The current S-57 standard mainly regulates marine object data encoding, but lacks specificity for military nautical charts and Inland Electronic Navigation Charts (IENC). To adapt to complex inland environments, diversified waterways and new data requirements, it's necessary to extend object types and related rules.

• Chart data storage structure and extension logic: An object entity consists of a unique feature object and one or more spatial objects. When extending objects, corresponding adjustments should be made to their characteristic attributes, display rules and datasource inspection standards to maintain consistency.
• Practical applications of standard extensions include: 

  • Inland waterway adaptation: Dynamically adjust data to accommodate different channel depths, widths and hydrological conditions.

  • New data content: Extend specific objects like bridge heights or inland hydrological information.

  • Display and inspection rules: Ensure extended data can be correctly displayed and pass standardized checks.

• SuperMap iDesktopX supported standard extensions feature:

  • Quick reusability: Modify based on existing standards (e.g., inland standards)

  • User-friendly configuration: Achieve settings through XML files without complex logic

  • Multi-platform adaptation: Extended content works across components, desktop and server products

This chapter covers:

• Extend Feature: Add new objects compliant with S-57, CJ-57 and IENC standards for special scenarios.
• Extend Attribute: Add new attribute types compliant with S-57, CJ-57 and IENC standards for special scenarios.
• Search Feature Definition: Query object definitions (codes, fields and explanations) to support extensions.
• S-52 Display Extension: Customize display rules for new objects or attributes.
• S-58 Inspection Extension: Add datasource inspection rules for extended objects to ensure data consistency and accuracy.