GB12320-2022
Compilation specifications for Chinese nautical charts
中国航海图编绘规范
GB 12320-2022 is a current mandatory Chinese national standard for Compilation specifications for Chinese nautical charts. It appears in the Machinery compliance cluster with a product safety focus and has an implementation date of Aug 1, 2023.
Applicability depends on product scope, certification route, competent authority notices and transition rules. Requst for the translation or verify source before using this record in a compliance decision.
Compliance overview
Scope and applicability
This standard specifies the compilation specifications for Chinese nautical charts. It applies to the compilation of various scale nautical charts, including general charts, navigation charts, and harbor plans. It is mandatory for hydrographic mapping, naval navigation, and maritime cartography within Chinese waters and for charts covering foreign and polar regions produced by Chinese authorities. It is not applicable to terrestrial topographic maps or inland river charts not intended for maritime navigation.
Technical requirements
The standard outlines the mathematical foundation for nautical charts, strictly requiring the use of the 2000 National Geodetic Coordinate System (CGCS2000) and specifying the application of Mercator and Universal Polar Stereographic projections based on latitude. It defines precise rules for chart sheet dimensions, free subdivision principles, and a structured numbering system based on global ocean regions. Cartographers must strictly follow these mathematical and framing parameters to ensure navigational consistency. For cartographic representation, the standard details the generalization and selection criteria for various maritime and terrestrial elements. This includes specific requirements for depicting coastlines, islands, water depths, reefs, wrecks, and navigational aids. It emphasizes the principle of prioritizing navigational safety, such as "selecting shallower over deeper" waters and "selecting higher over lower" elevations for obstacles. Accurate representation of navigational hazards and aids to navigation is the core focus of these technical requirements. Additionally, the standard mandates comprehensive quality control and updating protocols. It introduces concepts like specimen charts for press and print charts for press, replacing older manual proofing concepts. It requires a two-level inspection and one-level acceptance system to verify mathematical accuracy, logical consistency, and cartographic scientific quality. Charts must be continuously updated using the latest notices to mariners to maintain their validity.
Testing methods
The standard specifies rigorous accuracy verification methods for cartographic calculations and graphic rendering. This includes checking map errors (e.g., calculation errors <0.1mm, gridline errors <0.2mm) and verifying the positional accuracy of point, line, and depth elements. It also outlines evaluation procedures for cartographic generalization and data conversion accuracy during the digital mapping process.
FAQs
What products are regulated under GB 12320-2022?
GB 12320-2022 applies to the compilation and drafting of Chinese nautical charts at all scales. It is designed for use by hydrographic offices, naval mapping authorities, and digital cartography providers creating navigational charts for Chinese and international waters.
Are there any updates from the previous version of GB 12320?
The 2022 revision deletes outdated manual drafting methods and introduces digital cartography requirements. It updates the coordinate system to CGCS2000, adds mapping rules for foreign and polar regions, and modifies depth density and contour interval indicators.
How does GB 12320-2022 differ from international hydrographic standards?
While GB 12320-2022 adopts internationally recognized concepts like the Mercator projection and WGS-84 compatibility, it specifically mandates the use of China's national coordinate system (CGCS2000) and national depth/elevation benchmarks for Chinese territorial waters.
The summary above provides a high-level overview of GB 12320-2022. To ensure complete compliance for your products entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 12320-2022 today to access all detailed parameters, tables, and testing procedures.
Applicability hints
- Type
- Safety
- CCS
- A76
- ICS
- 07.040
- Competent department
- Chinese Navy
- Technical committee
- Chinese Navy
Relationships
Replaces:GB 12320-1998