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Map a plan position indicator (ppi) on a map

Source: R/map.R
map.Rd

Plots a plan position indicator (ppi) on a base layer

Usage

map(x, ...)

# S3 method for class 'ppi'
map(
  x,
  map = "cartolight",
  param,
  alpha = 0.7,
  xlim,
  ylim,
  zlim = c(-20, 20),
  ratio,
  radar_size = 3,
  radar_color = "#202020",
  n_color = 1000,
  palette = NA,
  zoomin = -2,
  cachedir = tools::R_user_dir("bioRad"),
  ...
)

Arguments

x

A ppi object.

...

Arguments passed to ggplot2::ggplot().

map

Basemap to use, one of rosm::osm.types()

param

Character. Scan parameter to plot, e.g. DBZH or VRADH. See summary.param() for commonly available parameters.

alpha

Numeric. Transparency of the data, value between 0 and 1.

xlim

Numeric vector of length 2. Range of x values (degrees longitude) to plot.

ylim

Numeric vector of length 2. Range of y values (degrees latitude) to plot.

zlim

Numeric vector of length 2. The range of values to plot.

ratio

Numeric. Aspect ratio between x and y scale, by default \(1/cos(latitude radar * pi/180)\).

radar_size

Numeric. Size of the symbol indicating the radar position. Use NULL if you do not want to plot the radar point. This might be useful the radar is outside the range of data.

radar_color

Character. Color of the symbol indicating the radar position.

n_color

Numeric. Number of colors (>=1) to use in the palette.

palette

Character vector. Hexadecimal color values defining the plot color scale, e.g. output from viridisLite::viridis().

zoomin

Numeric. Maps to ggspatial::annotation_map_tile()

cachedir

Character. Maps to ggspatial::annotation_map_tile(), defaults to tools::R_user_dir("bioRad")

Value

A ggplot object

Details

Available scan parameters for mapping can by printed to screen by summary(x). Commonly available parameters are:

  • DBZH, DBZ: (Logged) reflectivity factor (dBZ)

  • TH, T: (Logged) uncorrected reflectivity factor (dBZ)

  • VRADH, VRAD: Radial velocity (m/s). Radial velocities towards the radar are negative, while radial velocities away from the radar are positive

  • RHOHV: Correlation coefficient (unitless) Correlation between vertically polarized and horizontally polarized reflectivity factor

  • PHIDP: Differential phase (degrees)

  • ZDR: (Logged) differential reflectivity (dB) The scan parameters are named according to the OPERA data information model (ODIM), see Table 16 in the ODIM specification.

Methods (by class)

  • map(ppi): Plot a ppi object on a map.

See also

Other ppi functions: [.ppi(), plot.ppi(), summary.ppi()

Examples

# Project a scan as a ppi
ppi <- project_as_ppi(example_scan)
# \donttest{
if (all(sapply(c("ggspatial","prettymapr", "rosm"), requireNamespace, quietly = TRUE))) {
# Choose a basemap
basemap <- rosm::osm.types()[1]

# Map the radial velocity of the ppi onto the basemap
map(ppi, map = basemap, param = "VRADH")

# Extend the plotting range of velocities, from -50 to 50 m/s
map(ppi, map = basemap, param = "VRADH", zlim = c(-50, 50))

# Map the reflectivity
map(ppi, map = basemap, param = "DBZH")

# Change the color palette to Viridis colors
map(ppi, map = basemap, param = "DBZH", palette = viridis::viridis(100), zlim=c(-10,10))

# Give the data more transparency
map(ppi, map = basemap, param = "DBZH", alpha = 0.3)

# Change the appearance of the symbol indicating the radar location
map(ppi, map = basemap, radar_size = 5, radar_color = "blue")

# Crop the map
map(ppi, map = basemap, xlim = c(12.4, 13.2), ylim = c(56, 56.5))
}
#> Zoom: 9
#> Fetching 4 missing tiles
#> 
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#> ...complete!

# }