@author fakgun

1. What is an ISO/IEC 8211 File?

An ISO/IEC 8211 file is a binary data file format designed to be self-describing, meaning it includes the information needed to parse its own structure. It's often used in geospatial datasets like S-57 and S-101 ENCs.

Each Logical Record (both DDR and DR) contains three basic elements:

• Leader • Directory • Field Area

Logical Records in an ISO 8211 File

An ISO 8211 file is a sequence of logical records. In S-101 exchange sets each .000 file contains:

1. One Data Descriptive Record (DDR) (First Record of file similiar to DR but they called DDR because it describes the data)
2. One or more Data Records (DR)

Each logical record follows the same physical structure:

┌───────────────────────────────────────────────────────────────────┐
│ Leader (24 bytes)                                                │
├───────────────────────────────────────────────────────────────────┤
│ Directory (n × 12 bytes entries) + Directory Terminator (0x1E)   │
├───────────────────────────────────────────────────────────────────┤
│ Field Area: Fields (with their own terminators)                 │
│  …                                                              │
├───────────────────────────────────────────────────────────────────┤
│ Record Terminator (Field Terminator, 0x1E)                      │
└───────────────────────────────────────────────────────────────────┘

ISO 8211 File

[DDR Record]
└── Leader
└── Directory (tags → locations of fields)
└── Field Area
    └── Field 0001: 
    └── Field 0002: 
    └── Field 0003: 
    └── ...

[Data Record 1]
└── Leader
└── Directory
└── Field Area

[Data Record 2]
└── Leader
└── Directory
└── Field Area

[Data Record 3]
└── ...

The ISO file preview document found on internet https://cdn.standards.iteh.ai/samples/20305/1c6d074d5aec4348b1eb2bfbcffc6260/ISO-IEC-8211-1994.pdf 📕

Referenced Documents

• https://iho.int/uploads/user/Services and Standards/S-100WG/S-100WG7/S100WG7-4.16_2022_EN_ISO_IEC8211_Summary.pdf
• https://iho.int/uploads/user/pubs/standards/s-100/S-100_5.2.0_Final_Clean.pdf S-100 Detailed
• https://iho.int/uploads/user/Services and Standards/S-100WG/MISC/US_S100-Part10a.pdf?utm_source=chatgpt.com -S-100 – Part 10a -ISO/IEC 8211 Encoding

The First Record is DDR (Data Descriptive Record)