Wensong, ZHENG Yingjun, YAN Jianguo, BARRIOT Jean-Pierre

2022, 51(6):  897-908.  doi:10.11947/j.AGCS.2022.20220139

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This paper reviews the research progress, acquisition methods and representative results of lunar shape and its gravity field from the perspective of the application of surveying and mapping science and technology in lunar exploration. Moreover, the main problems and proposed solutions in the existing lunar DEM and gravity field models are presented. Finally, the opportunities and challenges in lunar shape and its gravity field research are prospected in the perspective of the lunar exploration programs of other countries and the ongoing fourth step of Chang'e project in China.

Research and application of indoor visible light communication positioning technology

LI Guangyun, SUN Senzhen, WANG Li, FENG Qiqiang

2022, 51(6):  909-922.  doi:10.11947/j.AGCS.2022.20220007

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The technology of visible light positioning (VLP) has the advantages of low cost, high precision, no electromagnetic interference, convenient deployment, and the advantage of taking into account both communication positioning and lighting which makes this technology has potentially useful application prospects in the field of indoor positioning. In this paper, two indoor positioning methods based on visible light communication (VLC) called imaging and non-imaging method are summarized, meanwhile, their key technologies, research development,applications and trend are analyzed and discussed. A VLP light source matching identification method based on autocorrelation sequence is proposed, what's more, a method of constructing a positioning system based on the common imaging sensor and rectangular flat-panel light source is introduced. Finally, the research and development direction of indoor VLP technology is prospected.

Research progress of ocean satellite altimetry and its recovery of global marine gravity field and seafloor topography model

SUN Zhongmiao, GUAN Bin, ZHAI Zhenhe, OUYANG Mingda

2022, 51(6):  923-934.  doi:10.11947/j.AGCS.2022.20220069

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Marine satellite altimetry is very important in the fields of geodesy, such as global and regional geoid modeling, global marine gravity field inversion, seafloor bathymetry, sea level change monitoring and tectonic plate motion research and so on. This paper summarizes the brief history of marine microwave altimetry satellite, and focuses on the rich achievements of satellite altimetry in the global marine gravity field and global bathymetry model, in which the main models are compared and analyzed. Three advanced microwave altimetry technologies such as synthetic aperture radar altimeter, Ka-band radar altimeter and synthetic aperture radar interferometer are introduced, and their advantages and disadvantages are analyzed. It shows that these three technologies will be developed in parallel in the next few years. This paper systematically expounds the research trends of another new technology of ocean satellite altimetry, namely GNSS reflected signal measurement technology, and gives the development context and development trend of GNSS reflectometry (GNSS-R) experimental satellites. One of the development direction of satellite altimetry is using the observation network consisted of multiple altimetry satellites. It outlines several earlier and newly proposes constellation altimetry plans, and briefly introduces the two-satellite tandem mode altimetry plan proposed and being implemented in China. Finally, several main concerns in the development of satellite altimetry are pointed out, including two-dimensional sea surface height (or differential height) measurement using the two-satellite tandem mode altimetry or SWOT (surface water ocean topography) mission, the combination of bathymetry model derived from satellite altimetry and advanced topographic laser altimeter observation data and remote sensing satellite images , the carrier phase measurement of the centimeter-level sea surface height by on-board GNSS-R, and the potential application of artificial intelligence technology in satellite altimetry.

Research progress and prospect of monitoring tropospheric water vapor by GNSS technique

YAO Yibin, ZHAO Qingzhi

2022, 51(6):  935-952.  doi:10.11947/j.AGCS.2022.20220039

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Troposphere is the most closely related to human activities in the geospace environment, and water vapor is one of the most important components in the lower atmosphere. Although water vapor accounts for a small proportion in the troposphere, it plays an important role in a series of weather and a variety of climate changes. With the rapid development of GNSS (global navigation satellite system), GNSS water vapor monitoring has become one of the most important research and application directions. This paper systematically introduces the research status and progress of GNSS multi-dimensional water vapor monitoring and its application in related fields. In terms of GNSS water vapor monitoring, the current research mainly focuses on two-dimensional precipitable water vapor monitoring and three-dimensional wet refractive index or water vapor density profile retrieval. In terms of GNSS water vapor application research, it mainly includes GNSS positioning, short-term rainfall, drought and flood monitoring, numerical assimilation prediction and so on.

