In order to meet the needs of national economic construction, national defense construction and social development, strengthen China's geodetic work and standardize geodetic behavior, this standard is formulated in accordance with the "Surveying and Mapping Law of the People's Republic of China". This standard specifies the basic technical indicators and technical requirements for establishing and maintaining geodetic control networks, elevation control networks and gravity control networks, and determining quasi-geoids. It is applicable to geodetic activities conducted in the territory of the People's Republic of China and other sea areas under its jurisdiction. This standard clarifies the basic technical provisions for geodetic surveying in China and is the main basis for formulating and revising relevant specific technical standards for geodetic surveying. For the specific technical methods and technical requirements for establishing and maintaining China's geodetic control networks, elevation control networks and gravity control networks, corresponding technical standards will be formulated separately to guide and standardize surveying work. GB 22021-2008 Basic Technical Provisions for National Geodetic Surveying GB22021-2008 Standard Download Decompression Password: www.bzxz.net
In order to meet the needs of national economic construction, national defense construction and social development, strengthen China's geodetic work and standardize geodetic behavior, this standard is formulated in accordance with the "Surveying and Mapping Law of the People's Republic of China". This standard specifies the basic technical indicators and technical requirements for establishing and maintaining geodetic control networks, elevation control networks and gravity control networks, and determining quasi-geoids. It is applicable to geodetic surveying activities conducted in the territory of the People's Republic of China and other sea areas under its jurisdiction. This standard clarifies the basic technical provisions for geodetic surveying in my country and is the main basis for formulating and revising relevant specific technical standards for geodetic surveying. For the specific technical methods and technical requirements for establishing and maintaining my country's geodetic control networks, elevation control networks and gravity control networks, corresponding technical standards will be formulated separately to guide and standardize surveying work.


Preface………………………………………………………………………………………………………… Ⅰ
Introduction……………………………………………………………………………………………… Ⅱ
1 Scope……………………………………………………………………………………………… １
2 Terms and definitions…………………………………………………………………… １
3 General provisions……………………………………………………………………………… １
4 Geodetic datum and geodetic control network……………… ２
4.1 Geodetic datum…………………………………………………………………… ２
4.2
５.1 Elevation datum …………………………………………………………………………………… ３
５.2 Elevation
control network………………………………………………………………… ３ ５.3
Quasi-geoid…………………………………………………………………………… ４ ６ Gravity datum
and gravity measurement control network…………………… ４
６.1 Gravity datum……………………………………………………………………………… ４
６.2 Gravity measurement control network……………………………………………………………………………… ４
６．3 Encrypted gravity measurement………………………………………………………………………… ５
７ Depth datum…………………………………………………………………………………… ５
Appendix A (Normative Appendix) Definition and reference ellipsoid constants of the 2000 National Geodetic Coordinate System… ６
Appendix B (Normative Appendix) Definition and parameters of the 1985 National Height Datum… ７

ICS 07.040
National Standard of the People's Republic of China
GB22021-2008
Basie specifications for national geodesy
Release date: 2008-06-20
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Administration of Standardization of the People's Republic of China
Implemented on 2008-12-01
GB 220212008
Terms and Definitions
4 Geodetic Datum and Geodetic Control Network
4.1 Geodetic Datum
4.2 Geodetic Control Network
Elevation Datum and Elevation Control Network
Elevation Datum
Elevation Control Network
Quasi-geoid
Gravity Datum
Gravity Measurement Control Network
Encrypted Gravity Measurement
Depth Datum
Appendix A (Standard Appendix)
2000 National Geodetic Standard System Definition and Reference Standard Appendix B (Standard Appendix) 1985 National Elevation Datum Definition Yihe Zero Number Chinese Standard Quality Base
All technical contents of this standard are mandatory. This standard is proposed by the State Administration of Surveying, Mapping and Geoinformation.
