Type 0 Extension 10 - mattpascoe135/dab GitHub Wiki

#Extension 10 - Date and time (d&t) The date and time feature is used to signal a location-independent timing reference in UTC format. This feature is encoded in Extension 10 of FIG type 0 (FIG 0/10). Figure 46 shows the structure of the date and time field which is part of the Type 0 field (see also figure 4). The time reference shall be defined by the synchronization channel (see clause 14.3.3).

The following definitions apply:

###Rfu: this 1-bit field shall be reserved for future use of the remainder of the Type 0 field for extension 10. The bit shall be set to zero for the currently specified definition of this field.

###MJD (Modified Julian Date): this 17-bit binary number shall define the current date according to the Modified Julian coding strategy (see EN 62106 [5]). This number increments daily at 0000 Co-ordinated Universal Time (UTC) and extends over the range 0-99 999. As an example, MJD 50 000 corresponds to 1995 October 10.

###LSI (Leap Second Indicator): this 1-bit flag shall be set to "1" throughout a UTC day containing a leap second.

###Conf. Ind. (Confidence Indicator): this 1-bit field shall be set to "1" when the timing information is within an agreed tolerance (for example, ±0,2 ms at first ground fall).

###UTC flag: this 1-bit field shall indicate whether the UTC (see below) takes the short form or the long form, as follows:

0: UTC short form;

1: UTC long form.

##UTC (Co-ordinated Universal Time): two forms are available depending upon the state of the UTC flag. They shall be defined as follows:

###short form: this 11-bit field contains two sub-fields, coded as unsigned binary numbers. The first sub-field is a 5-bit field which shall define the hours and the other sub-field is a 6-bit field which shall define the minutes;

###long form: in addition to the hours and minutes fields defined in the short form, this 27-bit field shall contain two further sub-fields, both of which shall be coded as unsigned binary numbers. The first is a 6-bit field which shall define the seconds and the other is a 10-bit field which shall define the milliseconds.