Correct wind data for ship motion

This example shows how to calculate course and speed over ground of the ship and use it to correct the wind speed and direction data.

from arm_test_data import DATASETS
import xarray as xr

import act

# Read in the navigation data, mainly for the lat/lon
filename_nav = DATASETS.fetch('marnavM1.a1.20180201.000000.nc')
nav_ds = act.io.arm.read_arm_netcdf(filename_nav)

# Calculate course and speed over ground from the NAV
# lat and lon data
nav_ds = act.utils.ship_utils.calc_cog_sog(nav_ds)

# Read in the data containing the wind speed and direction
filename_aosmet = DATASETS.fetch('maraosmetM1.a1.20180201.000000.nc')
aosmet_ds = act.io.arm.read_arm_netcdf(filename_aosmet)

# Merge the navigation and wind data together
# This have been previously resampled to 1-minute data
ds = xr.merge([nav_ds, aosmet_ds], compat='override')

# Call the correction for the winds.  Note, that this only
# corrects for ship course and speed, not roll and pitch.
ds = act.corrections.ship.correct_wind(ds)

nav_ds.close()
aosmet_ds.close()
ds.close()