Additional columns from MarineTraffic source data are treated as date-related

[benparkergit]

Example, retaining the column "Vessel Type - Detailed" adds two columns to the output, but one would be sufficient.

# set MarineTraffic columns to merge into AIS df
# this is in addition to the Ata/atd, which is always included
MT_COLS = ["Port At Call", "Vessel Type - Detailed"]
mt_all_cols = MT_COLS + ["Ata/atd"]
# This produces:

Vessel Type - Detailed_departure
Vessel Type - Detailed_arrival

For a voyage marked as a departure, the original data is found in the _departure column.

This is not a major problem, but not ideal for a presentation for example where ships' routes are analysed by ship characteristics eg flag country, tonnage capacity.