downloadMarCadAIS {PAMscapes}

Download AIS Data from Marine Cadastre

Description

Downloads daily AIS files from https://marinecadastre.gov/ais/ covering the date range present in input data

Usage

downloadMarCadAIS(x, outDir, overwrite = FALSE, unzip = TRUE, verbose = TRUE)

Arguments

x

a dataframe with column UTC in POSIXct format

outDir

directory to save the downloaded files

overwrite

logical flag to overwrite existing data. Recommended to be FALSE to avoid re-downloading large files unnecessarily

unzip

logical flag to unzip downloaded files. Original downloads from Marine Cadastre come as large .zip

verbose

logical flag to print messages about download progress

Value

a vector of the paths to the downloaded .zip files, any days that were unable to download will be NA

Author(s)

Taiki Sakai [e-mail]

Examples

# note this example downloads a ~500MB file

gps <- data.frame(Latitude=c(33.2, 33.5,33.6),
                  Longitude=c(-118.1, -118.4, -119),
                  UTC=as.POSIXct(
                    c('2022-04-28 05:00:00',
                      '2022-04-28 10:00:00',
                      '2022-04-28 20:00:00'),
                    tz='UTC'))
tempDir <- tempdir()
marcadFiles <- downloadMarCadAIS(gps, outDir=tempDir)