scope:

This Recommendation provides methods to estimate the attenuation of atmospheric gases on terrestrial and slant paths using:

a) an estimate of gaseous attenuation computed by summation of individual absorption lines that is valid for the frequency range 1-1 000 GHz; and

b) a simplified approximate method to estimate gaseous attenuation that is applicable in the frequency range 1-350 GHz.

The ITU Radiocommunication Assembly,

considering

a) the necessity of estimating the attenuation by atmospheric gases on terrestrial and slant paths,

recommends

1 that, for general application, the procedures in Annex 1 be used to calculate gaseous attenuation at frequencies up to 1 000 GHz;

2 that, for approximate estimates of gaseous attenuation in the frequency range 1 to 350 GHz, the computationally less intensive procedure given in Annex 2 be used.