parse_METAR: Decode and tabulate METAR data
In derry-dev/metar: Process METAR string into structured data

Description Usage Arguments Details Examples

View source: R/functions.R

Decodes and returns a table of processed METAR data allowing for easier analysis.

1	parse_METAR(metar, out_format = "data.frame")

`metar`	A single METAR string or a vector containing METAR strings.
`out_format`	One of the following: list returns a list with data from each METAR string as a separate list element, data.frame returns the data in a data.frame with one row per METAR reading, data.table (requires data.table package) returns the data in a data.table with one row per METAR reading.

The output data will contain the following columns or named sublist elements:

apt: Airport ICAO code (string).
day: Day of METAR reading (numeric).
hour: Hour of METAR reading (numeric).
min: Minute of METAR reading (numeric).
wind_hdg: Wind heading in degrees (numeric).
wind_vrb: Boolean indicating variable wind heading (boolean).
wind_speed: Wind speed (numeric).
wind_gust: Gusting wind speed (numeric).
wind_unit: Unit of wind/gust speed (string).
wind_hdg_min: Minimum value of variable wind heading range (numeric), available when wind_vrb is TRUE
wind_hdg_max: Maximum value of variable wind heading range (numeric), available when wind_vrb is TRUE
vsby_dist: Distance of prevailing visibility (numeric).
vsby_dir_dist_*: Distance of corresponding prevailing visibility in a certain direction (numeric).
vsby_dir_hdg_*: Direction of corresponding prevailing visibility in a certain direction (string).
rvr_rwy_*: Runway of corresponding runway visual range (string).
rvr_code_*: Code indicating whether RVR is greater than measurable maximum value (P) or is less than measurable minimum value (M) of corresponding runway visual range (string).
rvr_vis_*: Visibility distance of corresponding runway visual range (string).
rvr_trend_*: Trend of visibility distance change of corresponding runway visual range (string), this is either increasing U, decreasing D or no change N.
wx: All weather codes (string).
skyc_*: Cloud amount of corresponding cloud layer (string), this is either few FEW, scattered SCT, broken BKN, overcast OVC or code indicating "ceiling and visibility OK" CAVOK or no sigificant cloud NSC.
skyl_*: Cloud height in feet of corresponding cloud layer (numeric).
skyx_*: Extra code indicating significant convective cloud of corresponding cloud layer (string), this is either cumulonimbus CB or towering cumulus TCU.
vv: Vertical visibility in feet (numeric) when sky is obscured.
tmp: Air temperature in degrees Celsius (numeric).
dwp: Dew point in degrees Celsius (numeric).
qnh: QNH in millibar/hectopascal (numeric).
trend: Trend forecast (string).
ws: Currently unsupported.
unhandled: Contains tokens for which a type has been identified, but was not decoded for some reason (string).
unknown: Contains tokens for which a type has not been identified (string).

x <- c(
  "METAR ZZZZ 010825Z 18010KT CAVOK 05/02 Q1000 NOSIG",
  "METAR ZZZZ 101455Z 09008KT 050V130 9999 FEW030 09/03 Q1027 NOSIG",
  "METAR ZZZZ 200525Z VRB02KT 9999 R17L/1200D FEW040 15/14 Q1024 NOSIG"
)

parse_METAR(x[1], out_format = "list")
parse_METAR(x) # Returns data.frame by default
parse_METAR(x, out_format = "data.table")