S57 Map ENC Layer Analysis: Display of Electronic Chart Symbols and Position Data

# 1. Introduction

### 1.1 Overview of S57 ENC Chart Layers
The S57 chart is an international standard electronic nautical chart format established by the International Hydrographic Organization (IHO), primarily used to provide detailed nautical data in the maritime domain.

### 1.2 Importance of Electronic Charts in Maritime Operations
Electronic Navigational Charts (ENC) are indispensable tools in navigation, offering real-time, accurate positional data and chart information, aiding navigators in making correct decisions and ensuring safe voyages.

### 1.3 Overview of Contents
This article aims to provide an in-depth analysis of the S57 chart ENC layers, encompassing an introduction to the S57 format, the composition and structure of ENC layers, as well as the classification and meanings of electronic chart symbols, with the intent of enhancing readers' understanding of the symbology and display of position data in electronic charts.

# 2. Analysis of S57 ENC Chart Layers

In this chapter, we will delve into the analysis of S57 ENC chart layers, including an overview of the format, the composition and structure of the layers, and the ENC symbol system and standardization. Let's explore these aspects together.

### 2.1 Introduction to the S57 Format
S57 is an international standard electronic chart data format developed by the International Maritime Organization (IMO). It employs vector data to store chart information, offering a highly flexible and standardized data structure for use in various applications.

### 2.2 Composition and Structure of ENC Layers
ENC layers typically comprise multiple elements such as depth, buoys, rocks, and channels. Each element has corresponding attribute information, including position, name, and type. These elements are organized into a specific hierarchical structure for efficient data management and retrieval.

### 2.3 ENC Symbol System and Standardization
To ensure consistency and visual effectiveness in electronic charts, the S57 standard defines a symbol system representing the graphical symbols and styles of different elements. These symbols are designed and maintained according to standard specifications, ensuring consistency and comparability between various charts.

By analyzing the S57 ENC chart layers, we can better comprehend the organizational structure of electronic chart data and symbol standardization, laying the groundwork for subsequent electronic chart symbol parsing and position data display.

# 3. Electronic Chart Symbol Analysis

As a vital tool in the maritime domain, symbols in electronic charts play a crucial role. Through the analysis of electronic chart symbols, navigators can better understand chart information and make navigational decisions.

#### 3.1 Classification and Meanings of Electronic Chart Symbols

Electronic chart symbols can be classified according to the objects and meanings they represent, commonly including buoys, navigation marks, rocks, vessels, and depth. Each symbol represents a specific maritime object or piece of information, and navigators need to be familiar with these symbol meanings to accurately interpret chart information.

#### 3.2 Examples of Common Electronic Chart Symbol Analysis

The following are some examples of common electronic chart symbols and their meanings:

- Buoy symbols: Represent floating buoys in the water, used to identify channels, obstacles, and other i