Enrich positions

The Enrich positions flow analyzes the VMS route of vessels and computes a number of features which are then inserted in additionnal computed columns of the positions table :

  • is_at_port : a boolean which is true if the position is in one of the anchorage H3 cells and false otherwise

  • distance, time and average speed from the previous emitted position

  • total time of continuous emission since the last exit of a harbour

  • is_fishing : a boolean which is true if the fishing activity is detected and false otherwise (see below)

It is scheduled to run every minute.

Fishing detection

Based on several years of VMS and logbook data, it has been observed that fishing activity can be detected on a VMS track with great accuracy, for any type of fishing gear, using the following criteria :

  • the vessel is at sea (i.e. outside of a port) for > 1 hour

  • the vessel’s average speed (i.e. the distance between two VMS positions divided by the time between the two positions) remains between 0.0025 and 5.5 knots twice in a row

Map with VMS tracks colored in green where fishing activity is detected

VMS tracks colored in green where fishing activity is detected

Note : the 0.0025 knots lower bound is useful to filter out vessels at anchor