SEGY-SAK

Map trace headers to labelled dimensions without losing the original survey geometry. Header byte assignments are evidence to inspect, not safe guesses.

Before opening

Inspect format/endian, trace count, sample count/interval, delay recording time, inline/crossline or CDP headers, coordinate units and scalar. SEG-Y sample intervals are stored in microseconds; the backend's vertical samples use milliseconds for ordinary time sections. A depth section needs an explicit depth convention. Confirm actual data units before labelling an axis.

Check dimension key uniqueness and missing traces. Sparse or irregular geometry may not form a complete rectangular cube. Keep the original trace index for exports. A dimension byte offset is one-based SEG-Y numbering (CDP ensemble is 21, inline is 189, crossline is 193); some upstream old examples use a wrong CDP offset. Use the actual file's header convention.