wiki:NDF

Version 8 (modified by stoecker, 8 years ago) ( diff )

Reduce satellite systems bits and use free bit for tracking indicator

This page is dedicated to the development of an RTCM3 Navigation data frames (NDF) message for the transport of raw GNSS messages.

Message header

Data fieldDF NUMBERDATA TYPENO. OF BITSNOTES
Message Number DF002 uint12 12 4075 (proprietary number for this purpose)
Reference Station ID DF003 uint12 12 stream identification
Reserved field uint2 2 reserved bits, maybe used to separate different type 4075 message, always 0 for NDF
Frame Count (FC) uint6 6 Number of frame entries to follow
Frame Entry depends on FC and frame size frame data according to following table
TOTAL 32 + Frames

Frame Entry

Data fieldDF NUMBERDATA TYPENO. OF BITSNOTES
Satellite system uint5 4 0 == GPS, 1 == GLONASS, 2 == Galileo, 3 = SBAS, 4 = QZSS, 5 = BDS
Satellite number uint6 6 Satellite ID, specific for the satellite system always 6 bits (see table below)
Continuous Tracking bit(1) 1 Tracking this satellite frame data was continous (1 = continous, 0 not continues or unset)
Epoch Time uint30 30 Epoch time, specific for the satellite system always 30 bits (see table below)
Signal Type uint5 5 Signal type specification, index from MSM signal mask bit field (see DF395)
Frame Data Size (N) uint12 12 Number of bits to follow
Frame Data N Bit data from satellite (see data section below)
TOTAL 48 + N

Layout of a frame block always follows this structure, so unknown satellite systems or satellites can be skipped in messages with more than one frame.

Satellite ID (equal to MSM)

Satellite systemDF NUMBER(s)NOTES
GPS DF068 1 .. 32
GLONASS DF384 (with 6 bit) 1 .. 24
Galileo DF252 1 .. 36
SBAS 120 == 1, ...
QZSS DF429 (with 6 bit) 192 == 1, ... 202 == 10
BDS 1 .. 37

Epoch Time (accuracy in milli seconds, equal to MSM)

Satellite systemDF NUMBER(s)NOTES
GPS DF004 in milliseconds (0..604799.99 ms)
GLONASS DF416 (3 bit) + DF034 (27 bit) Like for MSM, Day of week (0 == Sunday, 6 == Saturday, 7 == unknown) + time of day in ms (0..86400.999 ms)
Galileo DF248 equals GPS
SBAS equals GPS
QZSS DF428 equals GPS
BDS DF427 similar to GPS, but with a 14 leap second difference

Frame Data

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