Abstract: The format of Vaisala DigiCORA®3 DataBase files (DC3DB – "*.dc3db" or "*.dc3") is outlined in this document. DC3DB files are used as measurement and parameter archive files in Vaisala DigiCORA® Sounding Systems MW31 and MW21 for radiosondes. In essence, the files are in proprietary Microsoft DataBase format (MDB – "*.mdb") of Jet version 4.0 with a well defined internal structure. Currently, however, no public documentation of the format in the form used by Vaisala is available.
The GRUAN file archive contains several tens of thousands of radiosounding files in DC3DB format. This extensive archive should be freely available to users for decades, and the data format use of the files should accordingly be documented. This Technical Note summarises the information about the DC3DB file contents and format that is available at the GRUAN Lead Centre.