Table 2: Summary table of the main features of wet mapping functions.

Code Reference Impute parameters εmin˚
SA Saastamoinen (1987) z, T0, eo 10˚
HO Hopfield (1971) ε, T0, eo **
BL Black (1978) ε, T0, eo, r
CH Chao (1972) ε 10˚
IF Ifadis (1986) ε, t0, eo, P0
HE Herring (1992) ε, t0, φ, Ho
NI Niell (1993) ε, φ
MO Moffett (1973) ε
B & E Black and Eisner (1984) ε
UNBabc Gue J. and Langley R. (2003), ε, φ, H0

where: φ is the station latitude, H is the station height, r is the effective radius of the station, T0 is the temperature at site in K˚, t0 is the temperature at site in ˚C, e0 is the partial water vapor pressure in (mb), z is the zenith angle and ε is the elevation angle. ** Means that: not specified or valid for any elevation angle.