With the continuous development of surveying and mapping science and computer technology, modern digital surveying and mapping technology represented by global positioning satellite (GPS) technology, aerial remote sensing (RS) technology, digital surveying and mapping technology, geographic information system (GIS) and communication network technology has been widely used in the field of surveying and mapping, and gradually replaced the traditional surveying and mapping technology. Surveying and mapping industry is experiencing a historic transformation from traditional geographic information industry to modern geographic information industry. In order to ensure the sustainable development of surveying and mapping technology, Shenzhen actively promoted the application of new technologies and methods, focused on building a digital surveying and mapping technology system, developed a digital surveying and mapping system with completely independent copyright, and developed and applied CBW-CE handheld electronic tablet in the dynamic revision of topographic maps, which made the city's digital surveying and mapping technology reach a new level and accumulated rich experience for the development of high-tech surveying and mapping in engineering surveying and mapping and geological prospecting industries.
Second, the construction of digital mapping technology system
In the 1990s, the surveying and mapping industry in Shenzhen followed closely the development of surveying and mapping technology, combined with the actual situation in Shenzhen, updated equipment in time and purchased automatic instruments (such as GPS, total station and digital level). ), introduce or develop the software or system needed for digital surveying and mapping, and actively promote the application of new surveying and mapping technologies and methods represented by "3S(GPS, RS, GIS)". Digital surveying and mapping technology and methods have gradually replaced traditional analog surveying and mapping methods and means, and digital surveying and mapping products have replaced paper analog surveying and mapping products. A digital surveying and mapping technology system with "3S" technology as the support and "4D" as the main product form has been basically established, and the leap-forward development from traditional analog surveying and mapping to modern digital surveying and mapping has been realized.
1993, Shenzhen Municipal Bureau of Planning and Land Resources organized relevant units to digitize a large number of white topographic maps with scales of1:1000 and1:2000, and input other surveying and mapping data such as control points at all levels and place names into computers. The database of Shenzhen Basic Geographic Information System (SUPLIS-GIS) is established according to the principle of hierarchical partition. 1996, SUPLIS-GIS was formally built and put into use. Its geographic information includes:1:1000 and1:2000 topographic map data covering the whole city of 2020km2, as well as 6870 DEM data and graphic symbols, control points at all levels, various pipeline data, municipal road planning and design, and various cadastral management data. SUPLIS-GIS is based on Internet technology and network GIS technology, Oracle database stores data, and Arc/info software manages graphic data. It indicates that GIS technology has been widely used in the field of surveying and mapping in Shenzhen, which not only realizes the real-time and remote exchange of spatial data such as topographic maps and cadastres, but also provides services for relevant departments to establish and apply GIS, which provides favorable conditions for the management and update of topographic maps themselves and lays a good foundation and platform for the digitalization of surveying and mapping products.
1995, Shenzhen began to use digital mapping technology to map 1∶ 1000 basic topographic maps, and comprehensively studied and summarized the technical methods, working procedures and quality control of digital mapping in all fields, thus starting the popularization and application of digital mapping technology in Shenzhen. By 1997, digital mapping technology is not only used to revise the basic topographic map of 1∶ 1000, but also widely used in engineering surveying fields such as urban planning and municipal construction, basically eliminating the traditional analog mapping technology and realizing paperless production of mapping. Surveying and mapping products have also changed from paper simulation results to digital surveying and mapping products.
1996, Shenzhen took the lead in transforming the urban control network with GPS technology and established the first urban second-class GPS reference network. After that, the fourth-class GPS network, the first-class urban traverse and the second-class urban traverse covering the whole city were successively surveyed with GPS technology, and special GPS control networks were established for many key projects with GPS technology, such as Shenzhen Metro GPS network and Shenzhen River GPS network. GPS technology has been widely used in Shenzhen. In 2003, the successful establishment of Shenzhen continuous operation reference station brought the application of GPS technology in Shenzhen into a new period.
At present, the surveying and mapping industry in Shenzhen has completely eliminated the traditional analog surveying and mapping technology with digital surveying and mapping technology, achieved a historic leap from traditional analog surveying and mapping to digital surveying and mapping, established a digital surveying and mapping technology system with "3S" technology, computer technology and network communication technology as the core, and improved the digital surveying and mapping production system, digital surveying and mapping product system and service system, technical standards and laws and regulations that are suitable for digital surveying and mapping technology. Digital surveying and mapping technology and digital surveying and mapping products are playing an increasingly important role in the national economic construction, and the digital surveying and mapping system is moving towards the information-based surveying and mapping system.
