### ARPA

**ARPA** — Automatic Radar Plotting Aid

**ARPA (Automatic Radar Plotting Aid)** is a sensor relative to ECDIS.

It performs the following tasks:
 - target detection;
 - calculation of target motion parameters;
 - target tracking;
 - calculation of passing conditions;
 - simulation of passing maneuvers;
 - target association;

A radar can be connected to ECDIS as ARPA.

```{important}
ECDIS does not contain a built-in ARPA system. ECDIS only receives and displays tracked target forms from an external ARPA via the NMEA protocol. All target detection, tracking, and motion prediction functions are performed by ARPA.
```

```{include} arpa-setup/index.md
:relative-images:
```

```{include} arpa-features/index.md
:relative-images:
```
