MATLAB Source Code Implementation for Reading SEGY Files

SEGY file is a common binary data format widely used for storing seismic exploration data. Reading SEGY files in MATLAB requires parsing the file structure and storage methodology to correctly extract the contained data.

### 1. SEGY File Structure SEGY files typically consist of three main components: Text Header: Contains descriptive information about the file, usually encoded in ASCII or EBCDIC format. Binary Header: Stores critical parameters including sample rate, number of samples per trace, and trace count, using binary storage format. Trace Data: Contains actual seismic data, typically stored as floating-point or integer values.

### 2. MATLAB Implementation Approach for Reading SEGY Files Since SEGY files are in binary format, MATLAB provides functions like `fread` for reading. The parsing procedure involves: File Opening: Use `fopen` to open the SEGY file with proper byte order specification (big-endian or little-endian). Text Header Reading: The text header typically consists of 3200 bytes of ASCII characters, which can be read using `fread` with `char` conversion. Binary Header Parsing: The binary header usually occupies 400 bytes containing information such as samples per trace, sample interval, and trace count. Extract relevant bytes according to SEGY format specifications. Seismic Data Extraction: Based on samples per trace and trace count recorded in the binary header, read data trace by trace and store as a matrix organized by sample points.

### 3. Important Considerations Byte Order Issues: SEGY files generated by different systems may use different byte orders (big-endian or little-endian), requiring proper configuration. Data Format Conversion: SEGY data may be stored in IBM floating-point, IEEE floating-point, or integer formats, necessitating appropriate data type conversions. Performance Optimization: For large SEGY files, implement trace-by-trace reading to conserve memory and avoid loading entire datasets at once.

Following this methodology enables efficient SEGY file reading in MATLAB, facilitating subsequent seismic data processing or visualization analysis.