The third is to develop and build a digital surveying and mapping system with completely independent copyright.
With the development and popularization of digital mapping technology, the focus of research has gradually shifted from technical methods to mapping software. At the beginning of 1996, Shenzhen Survey and Research Institute set up a research group on digital mapping technology to investigate the development status and software application of digital mapping in China. The results show that there is no complete digital mapping system with independent intellectual property rights in domestic surveying and mapping industry, and most surveying and mapping units use it. It must be supported by AutoCAD, which is greatly limited in software upgrade, software maintenance and application. At the same time, it is difficult to exchange data with SUPLIS of Shenzhen Planning Land Information Center.
Developing software with independent intellectual property rights has many advantages over the secondary development of AutoCAD. For example, the source program, data structure and mathematical model are all designed by programmers themselves, which can modify and optimize the system conveniently and quickly, and are completely free from the restrictions of other systems. At the same time, the user interface and all commands are in Chinese environment, so users can operate conveniently and flexibly without mastering English. Besides, according to the data structure requirements of different G IS systems, developers can design more perfect interface software.
In the second half of 1996, the research team successfully developed a DOS version of the CBD digital mapping system with the DOS operating system as the development environment and the object-oriented Borland Pascal 6.0 as the development tool, and then upgraded it several times, from 1.0 to 4.0. 1999 surveying and mapping e system is developed on the basis of CBD system, and Delphi language is selected as the development tool. Because Delphi is actually an upgraded version of Borland Pascal 6.0, it can make full use of the existing algorithms, mathematical models and source programs of CBD system, making the development of Surveying and Mapping E system get twice the result with half the effort. In May 2000, the mapping E system was successfully developed.
Surveying and mapping e system is a purely domestic digital surveying and mapping system with independent intellectual property rights. It is a comprehensive digital mapping system that integrates various large-scale digital mapping, GPS RTK navigation mapping, topographic map vector digitization, earthwork calculation, section measurement, thematic map making, PDA handheld tablet, underground pipe network measurement and other functions. It does not need the support of AutoCAD, but it can realize real-time communication and data exchange with AutoCAD. The system mainly has the following functions and characteristics:
1) Surveying and Mapping E system is a fully functional chinese numerals mapping system with independent intellectual property rights, which can realize real-time communication and data exchange with AutoCAD. The system has friendly interface, intuitive input of symbols and Chinese characters, and convenient and simple earthwork calculation. The data graphic file, which integrates observation values, lines, texts and symbols, is intuitive and convenient, with online object prompt and capture, open command structure, real-time dynamic dragging and real-time dynamic window scaling.
2) Using the technology of automatic generation, disconnection, shearing and curve dynamic modification of codeless contours, contours of any size range can be generated and modified, and attributes and code values can be automatically assigned. External visual input without coding, internal automatic adding technology, preset code blanking technology, establishment and inspection of topological relations, polygon filling and other functions make it easy for operators to realize data interfaces with various G IS systems without memorizing complex element codes.
3) Full map index technology, graphic data separation symbol technology and automatic color separation technology of old and new maps make the revision of digital topographic map intuitive and clear. The description language of outline decoration adopts text mode, which is very convenient to generate and edit and can meet the needs of various conventional and special drawings.
Since the successful development of the system, it has been widely used in the field of surveying and mapping production, such as the dynamic revision of the basic map of Shenzhen, the surveying and mapping of municipal and construction maps of various scales inside and outside the special zone, the calculation of earthwork volume, the measurement of underground pipe network and various thematic cadastral maps.
Since 1996, 996 topographic maps of 1∶ 1000 in Luohu, Nanshan, Yantian, Longgang, Baoan and other places in Shenzhen have been digitally revised by using surveying and mapping e system, and the actual revised area is about 80km2. After 1999, the topographic map of Nanshan District, Baoan District and Longgang District 1∶ 1000 was dynamically tracked and modified, and the actual modified area was 1500 square kilometers. At present, the system continues to be widely used in Shenzhen 65438+. In addition, the surveying and mapping E system is not only used to revise the basic map of 1: 1000, but also widely used in various large-scale urban engineering surveying and mapping, such as 1: 1000, and has successively completed Huanggang Road, the central area, the first-line port of the western passage, and so on. Guangdong L N G Project 1: 500, 1: 1000 digital mapping project, underground pipeline exploration projects in Nanshan District, Longgang District, Luohu District and Baoan District, cadastral survey in Yantian District, private house survey in Xiasha and Xinzhou administrative villages in Futian District, and compilation of multi-purpose cadastral maps in Futian District and Nanshan District.