Photogrammetry and Remote Sensing

A review of Antarctic ice velocity products and methods based on optical remote sensing satellite images

LI Rongxing, LI Guojun, FENG Tiantian, SHEN Qiang, QIAO Gang, YE Zhen, XIA Menglian

2022, 51(6):  953-963.  doi:10.11947/j.AGCS.2022.20220168

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Ice velocity is a direct and essential indicator of the stability of Antarctic ice sheet in response to global climate change. It is also one of the crucial data to accurately estimate the contribution of the Antarctic ice sheet to global sea level rise. Optical remote sensing imagery is an important data source for large-scale extraction of Antarctic ice velocity because of the advantages of data acquisition in fine temporal and spatial resolution. In this paper, we review the existing methods of Antarctic ice velocity reconstruction by using optical images, introduce relevant software and tools, and summarize Antarctic ice velocity products generated based on optical remote sensing images from 1960s to present. Furthermore, we demonstrate applications of the ice velocity products in some typical areas, such as mass balance evaluation, long time series changes monitoring of ice shelves, etc. Finally, the advantages and future development trends of optical remote sensing images for Antarctic ice velocity reconstruction are summarized.

Advances of spaceborne laser altimetry technology

SHAN Jie, TIAN Xiangxi, LI Shuang, LI Renfei

2022, 51(6):  964-982.  doi:10.11947/j.AGCS.2022.20220174

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Spaceborne laser altimetry technology has become one of the main technologies for all-round global observation. Its high accuracy, all-day capability, and efficient three-dimensional measurement constitute unique advantages for many scientific studies. This paper systematically discusses the working principles and data processing methods of two current spaceborne laser altimetry technologies. The description is also extended to representative applications of spaceborne laser altimetry data in earth and planetary sciences. Finally, the paper presents a brief prospect for future directions and developments of spaceborne laser altimetry. It is expected that this paper will be beneficial to colleagues and professionals who are engaged in research, development and applications of spaceborne laser altimetry technology.

Research progress of "penetration mapping" of earth surface by PolInSAR

ZHU Jianjun, FU Haiqiang, WANG Changcheng

2022, 51(6):  983-995.  doi:10.11947/j.AGCS.2022.20220154

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Traditional optical remote sensing mainly collects surface geometric information and partial physical information, which is difficult to monitor their thickness and internal structural attribute information. PolInSAR (polarimetric SAR interferometry) characterized by the ability to penetrate the surface cover can record internal structures and physical properties, bringing opportunities to solve the above problem. Therefore, how to perform "penetration mapping" to the surface cover to fully collect the spatial geometry, internal structural properties and its dynamic change process have become a research hotspot. This article tries to define the connotation of "penetration mapping". Then the PolInSAR application progress of the natural surface cover of vegetation, ice and the desert are combed. Finally, we analyze and summarize the current problems and challenges faced by PolInSAR penetration mapping.

Optimized views photogrammetry and its precision analysis

LI Qingquan, HUANG Hui, JIANG San, HU Qingwu, YU Wenshuai

2022, 51(6):  996-1007.  doi:10.11947/j.AGCS.2022.20210685

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UAV path planning and accurate data acquisition is a key problem for 3D reconstruction of complex urban scenes. By using the rough model of the object to be captured, optimized views photogrammetry combines the technique of dense sampling-based initial view generation and reconstructability constrained view optimization and achieves the purpose of precious 3D model reconstruction from the least number of images. First, this study presents the principle of optimized views photogrammetry. Second, data acquisition campaigns of real scenes are conducted with the aid of optimized views photogrammetry. Combining laser scanned point clouds, the assessment of 3D reconstruction precision and mesh model quality is performed. Experimental results verifies that for the building facades that are hardly observed from oblique photogrammetry views, the mesh model quality is improved dramatically with the increase ratio of 3 to 5 times. In addition, compared with traditional oblique photogrammetry, optimized views photogrammetry can establish stable image connection network and achieve competitive precision in absolute bundle adjustment.

