## Purpose

A pelorus is not a sensor connected to ECDIS; rather, it represents the installation point of optical bearing sights.

Bearing stations are necessary for performing {doc}`manual observations </sections/instruments/manual-observations/index>` using visual methods.

When processing results of bearing visual landmarks, the sensor used for the bearing must be specified.

Measurement results are recorded in the {doc}`electronic log book </sections/navigational-log/manual-observations/index>`, indicating the sensor used for the measurement.

```{danger}
With significant vessel dimensions and peloruses spread across the sides or along the side, failure to account for pelorus positions relative to **CCRP (Center of Common Reference Point)** or an error in pelorus positioning in the ship's coordinate system may result in a navigation miss and, subsequently, a navigation error.
```

## Setup

When configuring a pelorus, the following requirements must be observed:

- **Quantity**: The number of peloruses created in ECDIS is unlimited but must correspond to the actual vessel equipment.
- **Name**: The pelorus name must indicate the installation location and exclude misinterpretation of the device used for measurements.
- **Coordinates**: Pelorus installation coordinates must be specified with an accuracy of 0.1 meter relative to CCRP.

![Pelorus settings](images/Pelorus_1.png)

```{important}
Accuracy in specifying pelorus coordinates is critical for observation correctness. With significant vessel dimensions, a positioning error may result in a miss in observation calculation.
```

![Pelorus configuration parameters](images/Pelorus_2.png)
