The Central South Survey and Design Institute was established in 1955, and was originally the Central South Branch of the Comprehensive Survey Institute of the Ministry of Construction and Engineering. 197 1 belongs to Hubei Province. It is one of the earliest key survey and design units in China. At present, Zhongnan Survey and Design Institute has Grade A engineering survey (comprehensive), surveying and mapping, consulting and Grade B engineering design qualifications. The institute is composed of various geotechnical technologies, architectural design institutes, Hubei Zhongnan Geotechnical Engineering Co., Ltd. (first-class foundation and foundation engineering construction qualification), Hubei Zhongnan Engineering Construction Supervision Company (first-class qualification) and Hubei Geotechnical Water Conservancy Engineering Technology Development Company (Wuhan Donghu High-tech Enterprise), with branches in Shenzhen, Yichang, Hubei and Xinyang, Henan.
Second, the internship site introduction
Yunfu City is located in the middle and west of Guangdong Province, south of the middle reaches of Xijiang River. It is connected to Zhaoqing and Jiangmen in the east, Yangjiang and Maoming in the south, Wuzhou in Guangxi in the west and Xijiang in the north, facing each other across the river from Fengkai and Deqing counties in Zhaoqing. The urban area is 60 kilometers away from Zhaoqing, 0/60 kilometers away from Guangzhou 177 nautical miles away from Hong Kong/KLOC-0, and the upstream is 60 nautical miles away from Wuzhou, Guangxi. The whole city is within the range of 22.22'-23. 19' north latitude and11.03'-112.3l' east longitude. The total land area of the city is 7779. 1 km2. 1252,000 mu of cultivated land in the whole city in 1998, including paddy field area10120,000 mu and hillside below 25 degrees1304,300 mu. Yunfu City governs Yuncheng District, Yun 'an County, Xinxing County and Yun 'an County, and manages luoding city, including 55 towns 10 streets.
The position of Yunfu City in Guangdong Province
Third, the purpose of production practice
Production practice is an indispensable part of our professional knowledge structure of Surveying and Mapping Engineering, and it is included in the professional teaching plan as an independent project. Its purpose is to enable students to gain perceptual knowledge of basic production through practice, integrate theory with practice and expand their knowledge; At the same time, professional production practice is an important channel to cultivate and train students' professional ability and quality. It is also an important way for students to get in touch with society, understand the industry situation, understand the national conditions, gradually realize the transformation from students to society, cultivate our ability to engage in technical work, and understand the basic methods and skills of enterprise management. Experience the contents and methods of enterprise work. This practical knowledge is a very necessary basis for us to study the follow-up courses and even work in the future.
Fourth, the production practice content
Surveying and mapping of 1: 500 topographic map within 20 square kilometers of Yunfu city. The specific scope is: Muyang Road and Luosha Primary School in the east, Transit Road in the west, Fu Qian Road and Nanshan River in the south, and Gaofeng and Transit Road in the north.
Specifically including:
(1) plane control survey
Terrain control survey includes basic control survey and map root control survey. The basic control points include national geodetic control points at all levels, GPS-C, D and E level points, second, third and fourth level control points in cities and towns, and first and second level control points.
Basic control points should be buried with fixed markers and marked with dots.
Traverse survey and GPS positioning survey can be selected for plane control survey.
The density of map root points should be determined according to the building density and visibility conditions in the survey area, and the principle is to meet the needs of topographic elements mapping. Require no less than 64 points per square kilometer.
(2) elevation control survey:
Fourth-class leveling adopts the midline reading method of one-way observation, and the branch line must be measured back and forth or one-way double-turning point observation. Before observation, the level and leveling rod should be calibrated. The items, methods and requirements of calibration can refer to the national third-and fourth-class leveling standards.
(3) topographic mapping:
Surveying and mapping of 1: 500 digital topographic map in the urban area near Yunfu city and the land use scope approved in 2008. The survey area is east to the intersection of National Highway 324 and Sanmao Railway (Yunbu Village, Silao Town); The north-south length is about 0.5km (100-900m), the east-west length is about 30km, and the survey area is about 15km2.
