Measurement is also an accurate work. Through the study and practice of surveying, I have formed the basic outline of surveying in my mind. The following is a technical paper on engineering survey compiled by me for you. I hope it will be useful to you.
China's engineering survey technology has made great progress, developed rapidly and achieved remarkable results; However, the development is not balanced, and it can't keep up with the needs of national economic construction, development and social progress. The tasks before us are: vigorously promote the upgrading of engineering survey technical methods and means, actively promote the popularization and application of new technologies, and make full use of control survey technology, topographic mapping technology, field digital mapping with total station, photogrammetry technology and high-resolution remote sensing technology. To develop traditional manual measurement in the direction of electronization, digitalization and automation.
A, total station field digital mapping
Using total station to carry out large-scale digital mapping has realized automation and integration from field data collection and processing to mapping. Many unique large-scale field mapping software have been developed in China, such as EPSW system of Tsinghua Sunway Company, CASS system of south surveying and mapping Company, SCSG system of Guangzhou Case Surveying and Mapping Software Co., Ltd., etc. These systems have been widely used in domestic production units. Paper reference network.
In recent years, the requirement of "high-end total station" put forward by surveying and mapping circles can not only be applied to all kinds of surveying work, but also be used as a "single-person total station", that is, only one person needs to carry out surveying and mapping operations and observation points. In this case, in order to obtain high-quality observation results, new requirements are put forward for the instrument.
Second, the development of photogrammetry technology and its application in large-scale topographic map
It is a common method to use photogrammetry technology package (including aerial photogrammetry and ground photogrammetry) for topographic mapping in the case of large survey area or difficult survey conditions. In recent years, there have been two major breakthroughs in photogrammetry technology. Firstly, digital photogrammetry technology tends to be mature and put into practical application; Secondly, the appearance of GPS makes the field control of photogrammetry simple. They greatly improve the economy and efficiency of photogrammetry, and further enhance its competitiveness and vitality.
Digital photogrammetry, also known as soft copy photogrammetry, fundamentally changes the dependence of photogrammetry on special surveying and mapping instruments with expensive price and complicated optical and mechanical structure, and is a revolution in the field of photogrammetry. Paper reference network. At present, the digital photogrammetry system based on microcomputer can complete a series of operations such as automatic orientation, aerial triangulation, automatic generation of digital terrain model, automatic production of orthophoto map, interactive digital mapping, and acquisition of three-dimensional landscape model with high efficiency and high quality, and its accuracy is equivalent to that of ordinary analytical mapper. Although there are still many defects in the current system, digital photogrammetry has become the mainstream of photogrammetry technology.
Third, the application of high-resolution remote sensing technology in large-scale surveying and mapping.
Remote sensing technology has been successfully applied to resources and environment, disaster monitoring and small-scale mapping. However, due to the low resolution of remote sensing images, it is difficult to be used for large-scale mapping. In recent years, the appearance of new high-resolution satellite remote sensing images provides a new data source for large-scale mapping of cities or regions. IKONOS satellite was successfully launched on September 24th, 1999. It is the first commercial remote sensing satellite in the world to provide high-resolution satellite images. IKONOS digital image with ground resolution of 1m can be provided for making digital orthophoto map, digital ground model and digital line drawing with scale of 1: 10000. QuickBird is a high-resolution commercial remote sensing satellite successfully launched by Digital Globel Company of the United States on 10/2006. The resolution of QuickBird on the ground is 0.6 1m, which can satisfy remote sensing users in more professional and wider application fields and provide users with better and faster remote sensing information source services. On September 18, 2007, Digital Globel announced that it had successfully launched a commercial satellite W: WorldView- 1 and worldview-1with a resolution of 05.m in vandenberg air force base, California, USA, which is the most agile commercial satellite in the world. This is the second commercial satellite successfully launched by Boeing Airlines for Digital-Globel after QuickBird in 2007. This image fully meets the requirements of making 1 1∶0000 scale digital orthophoto map, digital ground model and digital line drawing, and is expected to play an active role in the revision of 15∶000 topographic map.
