General Information
The universal ship borne Automatic Identification System (AIS) was created for efficient exchange of navigational data among ships and between ships and stations ashore to improve safety of navigation.
Usage:
§ Worldwide radio system for ship collision avoidance and navigational advice.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation, primary / secondary |
FM / GMSK |
|
|
BT product 12.5 kHz / 25 kHz |
0.3 or 0.5 / max 0.5 |
|
|
Symbol rate (Bd) |
9600 |
|
|
Coding |
NRZI and CRC |
|
Demodulator Settings |
Demodulator |
G (MSK) |
|
|
Type |
GMSK |
|
|
Symbol rate (Bd) |
9600 |
|
|
SR tolerance (Bd) |
20.000 |
|
|
BT |
0.40 |
|
|
Min. burst length (s) |
0.040 |
|
|
Max. burst length (s) |
0.080 |
|
|
Min. pause length (s) |
0.440 |
|
Features |
Demodulation |
yes |
|
|
Recognition |
yes |
|
|
Decoding |
yes |
|
|
Automatic Polarity Adjustment |
yes |
|
|
Combination with other modems (modem list) |
yes |
|
Tuning |
The tuning frequency is 11.340 kHz above the pilot-tone | |
|
Frequencies |
161.975 MHz 162.025 MHz | |
Table 2: AIS
Figure 2: AIS Spectrogram