2813 Common Data Format dotCDF 3.x Dataset Common Data Format is a library and toolkit that was developed by the National Space Science Data Center (NSSDC) at NASA, used for the storage and processing of multi-dimensional datasets. The ‘dotCDF’ file as described in the specification refers specifically to the filetype with extension .cdf. The dotCDF file may be a standalone file containing everything it needs, or it may have companion ‘variable’ files with the extension .vX, where X represents an incrementing numeric value, e.g. .v0, .v1 etc. This entry covers versions 3.x. Version 3.x introduced 8-byte (64bit) record sizes and offsets. 244 Preservica / Preservica 11 Apr 2024 11 Apr 2024 fdd000226 Library of Congress Format Description Identifier fmt/1950 PUID Q1116060 Wikidata QID Identifier cdf File extension 2295 CDF 3.x BOF; Offset:0; Magic number 0xCDF30001, then either 0x0000FFFF if uncompressed, or 0xCCCC0001 if compressed, then an 8 byte variable value representing the size of the ‘CDF Descriptor Record’, followed by the 4 byte ‘RecordType’, which for the CDF Descriptor Record is 0x00000001. There are additional elements in the CDF Descriptor Record that may be used to strengthen the signature is required, and potentially to further divide into separate sub-versions if required. Specifications can be found on the Internet Archive: https://web.archive.org/web/20150922063622/http://nssdcftp.gsfc.nasa.gov/standards/cdf/doc/ or https://cdaweb.gsfc.nasa.gov/pub/software/cdf/dist/obsolete/ 1 Absolute from BOF 0 0 CDF30001(0000FFFF|CCCC0001){8}00000001 Is subsequent version of 2812 Common Data Format dotCDF