ANNEX 1
Loran-C/Chayka protection criteria and signal level determination
guidelines
1 Protection
criteria
2 Signal level
determination guidelines
ANNEX 2
Technical characteristics of a tri‑state pulse position modulation
(3s-PPM) data service using Loran-C and Chayka transmissions in the frequency
band 90-110 kHz
1 Structure
2 Modulation/demodulation
layer
2.1
Pulse modulation
2.1.1 Timing
2.1.2 Modulation balance
2.1.3 Timing accuracy
2.2
Modulation patterns
2.2.1 Pattern/data
translation
2.2.2 No data
transmission pattern
2.3
Message structure
2.4
Blanking
3 FEC layer
3.1
Primitive polynomial
3.2
Generator polynomial
3.3
Order of transmission
3.4
Continuity of modulation
4 Message coding
layer
4.1
Generic structure
4.2 Message
type identification
4.3
Message bodies
4.4
Definitions
4.4.1 Modified Z-count
4.4.2 Scale factor
4.4.3 User differential
range error (UDRE)
4.4.4 Satellite
identification
4.4.5 Pseudorange
correction (PRC)
4.4.6 Range-rate
correction (RRC)
4.4.7 Issue of data (IOD)
4.4.8 Tb of navigation data (TOD)
4.4.9 Sequence number
4.4.10 End of message
(End)
4.4.11 Text characters
4.5
Cyclic redundancy check (CRC)