Technical requirements of verb (abbreviation of verb) project
Technical basis of (1) operation
1. Revision specification of national basic scale topographic map (GB/T 14263-93)
2. Code for Urban Surveying (CJJ 8-99)
3. Global Positioning System Survey Specification (GB/T18314-2001)
4. Digital topographic map series and basic requirements (GB/T18315-2001)
5. Technical Specification for Urban Basic Geographic Information System (CJJ 100-2004)
6. National Third and Fourth Leveling Standards (GB 12898-9 1)
7. Specification for Surveying the Third and Fourth Traverses (CH/T 2007-200 1)-released by the State Bureau of Surveying and Mapping on March 5, 20001.
8. Technical Specification for Global Positioning System Urban Surveying (CJJ73-97)-People's Republic of China (PRC) and the Ministry of Construction issued it on April 25th, 2007 with the number 1997 (JB [1997] No.79).
9. 1: 500, 1: 1000, 1: 2000 topographic map (GB/T 7929- 1995)- State Bureau of Technical Supervision 1995.
10. Technical Specification for Field Digital Mapping (GB/T 149 12-2005)
1 1. The latest topographic map of Yuncheng District of Yunfu City 1: 1 10,000.
12. Plane control achievements of Yunfu City: GPS-D leveling points in Yuncheng District of Yunfu City (with an area of about 79 1.8 square kilometers) and some related GPS-D leveling points around it.
13. Elevation control data of Yunfu City: the third-class leveling results in Yuncheng District of Yunfu City and some related third-class leveling results around this area.
(2) Plane coordinate system, height system and basic vertical spacing.
Provide two sets of coordinate system results respectively:
1. Yunfu independent coordinate system.
2. The plane datum is1980xian coordinate system (hereinafter referred to as 80 coordinate system), and the elevation datum is 1985 national elevation (hereinafter referred to as 85 elevation).
(3) Technical and methodological requirements
1. Plane coordinate system, elevation datum and basic vertical spacing
Plane coordinate system: 80 coordinate system is adopted;
Height system: 85 elevation datum is adopted;
Basic vertical spacing: 0.5m for flat land and hills, and 1.0m for mountains.
2. Drawing scale and drawing method
Drawing method: full analytical digital drawing;
Surveying and mapping scale:1:500;
Map framing: rectangular framing is adopted, the map size is 40cm×50cm, the site is 250 meters long from east to west and 200 meters wide from north to south; With the X coordinate in front and the Y coordinate in the back, the coordinates of contour points in the southwest corner of the map are coded in kilometers. X and Y coordinates are taken as two decimal places, with a short horizontal line connecting them (coordinate numbering method).
(4) Precision requirements
The accuracy of control points must conform to the national standards such as "Code for Urban Surveying", "Code for Global Positioning System (GPS) Surveying" and "Code for National Third and Fourth Leveling". The accuracy of topographic map must conform to the national standards such as "Cadastral Survey Specification" and "Detailed Rules for the Implementation of Urban Cadastral Survey in Guangdong Province".
In order to meet the needs of land management and real estate management in our district, the plane survey accuracy of the detailed points related to the determination of ownership, such as houses, fences, kerbs and roads, should meet the following table:
Accuracy requirements of plane measurement
The application range of the error of the root point of a class relative to the point position of an adjacent graph
1 ≤5cm General corner, fence and other obvious features.
2 ≤7.5cm Hidden corners, fences, curbs and road features of the old city.
(5) Topographic map data storage
Building surface: Building construction is required, and the structure, floor and building number in the building surface attribute table should be consistent with the drawing information. Property pages with community names must be filled with community names.
Pavement: All levels of named roads, urban streets and tunnels should be built, and the intersection of pavements should meet the topological relationship, that is, the points on the sides are completely coincident.
Road centerline: All roads, urban streets and roadways with names shall be drawn with road centerline (drawn in the office without field excavation points), and the road centerline shall be filled with "road name" and "road width" (average width). All roads and one line are required, and roads are allowed to cross.
