Retrieve ERA5 variable along edge

Reads the NetCDF files and extracts the variable requested along each flight defined by the edges.

Time: linear interpolation using the resolution requested with rounding_interval
Space: nearest neighbour interpolation by default or bi-linear with pracma::interp2 if interp_spatial_linear=TRUE
Pressure/altitude: linear interpolation using the exact pressure values

Usage

edge_add_wind(
  graph,
  edge_s,
  edge_t,
  pressure = NULL,
  variable = c("u", "v"),
  rounding_interval = 60,
  interp_spatial_linear = FALSE,
  return_averaged_variable = FALSE,
  file = function(stap_id, tag_id)
    glue::glue("./data/wind/{tag_id}/{tag_id}_{stap_id}.nc"),
  quiet = FALSE
)

Arguments

graph: either a tag or a graph GeoPressureR object.
edge_s: a index of the source node of the edge. Either a vector with 3D index or a matrix of 3 columns, one for each dimension.
edge_t: a index of the target node of the edge. Either a vector with 3D index or a matrix of 3 columns, one for each dimension.
pressure: pressure measurement of the associated tag data used to estimate the pressure level (i.e., altitude) of the bird during the flights. This data.frame needs to contain date as POSIXt and value in hPa.
variable: list of the variables to extract from the ERA5 pressure level using the shortName notation: "u", "v", "t", "cc", "r", "w", "ciwc", "clwc", "q", "cswc", "d", "z", "o3", "pv", "vo".
rounding_interval: temporal resolution on which to query the variable (min). Default is to match ERA5 native resolution (1hr).
interp_spatial_linear: logical to interpolate the variable linearly over space, if FALSE takes the nearest neighbour. ERA5 native resolution is 0.25°
return_averaged_variable: logical to return the variable for each timestep or average for the entire flight.
file: absolute or relative path of the ERA5 wind data file to be downloaded. Function taking as arguments (1) the stationary period identifier and (2) the tag_id.
quiet: logical to hide messages about the progress

Value

A data.frame with columns:

stap_s id of the source/origin stationary period
stap_t id of the target/destination stationary period
s node id of the source (same as/similar to edge_s)
t node id of the target (same as/similar to edge_t)
lat_s latitude of the source
lat_t latitude of the target
lon_s longitude of the source
lon_t longitude of the target
start start datetime of the flight
end end datetime of the flight
duration flight duration
n number of flight
distance distance of the flight
bearing bearing of the flight
gs groundspeed
ws windspeed (if graph provided)

Usage

Arguments

Value

See also