空间数据和信息传输系统.时间码格式

[中文适用范围]： 本国际标准为CCSDS各机构之间的数据交换应用建立少量标准化的推荐时间码格式。本国际标准不解决计时性能问题，如稳定性、精度、准确度等。时间码是时间信息的数字表示。本国际标准描述了四种标准推荐时间码（一种“非分段”和三种“分段”码），它们使用国际标准秒作为时间的基本单位。非分段时间码是从称为“历元”的起始时间开始的时间单位和分数时间单位的纯二进制计数。分段时间码是时间单位和分数时间单位的计数在两个或多个级联计数器中累积的码，这些计数器以各种基数进行模计数并从历元开始。范围和适用领域在附带的CCSDS出版物的小节1.2至1.4中详细说明。 [外文原描述]： ISO 11104:2011 establishes a small number of standardized recommended time code formats for use in data interchange applications between agencies of the CCSDS. ISO 11104:2011 does not address timing performance issues such as stability, precision, accuracy, etc. Time codes are digital representations of time information. ISO 11104:2011 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.