Four, other topographic mapping technology
Other topographic mapping technologies mainly refer to the digital mapping technology formed by integrating GPS and other sensors on a vehicle and the direct use of GPS mapping technology. Mainly includes:
1 airborne lidar system. Paper reference network. Lidar technology is one of the most revolutionary achievements in the field of photogrammetry and remote sensing in recent decades, and it is the most advanced photogrammetry system to the earth at present. With the support of DGPS and IMU, the laser scanning system processes the measured data through the laser scanner and the distance sensor, displays or stores and outputs the data such as distance and angle through the microcomputer, and matches the data obtained from the distance sensor. After a series of processing by the corresponding software, the surface morphology and three-dimensional coordinate data of the measured object are obtained, so as to carry out various calculations or establish three-dimensional models. The original purpose of this technology is to obtain digital elevation model (DEM) data in difficult areas. In these difficult areas, such as forests and beaches, it is time-consuming and laborious to use conventional photogrammetry methods, and it is difficult to obtain high-precision ground elevation model data. Using airborne lidar system, the ground digital elevation model data can be obtained directly with high efficiency and high precision.
2 (Underwater) Surveying and Mapping System. The system is a mobile surveying and mapping system, which is mainly composed of GPS receiver, automatic sounder, data acquisition software and communication equipment. The accuracy of plane mapping depends on the working mode of GPS and the performance of receiver, while the accuracy of elevation is related to the sounder. It has been widely used in the practice of large-scale underwater topographic survey. The domestic representative products include China Haida Underwater Surveying and Mapping System and South Underwater Surveying and Mapping System. 3(R)TK digital mapping technology. With the further improvement of real-time dynamic differential RTK technology, people put forward the idea of RTK mapping, that is, RTK is used as a total station, and the corresponding supporting software is directly configured to map. This method has a good application prospect in the survey area with few ground objects and thick vegetation coverage.
Verb (abbreviation of verb) conclusion
GPS has become a common means to establish a plane control network. It can be said that the development and application of GPS technology is one of the most brilliant achievements in the field of surveying and mapping this century. With the development and application of differential GPS positioning technology, GPS is not only widely used in high-grade head-end networks and encrypted networks, but also widely used in the determination of map root points and aerial photogrammetry image control points. In many topographic survey projects, photoelectric ranging traverse has always been a basic control survey method. Especially when the total station is used, the low-level map root control can be synchronized with the detailed topographic survey, thus improving the overall work efficiency. Leica's latest total station is the perfect combination of GPS, and it is a high-performance total station (super station instrument) with integrated GPS function. It does not need control points, long traverse lines and rear intersection, but directly uses GPS to determine the three-dimensional coordinates of the point, and then it can be used for surveying and setting out. In the past, the method of geometric leveling has been used in elevation control survey, which is time-consuming and laborious and inefficient. Since the sixties and seventies of this century, with the development of electromagnetic wave ranging technology, electronic ranging trigonometric leveling has emerged. A lot of theoretical research and experimental demonstration work have been done in this field at home and abroad. At present, electronic ranging trigonometric leveling can replace third-class and fourth-class leveling, and most specifications adopt these achievements. Electronic ranging trigonometric leveling is undoubtedly a good supplementary means of geometric leveling. At the same time, with the increasingly extensive application of GPS in plane control survey, the application research of GPS in the field of elevation control survey has also set off an upsurge. Large-scale topographic map mainly refers to the topographic map with the scale of15: 00 ~1:10000. Traditional topographic map generally refers to line drawing, which not only refers to line drawing, but also includes another map with great application potential: image map D(EM, DOM, DTM, etc. At present, digital topographic map package (including digital line drawing, digital orthophoto map, etc. ) has replaced the traditional simulated topographic map and become the main product of topographic survey.
refer to
[1] Zhang Bing, Wang Tiesheng, Gao. Application of GPS Height Fitting Model in Belt Region [J] People's Yellow River, 2009, (07).
, Yuan Ming,, Fan. Research on GPS leveling fitting method in Suzhou [J] Journal of Suzhou University of Science and Technology, 2006, (04).
Xiong Xiaoli, Wu Dijun. Accuracy analysis of GPS height fitting model [J] Railway Survey, 2007, (02).
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