The general objective of the summary file is to provide enough information for a user to be able to position the tape to a desired time period or item of data. Toward this end, the summary file almost always provides a correlated list of file number and data date/time or, alternately, the file number related to a platform or data system name. Information on the tape format is often provided in the summary file, either explicitly, or encoded in the RDP name for that file.
For radar data (which make up the bulk of the RDP archives), the content is highly stylized, providing a list of file number, filename (in an RDP radar filenaming convention), and file length (in bytes). A typical line from an ATD radar tape summary file has the format:
nn plt_yymmdd.hhmm_fmt byte_lenHere,
nn = file_number plt = platform_name yymmdd = date of data in yymmdd format hhmm = time of data (timezone unspecified) fmt = data formatNote that the length of these field components may vary somewhat, and that, on occasion, the format information may be missing (in which case ATD radar Field Format is generally assumed), or the format may appear in place of the platform name. For an example of an ATD "field format" radar summary file, click here; for an example of an ELDORA radar summary file (in DORADE format), click here. Finally, for an example of an ELDORA radar summary file in Universal Format, click here.
For UNIX "tar" tapes, information is generally less stylized (but somewhat more specific!). For an example of summary information for an SSSF Sounding tape (data from TOGA-COARE), click here.