identify_METAR_token: Identify type of a METAR token
In derry-dev/metar: Process METAR string into structured data

Description Usage Arguments Details Examples

View source: R/functions.R

Determines the type of information conveyed by a particular METAR token.

1	identify_METAR_token(i)

`i`	A string token, found separated by spaces in a METAR string. E.g. a METAR reading of `METAR ZZZZ 010825Z 18010KT CAVOK 05/02 Q1000 NOSIG` will have tokens "`METAR`", "`ZZZZ`", "`010825Z`", and etc.

The METAR token i is distinguished via regular expression, and returns one of the following:

metar: Token METAR which usually occur at the start of a reading.
apt: Airport ICAO code.
time: Time information containing day, hour and minutes in Zulu/GMT.
wind: Wind information containing heading (degrees or VRB), wind speed, optional gusting wind speed and wind speed units (either knots KT, metres per second MPS or kilometres per hour KPH).
wind_vdir: Wind direction information containing two headings indicating range of varying wind direction.
vsby: Prevailing visibility in metres.
dvsby: Prevailing visibility in metres with directional indicator.
rvr: Runway visual range information containing runway, visibility range in metres and trend visual range change (increasing U, decreasing D or no change N).
wx: Weather code.
cloud: Cloud information containing amount (few FEW, scattered SCT, broken BKN or overcast OVC) and height of cloud base in hundreds of feet.
cloud_conv: Cloud information containing amount (few FEW, scattered SCT, broken BKN or overcast OVC), height of cloud base in hundreds of feet, and significant convective cloud (Cumulonimbus CB or Towering Cumulus TCU).
cloud_alt: Alternative cloud information such as "ceiling and visibility OK" CAVOK or no sigificant cloud NSC.
vv: Vertical visibility in hundreds of feet, this is found after a cloud token when sky is obscured.
tempdew: Air temperature and dew point in whole degrees Celsius.
qnh: QNH in millibar/hectopascal.
trend: Trend forecasts starting token, this is either becoming BECMG or temporary TEMPO. Note that time group tokens preceding the trend starting token cannot be recognised by identify_METAR_token
windshear: Wind shear starting token WS. Note that wind shear is currently unsupported.
unknown: When identify_METAR_token fails to recognise token argument.