This standard specifies the quality characteristics of digital line-drawn topographic maps and digital elevation model products and the requirements they should meet. This standard applies to the inspection, acceptance and quality assessment of digital line-drawn topographic maps and digital elevation model products in digital surveying and mapping and the construction of basic geographic information databases. GB/T 17941.1-2000 Quality requirements for digital surveying and mapping products Part 1: Quality requirements for digital line-drawn topographic maps and digital elevation models GB/T17941.1-2000 Standard download decompression password: www.bzxz.net
This standard specifies the quality characteristics of digital line-drawn topographic maps and digital elevation model products and the requirements they should meet. This standard applies to the inspection, acceptance and quality assessment of digital line-drawn topographic maps and digital elevation model products in digital surveying and mapping and the construction of basic geographic information databases.

GB/T17941.1—2000
This standard is formulated for the first time in China. This standard is formulated in response to the need for quality control of digital line topographic maps and digital elevation models in digital surveying and mapping and the construction of basic geographic information databases, based on the current technical level. This standard is a supplement to CH1003--1995 "Surveying and Mapping Product Quality Assessment Standards" and CH1002-1995 "Surveying and Mapping Product Inspection and Acceptance Regulations". This standard is proposed and managed by the State Administration of Surveying, Mapping and Geoinformation. The drafting unit of this standard is: Surveying and Mapping Standardization Research Institute of the State Administration of Surveying, Mapping and Geoinformation. The main drafters of this standard are: Wang Zhanhong, Ma Xiaoping, Cheng Yanhui, Wu Xiaoli. 505
National Standard of the People's Republic of China
Quality requirements for digital products of surveying and mapping-Part 1 : Quality requirement for digital line topographic map,digital elevation model
1 Scope
GB/T 17941. 1--2000
This standard specifies the quality characteristics of digital line topographic map and digital elevation model products and the requirements they should meet. This standard is applicable to the inspection, acceptance and quality assessment of digital line topographic map and digital elevation model products in digital surveying and mapping and the construction of basic geographic information database.
2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. GB14804--19931:500, 1:1000.1:2000 Classification and code of topographic map elements GB/T15660-19951:5000, 1:100001:25000, 1:50000, 1:100000 Classification and code of topographic map elements GB/T13923-1992 Classification and code of land basic information data 3 General Principles
3.1 The quality requirements of digital surveying and mapping products are described by the requirements for several quality characteristics according to the different types of products. 3.2 Data description is an important quality characteristic of digital surveying and mapping products. Digital surveying and mapping products should contain data description. Data description can be stored in the file header of the product data file or in a separate file. The data description file should be a text file. The layout format of the content can be determined by yourself, but it must contain the data items specified in 4.1 and 5.1. For data items that are not suitable for a certain product, only the data item name can be listed without filling in the specific value.
4 Quality requirements for digital line topographic maps
The quality requirements for digital line topographic maps are described by the requirements for product data description, mathematical basis, data classification code, position accuracy, attribute accuracy, logical consistency, completeness and other quality characteristics. 4.1 Data description
The data description of digital line topographic maps should include the contents shown in Table 1. Approved by the State Administration of Quality and Technical Supervision on January 3, 2000 506
Implemented on August 1, 2000
1. Product name, range description
2. Storage description
3. Mathematical basis description
4. Standard description
5. Data source and data collection method description
6. Data stratification description
7. Product production description
8. Product inspection description
9. Product ownership description
4.2 Mathematical basis
GB/T 17941. 1—2000
Table 1 Data description of digital line topographic map Content 1. Product name
3. Product coverage
1. Database name or file name
2. Storage format and/or brief instructions for use
1. Ellipsoid
4. Height datum
2. Projection
2. Map name and map number
4. Scale
3. Plane coordinate system
5. Contour interval
1. Name and number of topographic map pattern
3. Name and number of topographic map element classification and code standard1. Acquisition by photogrammetry method
2. Digitization of topographic map
3. Field measurement
1 Layer name
1. Production unit
2. Production date
1. Acceptance unit
2. Accuracy and grade
3. Acceptance date
1. Ownership unit
1. Aerial (aerospace) photographs
2. Name and number of surveying or compiling specifications
4. Others
1. Aerial scale
2. Aerial altitude
3. Focal length of aerial camera
5. Aerial camera model
6. 7. Aerial photography date
8. Aerial photography unit
8. Sensor type
9. Satellite image resolution
10. Segment selection
11. Data receiving time
2. Photogrammetry equipment and software
1. Digitized original image
2. Mathematical equipment and software
1. Surveying equipment and software
1. Original image scale
2. Production unit
3. Production date
The mathematical basis of the national basic scale series of digital line topographic maps should be implemented in accordance with the mapping specifications and compilation specifications of the corresponding scale. 4.3 Data classification and code
Data classification and code of national basic scale digital line topographic map shall be implemented in accordance with GB14804, GB/T15660 and GB/T13923 according to different scales. Supplementary elements and codes shall be explained in the data description notes. 4.4 Position accuracy of digital line topographic map data 507
4.4.1 Plane accuracy
GB/T 17941.1-2000
a) The coordinate values ​​of outline points, intersection points of kilometer grid or longitude and latitude grid, control points, etc. in digital line topographic map shall conform to the theoretical values ​​and known coordinate values.
