BS ISO 11104:2011 - Page 2

Space data and information transfer systems. Time code formats. | Status: Current, Under review

1 Scope This International Standard establishes a small number of standardized recommended time code formats for use in data interchange applications between agencies of the CCSDS. This International Standard does not address timing performance issues such as stability, precision, accuracy, etc. Time codes are digital representations of time information. This International Standard describes four standard recommended time codes (one "unsegmented" and three "segmented" codes) which use the international standard second as the fundamental unit of time. An unsegmented time code is a pure binary count of time units and fractional time units from a starting time called the "epoch". A segmented time code is one in which the count of time units and fractional time units is accumulated in two or more cascaded counters which count modulo of various bases and start from the epoch. The scope and field of application are furthermore detailed in subclauses 1.2 to 1.4 of the enclosed CCSDS publication.