MIL-PRF-89037, PERFORMANCE SPECIFICATION: DIGITAL TOPOGRAPHIC DATA (DTOP) (25 MAY 1999) [MIL-PRF-0089037 USED IN LIEU OF MIL-PRF-89037]., This product specification defines the content and format requirements for the National Imagery and Mapping Agency's (NIMA) Digital Topographic Data (DTOP) files in Vector Product Format (VPF). This product will replace the current digital Interim Terrain Data (ITD) and Vector Product Interim Terrain Data (VITD) products for users requiring Terrain Analysis type data on Compact Disc - Read Only Memory (CD-ROM).