b) The mean error of the position of the topographic point to the adjacent control point and the mean error of the distance between adjacent ground object points of the digital line topographic map measured data (data collected by ground measurement and photogrammetry) shall not exceed the provisions of the corresponding scale mapping specifications. c) For digital line topographic maps collected by map digitization, the displacement deviation of point targets shall not exceed ±0.1XMm (M is the denominator of the scale, the same below), and the displacement deviation of linear targets shall not exceed ±0.2×Mm. 4.4.2 Elevation accuracy
a) For digital line topographic maps collected by measured data, the elevation error of elevation annotation points and contour lines to adjacent elevation control points shall not exceed the corresponding scale mapping specifications.
b) For digital line topographic maps collected by map digitization, the elevation values ​​of elevation points and contour lines should be correct, and the two should not produce geographical adaptability conflicts.
4.4.3 Shape fidelity
The graphics of each element can correctly reflect the morphological characteristics of the actual objects without deformation and distortion. 4.4.4 Edge connection accuracy
Adjacent map sheets should be naturally connected. Line elements and surface elements should be connected in both graphic geometric position and attribute. When the edges cannot be naturally connected due to mapping at different times, it is allowed to remain unconnected, but the problem should be recorded and the connection can be made when reliable data is available.
4.5 Accuracy of attribute data of digital line topographic map 4.5.1 Correctness of attribute data
The various attribute data describing the characteristics of each terrain element must be correct. 4.5.2 Completeness of attribute data
The attribute item types describing the characteristics of each terrain element should be complete and should comply with the classification and code of the corresponding scale topographic map elements or the respective attribute codes specified in the technical documents, and no omissions should be made. 4.6 Logical consistency of digital line topographic map data The relative positions of each element should be correct and can correctly reflect the distribution characteristics and density characteristics of each element. The line segments intersect, there is no hanging or overshoot phenomenon, the surface area must be closed, the auxiliary lines should be correct, and the common boundary line or the same target can only be digitized once when it has two or more types of features and copied to the corresponding data layer. For directional elements, the digitization direction must be correct, and the objects that need to be connected should remain connected. The relationship between the data layers should be handled correctly.
4.7 Completeness of digital line topographic map elements 4.7.1 Completeness of elements
All elements in digital line topographic maps must be correct and complete, without omissions or duplications. 4.7.2 Correctness of data stratification
All requirements should be stratified according to the relevant technical design documents. Data stratification should be correct, without duplication or missing layers. 4.7.3 Completeness and correctness of notes
All name notes and explanation notes should be correct, with clear instructions and no errors or omissions. 4.8 Graphic quality of digital line topographic maps
When digital line topographic maps are simulated, their lines should be smooth, natural, clear, without jitter, repetition, etc. The symbol representation specifications should comply with the regulations of the corresponding scale topographic map format. Notes should try to avoid overlapping features, and their font, font size, number of words, font direction, units, etc. should generally comply with the regulations of the corresponding scale topographic map format. The specified intervals should be maintained between symbols to achieve clarity and readability. 5 Quality requirements for digital elevation models
The quality requirements for digital elevation models are described by the requirements for the two quality characteristics of the product, data description and data accuracy. 508
5.1 Data description
GB/T 17941. 1--2000
The data description of the digital elevation model should include the contents shown in Table 2. Table 2 Contents of digital elevation model data description
1. Product name and category description
2. Storage description
3. Mathematical basis description
4. Regular grid description
5. Data source and data collection method description
6. Data interpolation description
7. Product production description
8. Product inspection description
9. Product ownership description
1. Product name
2. Scale
3. Product coverage
1. Database name or file name
2. Storage format and/or brief instructions for use1. Ellipsoid
4. Elevation datum
3. Plane coordinate system
1. Grid unit positioning point position (upper left, lower left, upper right, lower right, center)2. Starting grid unit coordinates
3. Grid unit spacing
4. Total number of grid rows and columns
1. Photogrammetry collection
2. Topographic map collection
3. Field measurement
1. Data interpolation method
1. Production unit
2. Production date
1. Acceptance unit
2. Accuracy and level
3. Acceptance date
1. Affiliated unit
1. Aerial (aerospace) photographs
