performance specification digital terrain elevation data

MIL-PRF-89020Bc. Record sequence.VOL 1 (Volume Header Label)HDR 1 (Header Label for file A)UHL 1 (User Header Label for file A)*DSI (Data Set Identification Record for file A)ACC (Accuracy Description Record for file A)DATA (for file A)*EOF 1 (End of File for file A)UTL 1 (User Trailer Label for file A)*HDR 1 (Header Label for file B)UHL 1 (User Header Label for file B)*DSI (Data Set Identification Record for file B)ACC (Accuracy Description Record for file B)DATA (for file B)*EOF 1 (End of File for file B)UTL 1 (User Trailer Label for file B)**Note: In the above sequence a Tape Mark (hardware end of file) i sdenoted by an “*”.3.8 NIMA Gateway. Digital Terrain Elevation Data can be accessedthrough the NIMA Gateway via the World-Wide-Web (WWW), the Open SourceInformation System (OSIS), Secure Internet Protocol Router Network (SIPRNET)or the Joint Worldwide Intelligence Communication System (JWICS). DTED Level0 can be downloaded from the WWW, OSIS, SIPRNET and JWICS. DTED Level 1 andLevel 2 can be downloaded from the OSIS, SIPRNET and JWICS. The DTED filesare encapsulated and compressed into one file for downloading. Detailedinstructions for downloading and decompression are available on the webpages.3.9 DTED File descriptions on CD-ROM or from the Gateway. The threeclasses of DTED are known as DTED Level 0, DTED Level 1, and DTED Level 2.Each DTED class consists of a different set of files.DTED File TypesDTED Level 0consists of six filetypes.onc.dir.dt0.avg.min.maxdmed.DTED Level 1 consistsof eight file types.onc.dir.dt1Read.medmed.gazetteer directory.gaz.hshGazette.dirGazette.keyDTED Level 2 consistsof four file types.onc.dir.dt2Read.medmed.7