This standard is under the jurisdiction of the National Technical Committee for Geographic Information Standardization. Appendix A and Appendix B of this standard are normative appendices GB220212008
Drafting units of this standard: Surveying and Mapping Standardization Institute of the State Administration of Surveying, Mapping and Geoinformation·National Basic Geographic Information Center·First Geodetic Surveying and Mapping Bureau of the State Administration of Surveying, Mapping and Geoinformation, Chinese Academy of Surveying and Mapping,
Main drafters of this standard are Xiao Xuenianxing, Guo Dianli, Zhang Yanping, Zhang Chuanshengqiang
Chinese Standard Quality Base
GB220212008
In order to meet the national economic construction, the State In order to meet the needs of national defense construction and social development, strengthen my country's geodetic work and standardize geodetic behavior. This standard is formulated in accordance with the Surveying and Mapping Law of the People's Republic of China. The geodetic survey referred to in this standard refers to the surveying activities to determine the position, shape of the earth, gravity field and its changes over time and space for the purpose of establishing and maintaining surveying and mapping benchmarks and surveying and mapping system surfaces. Its tasks are to establish and maintain geodetic benchmarks, elevation benchmarks, depth benchmarks and gravity benchmarks, determine and refine the quasi-geoid and earth gravity field model. This standard clarifies the basic technical provisions for geodetic surveying in my country, and is the main basis for formulating and revising relevant geodetic specific technical standards. The specific technical methods and technical requirements for establishing and maintaining my country's geodetic control network, elevation control network and force control network will be separately 1 Scope
Basic Technical Provisions for National Geodetic Survey
GB220212008
This standard specifies the basic technical indicators and technical requirements for establishing and maintaining geodetic control networks, elevation control networks and gravity control networks, and determining quasi-geoids, so as to achieve a unified national geodetic datum, elevation datum and its corresponding depth datum and gravity datum. This standard applies to geodetic survey activities conducted in the territory of the People's Republic of China and other sea areas under its jurisdiction. Free reading
2 Terms and definitions
The following terms and definitions apply to this standard
Geodetic coordinate system geodetic 2.2
geodetic coordinate framebzxZ.net
gcodetic coordinate referenceTrameThe specific implementation of the geodetic coordinate system, which is reflected by a set of specific quantitative markers fixed on the surface of the earth and their fixation and other parameters in multiple systems
geodetiedatim
geodetic datum
consists of the geodetic coordinate system and the geodetic quantitative marker framework. 2.4
satellite positioning continuously operating reference stationsAn observation system composed of a satellite positioning system receiver (including antenna), computer meteorological equipment, communication equipment and power supply equipment, observation towers, etc. It continuously tracks observation satellite signals for a long time and transmits the observation data to the data center through a data communication network in a timely, real-time or according to the requirements of the data center. It can provide real-time fast connection or post-event payment services either stand-alone or networked. Standard publication
Densified gravity measurement density gravity measurement is the gravity measurement carried out on the basis of gravity control points at all levels in the relevant areas for various scientific purposes by adding certain gravity points. 3 General provisions
3.1 Under the premise of complying with this standard, when engaging in geodetic surveying and corresponding surveying activities, the operation process shall be based on the geodetic technical specifications and guiding technical documents stipulated by the state. 3.2 When using corner measurement, astronomical measurement and other methods for control measurement, the technical requirements and operation process shall be based on the geodetic technical specifications and guiding technical documents stipulated by the state. 3.3 Geodetic surveying adopts mean error as the technical indicator of accuracy, and 2 times the mean error as the limit error. 34 Only instruments used in geodetic surveying can be used after passing the legal metrological standards. 3.5 Geodetic control points shall be equipped with fixed benchmarks or signs, and their structure and establishment method shall be based on the principles of stability and suitability for permanent preservation.
GB 220212008
4 Geodetic datum and geodetic control network
4.1 Geodetic datum
4.11 Geodetic datum consists of geodetic coordinate system and geodetic coordinate frame: The country adopts the geocentric coordinate system as the national unified geodetic coordinate system. The geodetic coordinate frame is specifically embodied by the geodetic control network that realizes the geodetic coordinate system. The national geodetic standard system is used in the 1954 Beijing coordinate system and the 1980 Xi'an coordinate system. 4.13 The coordinates of the geodetic control points shall be expressed in geodetic coordinates (geodetic longitude B, geodetic latitude L and geodetic height H) or spatial rectangular coordinates (XY, 2).
4.2 Geodetic control network
4.21 General provisions
4.21 Geodetic control networks are divided into four levels according to their accuracy and purpose. 4.21.2 Geodetic control networks can be deployed at different levels when the accuracy and other technical requirements are met. 4.21.3 Before the official completion of the results of the astronomical geodetic control network, the geodetic control network deployment in land-based national disaster areas and islands (constructions) far away from the continent can be maintained according to the premise of ensuring accuracy. When the national conditions are limited and it is impossible to meet the requirements of this standard, 421.4|| tt||Approved by the administrative department at the provincial level, its technical indicators can be appropriately adjusted according to actual conditions. 4.22 Geodetic control network
4.22 National first-class geodetic control network
4.221 The national first-class geodetic control network is composed of satellite positioning continuous operation base stations. It is the main product of the national geodetic benchmark. In order to achieve the national maintenance of my country's three-dimensional dynamic geodetic calibration system to ensure the accuracy and timeliness of the three-dimensional geocentric coordinates of the geodetic control network points. 4.2212
The annual average deviation of each component of the geocentric coordinates of the satellite positioning continuous operation base station of the national first-class geodetic control network should not be greater than ±0.5mm+relative accuracy should not be less than 1×10# coordinate The error in the annual biochemical rate is not more than 2m/s in the horizontal direction and not more than 3mm in the vertical direction.
