GB12327-2022
Specifications for hydrographic survey
海道测量规范
GB 12327-2022 is a current mandatory Chinese national standard for Specifications for hydrographic survey. It appears in the Machinery compliance cluster with a product safety focus and has an implementation date of Feb 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 basic content, measurement methods, accuracy indicators, and technical requirements for hydrographic surveys. It is applicable to various scales of hydrographic surveying activities in China's marine and inland waters, including control surveys, water depth measurements, and coastal topographic surveys. This standard is mandatory for all hydrographic surveying activities within Chinese jurisdiction. It does not apply to specialized oceanographic research surveys not intended for navigational safety.
Technical requirements
The standard outlines comprehensive technical requirements for establishing horizontal and vertical control networks. It specifies the use of the CGCS2000 coordinate system and the 1985 National Height Datum. Surveyors must establish hydrographic control points and mapping points based on national control networks. The requirements cover GNSS control surveys, leveling, and traverse measurements, detailing accuracy metrics for different control point classes such as H1, H2, and Hc. For water depth measurements, the standard classifies surveys into five grades (Grade 1 to Grade 5) based on seafloor coverage and target detection capabilities. It mandates specific equipment usage, including single-beam, multi-beam, and airborne laser sounding systems, depending on the survey grade and water depth. Full coverage bathymetric surveys are required for critical navigational waters like ports, channels, and anchorages. The standard also details procedures for sound velocity profiling and water level corrections to ensure depth accuracy. The standard sets forth requirements for sweeping surveys using side-scan sonar, synthetic aperture sonar, and other devices to detect navigational hazards. It also covers hydrological observations (temperature, salinity, currents) and bottom sediment exploration. Accurate determination of the coastline and dry beach topography is essential for coastal mapping. The technical requirements ensure that all collected data reliably reflects the underwater and coastal topography for safe navigation.
Testing methods
The standard describes various testing and evaluation methods, including main and check line cross-point comparisons for depth accuracy, and instrument calibration procedures for multi-beam and single-beam echo sounders. It outlines methods for sound velocity profile measurements using CTD or direct sound velocity profilers. For water level control, it specifies tidal harmonic analysis and datum transfer methods to establish the theoretical lowest tide surface. Additionally, it details side-scan sonar target detection verification and GNSS positioning accuracy assessments through internal and external conformity checks.
FAQs
What products or activities are regulated under GB 12327-2022?
GB 12327-2022 regulates all hydrographic surveying activities in China, including water depth measurements, coastal topographic surveys, and sweeping surveys intended to ensure navigational safety.
What are the main updates in GB 12327-2022 compared to the 1998 version?
The 2022 version introduces a five-tier classification for water depth surveys, adds requirements for GNSS control surveys and airborne laser sounding, and updates methods for water level control and sweeping surveys. It also removes outdated manual operation and analog correction methods.
Does GB 12327-2022 align with international hydrographic standards?
While GB 12327-2022 is tailored to China's specific geographic and regulatory environment, its technical requirements for survey accuracy, multi-beam usage, and datum determination are conceptually aligned with international standards like the IHO S-44.
The summary above provides a high-level overview of GB 12327-2022. To ensure complete compliance for your hydrographic surveying projects in Chinese waters, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 12327-2022 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 12327-1998