S-65 ENCs: Production, maintenance and distribution guidance
|Full name||S-65, ENCs: Production, maintenance and distribution guidance|
|Type of standard|| IHO International Standard|
|Application||S-65 provides guidelines for the production, maintenance and distribution of Electronic Navigational Charts (ENCs).|
|Conformance classes||None specified|
This document provides a high level guide to the production, maintenance and distribution of Electronic Navigational Charts (ENCs). It offers a framework to inform hydrographical offices of the processes and requirements necessary to produce, maintain and distribute ENCs. It provides references to documentation, which can support each stage of the process. It is not intended to serve as a technical reference manual but to enable hydrographical offices to gain an overview of ENC production processes, and the requirements and procedures that need to be in place to set up an ENC production facility.
S-65 enables Hydrographic Offices to gain an overview of ENC production processes, and the requirements and procedures that need to be in place to set up an ENC production facility. The process promotes accuracy and consistency across borders, provides up-to-date information in a timely manner, and satisfies user needs for safety in navigation.
ENCs consist of digitized data conforming to the specification set out in S-57 IHO transfer standard for digital hydrographic data which record the relevant charted features necessary for safe navigation, such as coastlines, bathymetry, buoys and lights. The basic unit of geographic coverage for ENC is called a cell. S-65 describes the entire ENC process from production to distribution, and provides guidelines to hydrographical offices on the process and requirements. The following stages form part of this process:
- Design production process
This stage consists of two steps: production method and quality system. During the production method, decisions on the source material are made. These depend on factors such as the quality and format of existing survey data, availability of accurately transformed data, and the facilities to produce rectified raster images. After the decisions on the source materials have been made, the production process is designed and a Quality Management System (QMS) is developed. Procedures should be in place at all the stages of the production process to ensure accuracy and consistency. Quality control and quality assurance are important during the production of ENCs.
- Define ENC production requirements
The following steps are recommended to each Regional Hydrographic Commission (RHC): identify key shipping routes and ports within the region, identify charts covering these routes and ports to be captured as ENCs, identify producer nations for ENCs, and arrange for their production. The national production plan shall define which geographic areas are to be captured, which navigational purposes are to be populated for each area, how the areas are to be divided into cells for each navigational purpose, and the order of capture. This plan depends on factors, such as the liaisons with bordering countries and priority traffic routes, to name a few.
- Acquire production system
The production system should depend on the production plan and the extent of data capturing that will be contracted out. Dependencies should be specified in the statement of requirements. There are two main types of production systems. The first type populates and maintain a database of ENC objects, attributes and attribute values in a format that is conformant with S-57. The second type creates individual flat files for each single ENC cell.
- Obtain and train staff
The data should be structured and follow other requirements as set out in S-57. The content of the ENC, limits of the cells and cell navigation purpose are not covered in S-57 and should be decided upon.
- Prepare specification for data capture
- Capture data for new cells
Data can be captured in-house or contracted out. The United Kingdom Hydrographic Office (UKHO) data capture specifications and quality procedures are recommended.
- Edge match data
It is important that the borders of cells with the same navigational purpose match, and accuracy should always be kept in mind. The cells should also match between countries and the hydrographical offices should collaborate to achieve this.
- Verify and validate data
Verification and validation are important to ensure that the ENC cell content is accurate and consistent. Cells need to be checked for content and capture accuracy. Validation checks as specified in S-58 IHO Recommended ENC validation checks should be performed.
- Maintain ENCs
After the ENC cell has been produced and distributed to the end users, the data should be maintained. The overall Quality Management System should include a mechanism for updating the cell design to meet the user needs. The processes for updating paper charts and ENCs should be synchronised. When an update is performed or a new edition is available, a Notice to Mariners is published.
- Distribute ENC data
The distribution mechanism shall provide users with up-to-date ENC data in a timely manner to ensure safe navigation. The distribution system shall also ensure data integrity and data protection. The system should allow automatic updates of ENC data.
- Design production process