1. Aerial scale
2. Aerial altitude
3. Focal length of aerial camera
5. Model of aerial camera
6. Date of aerial photography
7. Aerial unit
8. Sensor type
9. Satellite image resolution
10. Band selection
11. Data receiving time
2. Photogrammetry equipment and software
1. Digital map
2. Digital equipment and software
1. Measurement equipment and software
1. Scale of original image
2. Production unit
3. Production date
5.2 Data accuracy
GB/T17941.1-—2000
The data accuracy requirements for digital elevation model products include requirements for grid cell spacing, elevation accuracy and edge accuracy. 5.2.1 Grid cell spacing
The grid cell spacing of the digital elevation model shall be implemented in accordance with the provisions of Table 3. One of the two appropriate sizes can be selected as needed. For digital elevation models that do not belong to the basic scale series, appropriate adjustments can be made according to Table 3. Table 3 Grid spacing of digital elevation model
Scale
1:1000000
1:500000
11250000
1100000
1-50000
125000
1+10000
1:5000bZxz.net
1:2000
5.2.2 Elevation accuracy
Grid unit spacing, m
1000/500
500/250
250/100
100/50
12.5/6.25
Grid unit spacing, (\)
1.25/0.625
5.2.2.1 The mean error of grid point elevation of digital elevation models generated by photogrammetry and field measurement should not be greater than the mean error of contour line elevation specified in the mapping or compilation specifications for topographic maps of corresponding scale. 5.2.2.2 The mean error of grid point elevation of digital elevation models generated by topographic map digitization should not be greater than 2/3 of the contour interval of topographic maps of corresponding scale.
5.2.3 Edge sugar content
There should be no loopholes in the adjacent digital elevation models. The plane coordinates of the grid points in adjacent rows (columns) between two digital elevation models should be continuous and meet the grid spacing requirements. The elevation should meet the overall characteristics of terrain continuity. Even if there is a jump, it should meet the landform characteristics. 5.2.4 Twice the error in elevation is stipulated as the maximum limit difference of grid point elevation. 5101 Grid cell spacing
The grid cell spacing of the digital elevation model shall be implemented as specified in Table 3. One of the two appropriate sizes can be selected according to the needs. For digital elevation models that do not belong to the basic scale series, appropriate adjustments can be made according to Table 3. Table 3 Grid spacing of digital elevation model
Scale
1:1000000
1:500000
11250000
1100000
1-50000
125000
1+10000
1:5000
1:2000
5.2.2 Elevation accuracy
Grid unit spacing, m
1000/500
500/250
250/100
100/50
12.5/6.25
Grid unit spacing, (\)
1.25/0.625
5.2.2.1 The mean error of grid point elevation of digital elevation models generated by photogrammetry and field measurement should not be greater than the mean error of contour line elevation specified in the mapping or compilation specifications for topographic maps of corresponding scale. 5.2.2.2 The mean error of grid point elevation of digital elevation models generated by topographic map digitization should not be greater than 2/3 of the contour interval of topographic maps of corresponding scale.
5.2.3 Edge sugar content
There should be no loopholes in the adjacent digital elevation models. The plane coordinates of the grid points in adjacent rows (columns) between two digital elevation models should be continuous and meet the grid spacing requirements. The elevation should meet the overall characteristics of terrain continuity. Even if there is a jump, it should meet the landform characteristics. 5.2.4 Twice the error in elevation is stipulated as the maximum limit difference of grid point elevation. 5101 Grid cell spacing
The grid cell spacing of the digital elevation model shall be implemented as specified in Table 3. One of the two appropriate sizes can be selected according to the needs. For digital elevation models that do not belong to the basic scale series, appropriate adjustments can be made according to Table 3. Table 3 Grid spacing of digital elevation model
Scale
1:1000000
1:500000
11250000
1100000
1-50000
125000
1+10000
1:5000
1:2000
5.2.2 Elevation accuracy
Grid unit spacing, m
1000/500
500/250
250/100
100/50
12.5/6.25
Grid unit spacing, (\)
1.25/0.625
5.2.2.1 The mean error of grid point elevation of digital elevation models generated by photogrammetry and field measurement should not be greater than the mean error of contour line elevation specified in the mapping or compilation specifications for topographic maps of corresponding scale. 5.2.2.2 The mean error of grid point elevation of digital elevation models generated by topographic map digitization should not be greater than 2/3 of the contour interval of topographic maps of corresponding scale.
5.2.3 Edge sugar content
There should be no loopholes in the adjacent digital elevation models. The plane coordinates of the grid points in adjacent rows (columns) between two digital elevation models should be continuous and meet the grid spacing requirements. The elevation should meet the overall characteristics of terrain continuity. Even if there is a jump, it should meet the landform characteristics. 5.2.4 Twice the error in elevation is stipulated as the maximum limit difference of grid point elevation. 510
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