Key problems of remote sensing images intelligent service for constellation

WANG Mi, WU Qianyu

2022, 51(6):  1008-1016.  doi:10.11947/j.AGCS.2022.20220186

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The all-day, all-weather and global real-time intelligent service of remote sensing information is the goal of earth observation system construction. In recent years, with the development of domestic high-scoring special projects and commercial satellites, the number of on orbit satellites has increased dramatically, and the earth observation capability has been greatly enhanced, which makes the operation control, reception, processing and application service mode of the traditional single satellite and constellation satellite systems face severe challenges. It is urgent to plan the resources of all aspects of satellite application, give full play to the advantages of multi-satellite collaboration, and build a unified remote sensing images real-time intelligent service system. According to the characteristics of remote sensing constellation satellite system and the demand characteristics of earth observation users, this paper studies the key problems of remote sensing image intelligent service for constellation. This paper proposed a task oriented global multi-scale semantic description grid to coordinate the global dynamic and static task semantic description. On this basis, it focuses on the key technical problems such as autonomous task management, intelligent planning and multi satellite collaborative intelligent service. Formed a constellation intelligent service technology system integrating mission control, mission planning, on-orbit processing, data download and distribution. By giving full play to the advantages of constellation collaboration, combining on-orbit processing and artificial intelligence technology to reduce the time delay of each link and improve the data processing accuracy. So as to achieve fully automated and intelligent near real-time constellation intelligent services, and lay the foundation for all-day, all-weather, fast and efficient intelligent services for earth observation.

Cartography and Geoinformation

Geo-information security technology: progress and prospects

ZHU Changqing, REN Na, XU Dingjie

2022, 51(6):  1017-1028.  doi:10.11947/j.AGCS.2022.20220172

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With the in-depth utilization of geographic information, the conflicts in geographic information become severe between the requirements of high-precision wide-security-range protection and the requirements of sharing from current economy development. Therefore, sharing geographic information to the maximum under safe conditions has become an important issue, which is to be solved urgently. Consequently, the reliable protection techniques are in urgent demand for protecting the security of geographic information. In this paper, the recent progress of security techniques for geographic information has been reviewed, including the encryption techniques to convert the data into cipher text, the digital watermarking techniques for copyright protection and traceability, the security control techniques for term of validity and permission, the confidential treatment techniques for reducing the data precision and deleting the security property, and the certifiable block chain techniques for tamper proof. Then, the utilization of security techniques in protection for geographic information is discussed. Finally, the future developing direction and the key problems to be further solved are prospected for security techniques of geographic information.

Yesterday, today and tomorrow of autonomous navigation maps

MENG Liqiu

2022, 51(6):  1029-1039.  doi:10.11947/j.AGCS.2022.20220198

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Taking the evolutionary background of driverless technology as the starting point, this paper reviews the concept of autonomous navigation maps, i.e., high definition maps or HD maps, along with their content components, data sources and differences from ordinary navigation maps. On this basis the author introduces the main modules of the HD mapping process, including data acquisition and update of the a priori map layer, real-time construction of the dynamic map layer, edge computing, data standardization and compression services. Four main research bottlenecks are highlighted: ① automatic modeling of complex driving environments; ② data acquisition for corner cases; ③ navigation decisions in ethical dilemmas; ④ safety performance evaluation of driverless technologies. These bottlenecks are challenging the limits of autonomous navigation capability of HD maps from different perspectives, and demand a global collaboration among government legislatures, related enterprises, research institutions, and the public. With the continuous improvement of driverless technology, the focus of safety-first research will gradually expand into a mobile experience that balances safety and trustworthiness, environmental protection and energy saving, and physical and mental pleasure. The structured digital code of HD maps will be customized to a diverse range of high legibility maps for the human eye. How to leverage the cost-effectiveness of navigation data, generate high precision maps and high legibility maps in real time, and provide optimal services for both machines and humans will become a new research hotspot.

From real 3D modeling to digital twin modeling

ZHU Qing, ZHANG Liguo, DING Yulin, HU Han, GE Xuming, LIU Mingwei, WANG Wei

2022, 51(6):  1040-1049.  doi:10.11947/j.AGCS.2022.20210640

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From real 3D modeling to digital twin modeling is the basic requirement for the construction and development of the country's digital economy and smart society. This paper discusses the connotations and key technologies of real 3D modeling and digital twin modeling, and introduces three typical application scenarios: digital villages, future communities and intelligent railways. Wide-area real 3D modeling is facing challenges in low-cost and efficient data collection and intelligent automated modeling and dynamic updating. There are still key technical bottlenecks in the integrated expression of all-element holistic representation data and mechanism models for digital twin modeling at the city level or major engineering level. Surveying and mapping technology is in urgent need of multi-disciplinary cross-integration innovation, breakthroughs in organic collaboration between the sky and the ground, real-time and dynamic acquisition of multi-detailed real 3D data, automated intelligent processing of multi-specialty, multi-scale and multi-modal spatio-temporal data, and detailed 3D construction of complex scenes under incomplete data conditions. Core key technologies such as dynamic construction of full-life-cycle digital twin models that combine characterization data and mechanism models to form general geospatial intelligence to achieve high-quality development of surveying and mapping technology and an irreplaceable and more powerful basic support for economic and social development.