Fourthly, the application of CHE-CE handheld electronic tablet in topographic map dynamic revision.
Field data collection is one of the important processes of digital mapping, which directly affects the speed and quality of digital mapping. There are two conventional methods: one is total station+small electronic notebook (such as PC-E500). ) sketch on the spot; Second, total station+portable computer electronic tablet. The interface of the first method is character mode, which can not display large graphics, let alone edit graphics, and can only realize single data acquisition. The second method can realize "real-time measurement", but it has some disadvantages, such as high price, short power supply time and not suitable for field work in harsh environment. How to combine the advantages of the two methods is a problem that surveying and mapping technicians are very concerned about.
PDA handheld computer has attracted wide attention in the field of surveying and mapping because of its powerful functions, small size, light weight, strong adaptability to harsh environment in the field, rich communication protocols and hardware support, perfect combination of real-time communication technology with various total stations, and high cost performance. How to make full use of the resource advantages of PDA and develop an electronic tablet based on PDA handheld computer is the dream of scientific and technological personnel in the field of surveying and mapping.
In March, 20001year, Shenzhen Survey and Research Institute successfully developed a mapping electronic tablet CHe-CE system based on PDA, which can be edited in real time during field data collection, achieving the perfect combination of the advantages of portable computer electronic tablet and compact electronic notebook, successfully solving the problems affecting the development of digital mapping technology, and making positive contributions to the development of digital mapping technology.
PDA handheld tablet computer CHeCH is a subsystem of surveying and mapping E system, which is mainly used for field data acquisition. It can automatically record the observation data and convert it into graphics in real time, so that the field data can be visually edited in real time, which realizes the ideal mapping mode of "measuring as soon as possible" and successfully solves the problem that the conventional electronic notebook is separated from sketch recording and office editing, which leads to errors, mistakes and omissions in field data acquisition. CHeCE moves the screen quickly, and the screen moving speed is within 2s; The available memory is large, and it can edit the topographic map of about 3M (equivalent to the AutoCAD data of 6M) and store 6-8 topographic maps of 1: 1000. CHeCE has realized data communication with Topcon, Leica, Nikon, Elta, Pentax, Suojia, Southern Company and Beijing Bofei Company.
CHeCE handheld electronic tablet has been widely used in the dynamic revision of Shenzhen 1∶ 1000 digital topographic map. When using CHECE to modify topographic map, the whole topographic map of about 4M (DXF file is about 8M) can be transferred to PDA, and the changed parts can be deleted, displayed and modified on PDA, and new features and landforms can be directly modified on site. After returning to internal skill, all you need is. Using CHeCE to repair topographic map, the ideal mapping mode of "measuring and using immediately" is truly realized, which not only reduces the occurrence of mistakes, mistakes and leaks, but also improves efficiency and saves costs.
Five, strengthen the archives management of surveying and mapping enterprises
Surveying and mapping enterprise archives are valuable data and achievement databases formed by surveying and mapping enterprises in the process of production, technology, scientific research and management activities. They are not only the labor achievements of the majority of surveying and mapping technicians, but also important resources and precious wealth of surveying and mapping enterprises.
The archives of surveying and mapping enterprises mainly include geodetic survey, photogrammetry and remote sensing, topographic survey, map drawing and map printing, engineering survey, cadastral survey, marine survey, boundary survey, real estate survey, geological survey and survey management.
The establishment and utilization of surveying and mapping enterprise files is an important part of all aspects of enterprise data file management, and it is a means for enterprise files to directly participate in enterprise functional activities and indirectly generate benefits. Making full use of enterprise archives can serve the production, management and scientific research of enterprises, provide paid services for the society, check the quality of collection and archiving, check whether the boundary between preservation and destruction is appropriate, find out the problems existing in enterprise archives management and make targeted corrections and improvements. Therefore, all major geological exploration and surveying and mapping units in Shenzhen regard the establishment and utilization of surveying and mapping files as an important work of quality management.
In recent years, various surveying and mapping industries in Shenzhen have paid attention to actively improving the modernization level of file management, widely used computer technology, network technology and office automation equipment to realize the modernization and automation of file management, and incorporated enterprise files, scientific and technological books and information materials into information construction, giving full play to the role of file resources.