Estimate vessel characteristics

Estimates the most likely vessel characteristics for each mmsi from AIS messages, including ship type, length, width, draught, IMO number, and vessel name. Estimates are based on the most frequent values, giving greater weight to records with more complete information.

Usage

AISinfos(
  ais_data,
  threshold_length = 475,
  threshold_draught = 30,
  threshold_width = 75,
  weight_complete_data = 10
)

Arguments

ais_data

AIS data frame containing the columns mmsi, shiptype, length, width, draught, imo, and name. Another vessel identifier may be used if the column is named mmsi.

threshold_length

Maximum valid vessel length (m). Larger values are set to NA.

threshold_draught

Maximum valid draught (m). Larger values are set to NA.

threshold_width

Maximum valid vessel width (m). Larger values are set to NA.

weight_complete_data

Weight assigned to records containing both vessel length and ship type.

Value

A list containing:

• estimated_values: Estimated vessel characteristics for each mmsi.

• summary: Summary statistics for each mmsi, including:

  • Number of AIS positions.

  • Number of non-missing values for length, shiptype, width, draught, imo, and name.

  • All valid values observed for each characteristic.

  • The most likely value for each characteristic.

Examples

if (FALSE) { # \dontrun{
library(AISanalyze)
data("ais")

out <- AISinfos(ais_data = ais)} # }