Customer Service Center

• PosApp (SimGEN / SimREPLAYplus / SimREPLAY)
• Galileo navigation data

1. Go to menu [Options-->General Options]
2. Enable "Dump navigation data"
3. Run the scenario (normal speed or turbo speed)
4. For Galileo navigation data, PosApp creates binary files called
       - E1 INAV = "Gal_inav_data_L1_B.bin"
       - E5 INAV = "Gal_inav_data_E5b.bin"
       - E5 FNAV = "Gal_fnav_data.bin"
    
5. You can decode the binary files using the following utilities via menu [Tools-->General Utilities]
       - "Galileo Nav Data Extract"

To decode the binary files for yourself, the following explanations are of benefit:-

• First 1 byte is a navigation data type identifier
  • 00 = E5 FNAV
  • 01 = E1 INAV
  • 02 = E5 INAV
• The remainder of the file consists of navigation message records of a fixed length, depending on the nav message type:-
  • Each INAV record is 35 bytes
  • Each FNAV record is 36 bytes
• Each record consists of the following
  • The first 4 bytes is the integer time into run (in seconds)
  • The next 1 byte is the SVID number of the broadcasting satellite
  • The remaining bytes are the navigation message for the specified satellite SVID
    • 30 bytes for INAV
    • 31 bytes for FNAV
• The MSB of the first byte contains the first bit of the message and the LSB contains the eighth bit.
• Where the message length is not a multiple of 8 then the unused, least significant bits of the last byte, should be discarded.
   
• E1 / E5 INAV
  • Navigation message length = 240 bits (odd+even page)
  • 30 bytes * 8 bits = 240 bits  <-- so no unused bits
• E5 FNAV
  • Navigation message length = 244 bits
  • 31 bytes * 8 bits = 248 bits <-- so the last 4 bits of the last byte are discarded

NOTE:
    - PosApp also creates binary 'symbols' files for E1 and E5 INAV ("inav_E5B_symbols.bin" & "inav_L1B_symbols.bin").
    - These are discussed separately - see article FAQ10365