AIS - Shipping Traffic - Average weekly density of vessel types

A combined version of the annual AIS average weekly density datasets created by the Marine Management Organisation (MMO), clipped to northern UK, at a 2km grid resolution. AIS datasets were sampled from the first seven days of each month, commencing with January, at monthly intervals. The total value for all 12 weeks was divided by 12 to determine the weekly average, therefore decimal values may occur for certain cells. The weekly average was also multiplied by 52 to provide the estimated annual average. The field headings in the attribute table are: ave_stg_0 - Unknown Vessels; ave_stg_1 - Non-Port service craft; ave_stg_2 - Port service craft; ave_stg_3 - Vessels engaged in dredging or underwater operations; ave_stg_4 - High Speed Craft; ave_stg_5 - Military or Law enforcement; ave_stg_6 - Passenger; ave_stg_7 - Cargo; ave_stg_8 - Tankers; ave_stg_9 - Fishing vessels; ave_stg_10 - Recreational vessels; Weekly_Ave - Weekly Average Density; Yearly_Ave - Estimated annual density.

It should be noted that in the underlying data set (if attributes are examined) vessel categories might not always be as expected. For example, ferries may sometimes be classified as 'Passenger' and at other times as 'Cargo' vessels depending on the exact nature of the vessel on a particular route.