MIL-PRF-89020B, PERFORMANCE SPECIFICATION: DIGITAL TERRAIN ELEVATION DATA (23 MAY 2000)., This specification defines the requirements within National Imagery and Mapping Agency's (NIMA) Digital Terrain Elevation Data Base which supports various weapon and training systems. This edition includes the Shuttle Radar Topography Mission (SRTM) DTED Level 1 and Level 2 requirements.