4.22.1.3 The national annual geodetic control network points should be evenly distributed as follows: # In my country, under sufficient conditions, they should be arranged near the national first-class leveling routes and at the nodes of the national first-class leveling network. 4.22.1.4 Satellite positioning continuous operation reference stations established by local governments or departments, which meet the national unified station construction technical standards and the technical indicators specified in this standard, can be included in the national first-class geodetic control network after certification. 4.22.2 National second-class geodetic control network
4.22.21 The purpose of the national second-class geodetic control network is to achieve the national first-class leveling. The large-scale stability monitoring of the network is combined with precise leveling, gravity measurement and other technologies to refine the quasi-geoid of my country, providing starting data for the establishment of the third-level and local geodetic control networks.
4.22.2.2 The mean error of the horizontal component of the baseline between adjacent points of the national second-level geodetic control network should not be greater than ±5mm, and the mean error of the vertical component should not be greater than ±10mm: the relative accuracy of each control point should not be less than 1×10-, and the average distance between the points should not exceed 50km4.22.23 The points of the national second-level geodetic control network should be evenly distributed, taking into account the application services and the large-scale stability monitoring of the national first and second-level leveling networks. 4.22.24: The re-survey cycle of the national second-class geodetic control network is 5 years, and the execution time of each survey should not exceed 2 years. 4.22.3 Third-class geodetic control network
4.22.3.1 The purpose of the third-class geodetic control network survey is to establish and maintain a national (or regional) geodetic control network to meet the basic needs of national basic scale mapping. Combined with leveling and gravity measurement technology, refine the provincial or regional quasi-geoid. 4.22.3.2 The mean error of the horizontal component of the baseline between adjacent points of the third-class geodetic control network should not be greater than ±10 plus ugly, and the mean error of the vertical component should not be greater than ±20mm+. The relative accuracy of each control point should not be less than 1×10-, and the average distance between points should not exceed 20km. 2
GB22021-2008
4.22.3.3 The layout of the third-class geodetic control points should be consistent with the provincial basic surveying and mapping services, the existing technical application level and the quasi-geoid refinement standards. Wells should be laid out on the third and fourth-class leveling lines as much as possible. 4.22.3.4 The third-order geodetic control network should be re-surveyed or updated as needed 4.22.4 The fourth-order geodetic control network
4.22.4.1 The fourth-order geodetic control network is an encryption of the third-order geodetic control network. 4.22.4.2 The mean error of the horizontal component of the baseline between adjacent points of the fourth-order geodetic control network should not be greater than 20 mm, and the mean error of the vertical component should not be greater than 40 mm+. The relative accuracy of each control point should not be less than 1×10-, and the average distance between points should not exceed 5 km. 4.22.4.3 The fourth-order geodetic control network should be re-surveyed or updated as needed 5 Elevation benchmark and elevation control network
5.1 Elevation Datum
The national elevation system adopts the normal height system. The national elevation datum 185 defines the average sea level of the Yellow Sea as the unified elevation starting surface for the whole country. The national elevation datum is further embodied by the elevation control network and the quasi-geoid. The definition and gold number of the national elevation datum of 185 are shown in Appendix B.
5.2 Elevation Control Network
General Provisions
5.211 The accuracy of leveling techniques is divided into one, two, three and four grades. The elevation control network is mainly laid out by leveling. The leveling points are divided into one, two, three and four grades. The distance between leveling points is, #m- 8k also, in areas where traffic is difficult, it may be appropriately relaxed with approval.
