The reference station ID is determined by the service provider. Its main purpose is to link all message data to its unique source
DF051
Modified Julian Day (MJD) Number
0-65,535 d
1 d
uint16
(MJD) is a running count of the number of days since midnight, November 17, 1858. For example, the first day of GPS week 0 has MJD 44244. The full MJD number should always be transmitted. Currently, the rollover of the MJD is far off, but experience with the Y2K problem has shown that the actual lifespan of software and applications can be much longer than expected. Therefore, it is expected that the MJD will roll over in calendar year 2038. On MJD day 65536, the counter will start again at 0.
DF052
Seconds of Day (UTC)
0-86,400 s
1s
uint17
The Seconds Of Day (UTC) is the number of seconds in a day measured from midnight, with the green indicating the appropriate leap seconds. ich time. The GPS seconds must be adjusted every week 86400 - a leap second has been issued.
DF053
Number of Message ID Announcements to Follow (Nm)
0-31
1
uint5
The number of Message ID announcements that follow informs the receiver of the number of message types and how often the reference station broadcasts. When this value is zero, it indicates that there are no Message ID announcements present, or that there are more than 31 Message ID announcements that follow. The actual number of Message ID announcements present in a Type 1013 can be determined by taking into account the Message Length field found in the frame structure, using the formula: Actual Number of Message IDs = floor((8*message_Length-70)/29)
DF054
Leap Seconds, GPS-UTC
0-254 s
1s
uint8
Please refer to the GPS/SPS signal specifications provided by the U.S. Coast Guard Navigational Information Service. 255 - The value was not provided.
DF055
Message ID
0-4095
1
uint12
Each message lists the message ID that the reference station sent.
