NavCom Sapphire Rev.J - Manual (Page 272)

Sapphire Technical Reference Manual Rev. J
272
2.19 EPHEM1B (Version 1; v1.0.0.4) (Binary)
SF-3050 Sapphire SF-3040
This record contains the packed ephemeris data for a satellite. Table 120 lists the message
structure; descriptions of the fields can be found in the sections indicated.
Table 120: EPHEM1B Binary Message Header
Data Item Data Type Section
Satellite type (-1=NONE, 0=GPS,
1=GALILEO, 2=SBAS, 3=GLONASS)
U08
Ephemeris data 2.19.1 to 2.19.3
2.19.1 GPS Ephemeris
Table 121: GPS EPHEM1B Binary Message
Data Item (73 Bytes) Data Type
PRN (1-32) U08
Subframe 1 (3 words * 8 bytes) 24 bytes
Subframe 2 (3 words * 8 bytes) 24 bytes
Subframe 3 (3 words * 8 bytes) 24 bytes
2.19.2 GLONASS Ephemeris
This record contains the packed ephemeris data for a GLONASS satellite (string 1, 2
and 3, 4). Table 122 lists the message structure.
Table 122: GLONASS EPHEM1B Binary Message
Data Item (49 Bytes) Data Type
PRN (1-24) U08
string 1 (3 words * 4 bytes) 12 bytes
string 2 (3 words * 4 bytes) 12 bytes
string 3 (3 words * 4 bytes) 12 bytes
string 4 (3 words * 4 bytes) 12 bytes
Each string is in the order of word0, word1, and word2.The first bit of the string number
field is the MSB of word0, and the last bit of the Hamming code (KX) field is the LSB of
word2. The bit mapping example of string 1 is listed in Table 123.