Parameters 

Description 

fn [string] 

Filename to be read 

fmt [scalar] 

Identifier for the data format. fmt=1 is a CSV file provided by the 14th weather squadron with historical METAR data. fmt=2 (most common) is a text file with data downloaded from https://climate.af.mil/WebObs/index.jsp (requires CAC) OR one-minute observation data. 

rowIndex [varies] 

Identifier for the data to extract. If a scalar it is the row number (not counting any header rows), if a date (datetime or date vector), will return data from the row with the closest date/time match. If rowIndex is a date vector, it is assumed to be in UTC time. Pass [] to read all data from the file. 

Return Values 

Description 

metData [struct] 

Structure with fields 

DATE [datetime] 

Date of observation time (Matlab datetime object) 

site [string] 

Site code 

lat [scalar] 

Site latitude (deg decimal) 

lon [scalar] 

Site longitude (deg decimal) 

alt [scalar] 

Site altitude (m MSL) 

temp [scalar] 

Temperature (K) 

dp [scalar] 

Dewpoint (K) 

press [scalar] 

Pressure (Pa) 

rh [scalar] 

Relative humidity (%) 

windSpeed [scalar] 

Wind speed (m/s) 

windDir [scalar] 

Wind direction (deg) 

vis [scalar] 

Visibility (m) 

cloudCond [matrix] 

Observed cloud conditions in a 3x2 matrix. Column 1 holds the fractional cloud coverages at each layer, column 2 holds the cloud layer altitude in ft AGL. 

surfCn2 [scalar] 

Surface Cn2 - NaN if fmt=1 or 2 (m^{-2/3}) 

METAR [string] 

Raw string data from the METAR file