Overview

A Speed Range Event identifies AIS-transmitting vessels traveling within a specific range of speed (e.g., 1-4 knots). 

These events can only be created for Areas of Interest in the Skylight web platform. The speed range events must be configured by the user for each Area of Interest. Speed Range events will become possible from the time of configuration; they are not historical.

Configuration requires setting rules about the speed a vessel must travel over a specific distance or period of time. These events can be used as a backup or proxy for vessel behaviors (fishing, rendezvous, etc.) or other speed related regulations (measures to protect whales).

Algorithm

The algorithm to detect vessels traveling within certain speeds is configured by the user. There are two approaches, by time or distance.

The first step is to determine the speed of interest (e.g., certain fishing behaviors may occur between 1-4 knots.). The second step is to determine the duration of the observed speed 

• By distance - nautical miles (nm), kilometers (km) or miles (mi). 
• By time - hours or minutes

Event Details

Standard information

Vessels' information - name, MMSI, Type based on AIS data, IMO, Length based on AIS data

Date and time of the event

Location (lat/lon)

Event history - number of times Skylight has detected this behavior from this vessel

Additional information

Defined Speed Range - The user-configured speed range and duration (time/distance) (e.g., 2-5 knots for at least 1nm)

Average Speed Range - The average speed of vessel, and how long the vessel was observed, within the specified range of speed (e.g., 2.2 knots for 1 hour, 22 minutes)

Area - The name of the relevant Area of Interest

Latency

Speed range events are computed in real time and may be available in just a few minutes following the time conditions are met (i.e., a vessel observed traveling within a speed range for a certain duration) depending on AIS signal. 

Average latency is 1 hour.