## AIS Setup

| Menu path |
|-------------|
| {{ menu }} → {{ settings }} → Sensors → Add sensor → AIS |

The sensor connection and setup are performed in accordance with the {doc}`procedure </sections/sensors/navigation-sensors/index>`.

```{caution}
Connection, setup, and modification of AIS sensor settings must be performed by a qualified specialist.
```

```{attention}
The following should be considered:

- When both **AIS** and **ARPA** sensors are simultaneously connected to ECDIS, AIS target data in ECDIS may come from either ARPA or AIS;
- ARPA transmits AIS target data in sentences: `$--TTD`, `$--TTM`, and `$--TLB`;
- An AIS target received from ARPA will be displayed as an AIS target;
- AIS target data received from ARPA will be incomplete;
- ARPA does not relay text addressed and broadcast messages from AIS;
- If data about the same target is received in ECDIS from both ARPA and AIS, the target will be displayed as associated;
- AIS target data will be complete;
- ARPA sentences are configured in the {doc}`ARPA </sections/sensors/arpa/arpa-setup/index>` sensor settings;
```

Ensure that the sensor settings correctly configure the processing of received messages: header and type processing is enabled, checksum verification is enabled.

ECDIS receives the following messages:

- **Messages 1, 2, 3, and 5** — AIS Class A and AIS-SART
- **Messages 18, 19, and 24** — AIS Class B
- **Message 9** — SAR aircraft AIS
- **Message 21** — AIS AtoN (Aids to Navigation)
- **Messages 12 and 14** — MSI messages (Maritime Safety Information)
- **Messages 6 and 8** — Addressed and broadcast messages (ASM and text)
- **Message 4** — Base station report
- **Message 27** — Long-range automatic identification system broadcast message

AIS message headers:

- **AI** — Mobile AIS station
- **AR** — NMEA 4.0 AIS Receiving Station
- **RA** -- Radar

After configuring and enabling the AIS sensor, the **AIS** window will become available in the **Multifunction window**.

```{attention}
After connecting AIS, enable the AIS layer in the {doc}`Operational settings </sections/graphical-user-interface/operational-settings/index>` to display AIS targets, ASM, and synthetic targets.
```

```{tip}
If the AIS sensor is configured to receive `$--VDM` and `$--VDO` messages, but `$--VDM` is not being broadcast, the AIS will still be considered operational. This is because, in the absence of reports from other vessels, the message is not transmitted. At the same time, the own ship report transmitted in `$--VDO` is mandatory.
```
