read
Read only the UHL/DSI/ACC headers from a DTED file on disk. Reads the first 3428 bytes and closes the handle — useful when indexing a library of tiles without loading the elevation grid (~26 MB for .dt2). iOS analogue of the JVM readMetadata overload.
Read the full UHL/DSI/ACC headers (first 3428 bytes) — when the DTED level/classification are needed.