Research progress on geospatial service web and gollaboration

WU Huayi, JIN Fengying, LIANG Jianyuan, ZHANG Xianyuan, XING Huaqiao, GUI Zhipeng, LI Rui, XIANG Longgang

2022, 51(6):  1050-1061.  doi:10.11947/j.AGCS.2022.20210338

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The rapid development of the Internet and big data technology provided a technical foundation for the share and widespread use of the geospatial service (or GIService). Facing a large amount of multi-source, heterogeneous and massive geospatial services, it is a big challenge to organize these services and provide service compositions efficiently in order to expand the application scope, which has caught much attention of the scientists. Constructing the geospatial service web (GSW) and realizing semantics-based service collaboration is a potential solution to these issues. This paper analyzed the current development of the geospatial service and the GSW. Based on the achievements of the construction, expression, optimization, and service collaboration in the service network domain, we discussed several potential approaches of the GSW as well as GSW-based service collaboration. Finally, several technical challenges and research directions to construct GWS and service collaboration were proposed.

A note on GeoAI from the perspective of geographical laws

LIU Yu, GUO Hao, LI Haifeng, DONG Weihua, PEI Tao

2022, 51(6):  1062-1069.  doi:10.11947/j.AGCS.2022.20220125

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Recently, the rapid development of artificial intelligence has reshaped the research paradigm of many disciplines. Regarding geography, this trend is no exception. From the perspective of knowledge discovery, geographical research has two major tasks: revealing big unknowns and discovering laws. Artificial intelligence helps geographers discover knowledge or even automatically extract knowledge from these two aspects. Compared with other geoscience disciplines, geography focuses more on discovering "universal" laws. However, in the process of seeking geographical laws, we need to deal with the trade-off between universality and geographical heterogeneity, the core in which can be expressed as the theoretical foundation in artificial intelligence learning: generalization and interpretability. Therefore, there is an inherent logical consistency between the two disciplines. Introducing artificial intelligence to geographical studies will help to strengthen the disciplinary basis. This paper gives an example framework for artificial intelligence to discover geographical laws, and points out the future directions of geospatial artificial intelligence and geographic information science.

Road crowd-sensing with high spatio-temporal resolution in big data era

TANG Luliang, ZHAO Zilong, YANG Xue, KAN Zihan, REN Chang, GAO Jie, LI Chaokui, ZHANG Xia, LI Qingquan

2022, 51(6):  1070-1090.  doi:10.11947/j.AGCS.2022.20220155

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As one of the most important, complex, and typical carriers in the evolution of human development, the road scene is a complex of road infrastructure and activity behavior, linking and constructing the "man-land relationship". Road scene perception has developed from two-dimensional abstraction to three-dimensional refinement, from static past tense to dynamic present tense. It has become the key technical support for smart cities, intelligent transportation, and autonomous driving, and is the core technical guarantee for China's new urbanization strategy and strong transportation strategy. Based on spatio-temporal traffic data, this paper proposes a new method for road crowd-sensing with high spatio-temporal resolution based on static infrastructure "form" and dynamic activity behavior "flow". From the perspective of static road network "form", the method takes "point-line-surface-body" elements as the research context, and constructs a theoretical system of high-precision road map crowd-sensing. In terms of activity behavior "flow", we break through the limitations of traditional point pattern analysis and develop a spatio-temporal modeling and multi-scale analysis method for spatial activity flow. In this paper, we reveal the evolution pattern of road scenes under the interaction of static infrastructure "form" structure and dynamic activity behavior "flow" pattern. Furthermore, we develop a road crowd-sensing theoretical system in which "form" controls "flow", "flow" determines "form", and "form" overlaps "flow", to provide core technology and data support for the development of smart cities and intelligent transportation.