5.21.2 When the national elevation datum transmission and elevation control network layout in areas far away from large areas cannot meet the requirements of this standard due to system limitations, its technical indicators may be appropriately relaxed with approval. 5.22 National first-class leveling network
5.22.1 The national first-class leveling is the backbone of the national commercial engineering control network. Its main purpose is to achieve high-precision transmission of the national commercial engineering datum. 5.22.2 The layout of the national first-class leveling network should fully take into account the local construction background and choose the most appropriate route. The national first-class leveling route should be closed into a ring and form a network. The same length of the ring In the eastern region of my country, it should not exceed 600km, and in the western region it should not exceed 2000km. 5.22.3 The accidental mean error of each kilometer calculated by the round-trip measurement error of the national first-class leveling should not be more than 0.45m, and the total mean error of each kilometer calculated by the loop closure error should not be less than ±1.0mm. 5.22.4 The national first-class leveling network is surveyed once every 15 years, and the survey execution time shall not exceed 5 years. 5.23 National second-class leveling network 5.2.3.1 The national second-class leveling network is an encryption of the national first-class leveling network, and is arranged in a contiguous route or ring shape within the national first-class leveling network. The circumference of the national second-class leveling loop line shall not exceed 750km in plain and hilly areas, and may be appropriately increased in mountainous and difficult-to-reach areas upon approval. 5.23.2 The accidental mean error per kilometer calculated by the round-trip measurement discrepancy value of the national first-class leveling survey shall not exceed ±10mm, and the total mean error per kilometer calculated by the loop closure error shall not exceed ±2.0mm. 5.23.3 The national second-class leveling network shall be re-surveyed as needed, and the re-survey cycle shall not exceed 20 years. 5.24 Third-class and fourth-class leveling networks
5.24.1 The third-class and fourth-class leveling networks are further densifications of the national first-class and second-class leveling networks. The third-class leveling routes shall generally form a ring, or be closed between high-class leveling routes, and the fourth-class leveling treads shall be closed between high-class leveling treads or form branches. 5.24.2 The accidental mean error per kilometer calculated by the round-trip measurement discrepancy value for third and fourth order leveling shall not be greater than ±3.0 mm and ±5.0 mm respectively, and the total mean error per kilometer calculated by the loop closure error shall not be greater than ±6.0 mm and ±10.0 mm respectively. 5.24.3 The third and fourth order leveling shall be surveyed, re-surveyed or updated as needed8
GB220212008
5.3 Quasi-geoid
5.3.1 General provisions
5.3.1.1 Under the condition that the application requirements are met, the quasi-geoid model combined with satellite positioning technology can be used as a way to determine the elevation.
5.3.1.2 The quasi-geoid is represented by the average elevation anomaly of a certain resolution of the grid. Its accuracy and resolution are represented by the average mean error of the elevation anomaly of the grid average elevation anomaly relative to the elevation anomaly control points in the region and its grid spacing. 5.3.1.3 The accuracy of the quasi-geoid should be checked and evaluated by field measurement methods of corresponding accuracy. 531.4 The quasi-geoid in my country is divided into national quasi-geoid, provincial instrumental geoid and urban quasi-geoid according to its scope, accuracy and purpose.
5.3.2 National quasi-geoid
5.3.2.1 The resolution of the national quasi-geoid shall not be less than 1515 and its accuracy: for flat land and hilly land, it shall not be less than ±0.3m+/- and for high mountainous land, it shall not be less than ±0.6m+/-. 5.3.2.2 The coordinate and elevation accuracy of the elevation control points of the national quasi-geoid shall not be less than that of the national geodetic control points and the national second-class leveling points. 5.3.3 Provincial geoid 5.3.3. The resolution of the provincial geoid shall not be less than 5×5 and its accuracy: for flat land and hilly land, it shall not be less than ±0.1m+/-. The height of the mountain is not less than 0.48m
5.3.3.2 The accuracy of the height anomaly difference of the adjacent elevation anomaly control points of each level of quasi-geoid shall not be less than the geotechnical standard on flat land and terrain, and not less than the geotechnical standard on high mountain. 5.34 Urban quasi-geoid
5.34.1 The resolution of the urban pseudo-geoid shall not be less than 25×25 and its accuracy shall not be less than ±0.05m. 5.3.4.2 The accuracy of the height anomaly difference of the adjacent elevation anomaly control points of the urban quasi-geoid shall not be less than ±0.05m65
Gravity benchmark and force measurement control network
6.1 Gravity benchmark
6.11 National gravity The benchmark is represented by the 2000 National Gravity Basic Network. 6.12 All gravity measurements should be combined with the gravity points in the national gravity benchmark to obtain the gravity value of the measuring point. 6.2 Gravity Control Network
