#### Radar Overlay

Radar imagery overlay is enabled in the **Operational settings**.

```{important}
Correct **radar imagery** overlay requires heading data from the **heading sensor**.
```

ECDIS provides quick access to **Radar overlay settings:**

| Menu path |
|-------------|
| {{ menu }} → {{ menu_radar_overlay }} |

![Radar overlay settings](images/Overlay_2.png)

| No. | Parameter | Description |
|---|----------|----------|
| **1** | **Selector** | Manufacturer name |
| **2** | **Radar Overlay Color** | Radar name — entered during installation |
| **3** | **Transparency** | **Radar imagery** transparency adjustment |
| **4** | **Brightness** | **Radar imagery** brightness adjustment |
| **5** | **Contrast** | **Radar imagery** contrast adjustment |
| **6** | **Signal adjustment** | Display of radar console settings. Adjustment from ECDIS is not available. Signal adjustment is possible only when the radar imagery source transmits raw signal and processing can be performed on the ECDIS side. |
| **7** | **Auto** | Automatic gain adjustment. Signal adjustment is possible only when the radar imagery source transmits raw signal and processing can be performed on the ECDIS side. |
| **8** | **Radar image range** | Selection of **radar imagery** display distance. Does not change the range on the Radar. When the **radar imagery** range is changed, the radius of the displayed image increases. The displayed **radar imagery** cannot be larger than the range set on the Radar console. |
| **9** | **Transmit** | Transmission indicator. Does not control high-power transmission activation on the radar |

**Radar overlay settings** contain controls for all connected radar imagery sources, which are grouped into sections. Above each section is the source name and a toggle switch to enable/disable the source.

```{tip}
ECDIS supports simultaneous use of only **one** radar imagery source.
```

```{important}
**For the navigator:** Radar imagery on the chart allows:
- Visually monitoring the correspondence between radar targets and cartographic information
- Identifying objects not displayed on the chart (ice, floating objects, small vessels without AIS)
- Assessing radar operational efficiency in real time
```

```{warning}
**Radar imagery limitations:**
- Radar imagery may not display small objects (wooden vessels, small yachts, ice)
- In heavy sea and precipitation conditions, radar imagery quality may deteriorate
- Radar shadows may conceal targets behind large objects
- Radar imagery does not replace visual observation and other navigation aids
```

The **radar imagery** color is selected manually by the navigator, in accordance with their experience, skills, preferences, and prevailing circumstances. The color selection must exclude the possibility of incorrect reading of **radar imagery**, failure to identify navigational hazards, or incorrect assessment of discrepancies between the ENC and **radar imagery**.

**Green radar imagery**

![Green Overlay](images/Overlay_Green.png)

**Yellow radar imagery**

![Yellow Overlay](images/Overlay_Yellow.png)

**Red radar imagery**

![Red Overlay](images/Overlay_Red.png)
<br><br>

#### Radar Overlay Warnings:

| **Text** | **Category** | **Condition** | **Recommendations** |
|-----------|----------------|-------------|------------------|
| No radar video signal: \<source name\> | Warning | When radar video signal data stops being received | check radar (radar processor) power-on status, cable connections, video channel settings |
| No trigger signal: \<source name\> | Warning | When trigger signal data stops being received | check connection of corresponding signals from the radar to the radar processor |
| No heading signal: \<source name\> | Warning | When heading signal data stops being received | check heading sensor status, check heading sensor connection (settings) to ECDIS and to the Radar |
| No antenna bearing signal: \<source name\> | Warning | When antenna bearing signal data stops being received | check antenna bearing data reception in the diagnostics window |
| No connection to RP: \<source name\> | Warning | No connection to the radar processor | check network settings, physical connection, radar processor power supply |

```{important}
Radar imagery overlay on the ENC requires heading, antenna bearing, trigger, and position data.

If transmission of any of these navigation parameters is absent, radar imagery overlay is not possible and will be disabled until the fault is corrected.
```