Place name landmarks: Place names include township (street) names and village (residence) names. It is required that the place name information in the survey area is complete and accurate. At the same time of map labeling, it is required to fill in the attribute table of place name labeling points with "place names" consistent with the map.
Company name marking point: the company name includes the names of institutions, enterprises, institutions, companies, communities, etc. When marking drawings, it is required to fill in the "company name" consistent with the drawings in the attribute table of company name marking points.
Water surface: classify water bodies and construct water surface, and fill in the "water body name" consistent with the drawing in the attribute information table.
(six) submit the results of the material
1. Instrument inspection data or instrument inspection certificate;
2. Control point record;
3. Observation manual;
4. Adjustment calculation data and precision statistics;
5. Control network spread point network diagram (80 coordinate system), plane control joint survey diagram and leveling road map;
6. 1: 500 topographic map: block map and sheet map.
Sixth, internship experience
The 44-day summer production internship has made me a surveying and mapping student who is about to enter the society gain a lot. Whether it is work experience or life lessons, I think it will be improved for us. We have been making progress from plane control survey to step survey. Compared with the previous classroom practice, the time is more concentrated, the content is wider and the procedure is more systematic. It is to deepen the further understanding, mastery and comprehensive application of book knowledge on the basis of measuring actual production. It is an important teaching link to cultivate students' ability to integrate theory with practice, work independently, comprehensively analyze and solve problems, and organize and manage, and it is also a concrete, vivid and managed teaching link. It has more important significance in imparting knowledge, developing intelligence and cultivating comprehensive quality.
First, teamwork. This production practice also made me really realize that surveying and mapping is a team work. Indeed, if a project wants to be successfully completed, it is far from enough to rely on one person's strength and conception, and it is impossible to complete the task well. Only the cooperation and unity of all members of the team can complete the task with good quality and quantity. As the saying goes, "Two heads are better than one." In addition, this production practice has also cultivated our ability of division of labor and cooperation, enhanced the feelings between students and deepened friendship. It is inevitable that we will encounter some rough things in the internship process, which will make everyone unhappy, but we can communicate in time, forget yesterday's unhappiness and welcome the new sunrise.
The second is the ability to work. Through this internship, I found that as an undergraduate majoring in surveying and mapping, the basic knowledge is still not solid, which is highlighted in the process of work. I will explain some individual details.
1. Plane control measurement: The plane control measurement has a front and rear prism. Because of the high precision of control measurement, it is a test for students who oppose prism. The horizontal bubble is in the middle and requires a fairly high level. However, perhaps the vial of the vertical prism is centered, but it is not allowed for the middle rod itself. Therefore, we aim at the bottom of the centering rod first, then fix the horizontal angle and move our eyes to the prism lens, thus greatly improving the control accuracy. Of course, this method is still applicable to the orientation of graph root control and step measurement.
2. Sketch scale: At the beginning of sketching, the scale was too small, which made many small parts difficult to identify, such as manhole covers and telephone poles. Therefore, when drawing electronic drawings, the whole sketch is a mess, which requires us to have a moderate scale when drawing sketches. Through this production practice, my personal experience is to draw a sketch according to the field of vision of the stands and draw an eagle eye map next to the next page or some special places.
3. Elevation point: This point is not a simple elevation point, but a surveying and mapping standard or an industry standard. In the tender of Yunfu Land and Resources Bureau, it is clearly stipulated in the "Elevation Notes" of "Topographic Element Survey" that "this survey will note elevation points according to the required density (generally not less than 5 annotation points per square)", but until a few days ago, we have been making up the elevation points, just because we have not carefully studied the big standards, which is a lesson.
Of course, there are still many shortcomings, such as adjustment, slow mapping in the field, slow mapping in the office, and no fixed format for data storage, which need our serious reflection.
Here, I want to thank Mr. Zhang, who has been with us for so many days, and Mr. Sun, who has taught us knowledge.