6.21 The purpose of the national gravity measurement control network is to establish and maintain the national gravity benchmark, provide a unified gravity starting value for various gravity measurements, and follow the principle of continuous control to divide it into first-class gravity basic network and second-class gravity points. 6.22 The gravity basic network consists of gravity benchmark points, basic points and their guide points, and includes a certain number of gravity instrument calibration baselines. Its coverage should be effective over the national territory to meet the accuracy requirements of the relative joint measurement of the first-class gravity points and the needs of national economy and national defense construction. The error in the determination of the absolute gravity value of the benchmark point should not be greater than ±5×10m*s-. Relative gravity measurement is carried out between the gravity benchmark point and the basic point and its leading point. The error in the joint measurement of gravity segment difference in relative gravity measurement should not be greater than ±10×10-m6.23 The first-class gravity network is an extension of the basic gravity network and should be arranged in a closed loop. The error in the joint measurement of gravity segment difference between the first-class gravity point and the basic gravity network point should not be greater than ±25×10-m*s-6.24 The second-class gravity point is the encryption of the first-class gravity network. The second-class gravity point is arranged according to the actual needs of the encrypted gravity measurement in different periods and regions. The error in the joint measurement should not be greater than ±250×10-m*s-! 6.25 The calibration baseline of the gravimeter grid value is used to establish the national relative gravity measurement scale benchmark, including the long baseline and the short baseline. The long baseline is laid out in the north-south direction. The difference in gravity between the two ends of the baseline should be greater than 2000×10-m·. Each baseline point should be a gravity reference point: The baseline can be laid out according to GB22021-2008
by region. The difference in gravity between the two ends of the short baseline should be greater than 150×10-m, %, and the relative error of the gravity segment difference should be less than 5×10-6.2.6 The basic gravity network should be measured once every 15 years + each re-measurement should not exceed 2 years 6.3 Intensified gravity measurement
6.3.1. The dense gravity measurement is carried out by determining the fine structure of the earth's gravity field: to establish the national basic grid average gravity anomaly model, determine the geoid, interpolate the astronomical geodetic vertical deviation of the geodetic control point, and correct the normal height system of the precision leveling plate, etc. to provide the earth's gravity field data. The density of the dense gravity points can be determined according to the needs of the project, geographical conditions, quasi-geoid accuracy and other factors. 6.3.2 The error of the gravity joint measurement of the dense gravity points relative to the starting point shall not exceed ±0.60×10-m5-, and can be relaxed to 1.00×10-ms in difficult areas. When it is necessary to jointly measure the second-class gravity points (including the guide points), the second-class gravity points shall be relative to the starting point. The mean error of gravity joint measurement of calculated points shall not exceed ±0.30×10-ms
6.3.3 The mean error of average spatial gravity anomaly of 5°×5 national basic grid shall generally not exceed ±5:0×10-m, and it can be relaxed to ±10×10-m in difficult areas. For the average spatial gravity anomaly of 0×3 grid, the mean error shall generally not exceed 30x10m=s
7 Instrument datum
7.1 The theoretical lowest south level is adopted in coastal waters for the operational datum, and the design water level is adopted in inland waters. 7.2
The depth datum is connected with the national high-tech datum through level joint measurement of tide gauge stations. Strong
China Standards by Publishing House
GB22021-2008
Appendix A
Normative Appendix)
2000 National Geodetic Coordinate System Definition and Reference Sphere Constants The definition and constants of the 2000 National Geodetic Coordinate System (English name ChinaGeodeticCoordinateSystem2000. Abbreviated as CGCS2000) are:
2000 National Geodetic Coordinate System is a right-handed earth-fixed rectangular coordinate system. The origin is at the center of the earth. The Z axis is the multi-polar direction defined by the International Earth Rotation Bureau (IERS). The X axis is the intersection of the Golden Meridian plane defined by the International Earth Rotation Bureau and the equatorial plane perpendicular to the Y axis. The Y axis, Z axis and X axis constitute a right-handed orthogonal coordinate system. The entire earth's center, including the mass center of the earth, the sea and the atmosphere, is a unit of mass in the local earth frame under the sense of relativity. Axis orientation: The initial value of the orientation is determined by the International Time Bureau (BIH), and its time variation is determined under the condition that the entire earth plate moves horizontally without net rotation. The 2000 national geodetic coordinate system has an epoch of 2000, and the basic geodetic parameters use a tidal system. The specific values ​​are as follows: Length half box -6378137m
Geocentric force effect: GM-3.986004418×104m Geodynamic shape factor -0.001082629832258 Earth rotation speed: c-7.292 115×10-rad.a-Reading Special
China Standards
Appendix B
(Normative Appendix)
1985 National Height Datum Definition and Parameters GB220212008
1985 National Height Datum is defined as the average sea level of the Yellow Sea (height starting surface) calculated using the observation data of Qingdao Dagang Tide Station from 1952 to 1979. The level origin of the People's Republic of China is located at Guanxiang Mountain, Qingdao City, with an elevation of 72.260m. Strong
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