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Vessel Tracks

Skylight provides vessel tracks to visualize vessel movements. The tracks are created from AIS data (positional points). The pattern of these tracks and associated speed can help provide analysts insight into activities of the vessel.
 
Track Availability: Vessel tracks are available for any “event” (except vessel detection without corresponding AIS data) and anywhere within a limited geographic scope.
 
Track length/visibility: The start and end of tracks is based on the date range and the visible time period of the time slider.
Tracks within the the start/end points of the visible time period are bright. While the tracks outside the visible time period are faded
Left: Colors showing vessels speeds. The tracks outside the time slider's visible time period are faded.  Right: Colors for two vessels during a rendezvous.

Track options

The track legend offers several ways to visualize tracks. 
 
  • Average Speed over ground: Colors help visualize the change in vessel speeds
  • MMSI: Separate colors for vessels based on MMSI helps to distinguish the paths of multiple vessels
  • Time of day: Color based based on time of day to determine activities by day and night 

Examples for each track option shown below.

Additional features and options

  • Connect gaps: You can connect AIS gaps of more than 2 hours. The connected gaps display as a dashed line. By default, tracks will show a gap when there has been more than 2 hours between AIS pings/transmissions.
  • Tracks: Average Speed over ground between two points. You can turn off tracks to only show positional points between each track segment.
    • Positional Points: Display the day/time, Lat, Lon coordinates, and the MMSI for the vessel
  • Speed and Course: Visible by hovering over the arrows () on a track. You can turn off the speed and course arrows from the track legend.
Left: Clicking/Hovering on a positional point reveals time, location and vessel identify. Right:Clicking/Hovering on an arrow shows the average speed of the segment and course.
 

Track color examples

The Track Legend allow you to change the color of the tracks to aid your analysis. The Track Legend is visible anytime tracks are visible on the screen (e.g., after clicking an event). 

Speed over ground

A fishing vessel appears to slow down (greens and blue colors) before moving to a new location at higher speeds (orange and red colors)

Time of day

Vessel movements by day and night

MMSI

Different colors for each vessel (by MMSI) to distinguish one vessel's tracks from another. 
 

AIS positional points and tracks

Skylight receives AIS transmissions as positional points. Skylight converts these positional points to tracks to aid in analyzing vessel movements.
 
The two images below compare individual AIS positional points to a track visualization. As the top image shows, the positional points from AIS transmissions can be irregular. It's difficult to analyze the movement of the vessel based on these points alone. 
 
The image below it show these same points represented as tracks. The tracks make it much easier to understand the movement of the vessel as well as approximate speed between two points.