CALCULATION OF PSDF OF SCINTILLATION FOR 7 MU-M BAND TDL BEAM AROUND WATER-VAPOR LINE

We derive the temporal PSDFs theoretically by combining Filho's tempor al PSDF and parameters of the absorption line stated in the optical li ne parameter compilation, and explain some interesting phenomena of th e experimental temporal PSDFs by using the derived theoretical tempora l PSDF, especially enhancement in the lower frequency region. The theo retical PSDFs tell us that the increasing of the absorption causes the lower corner frequency to shift to the higher frequency. Besides, the magnitude shifting of the lower corner frequency depends on the value of the absorption coefficient as well as the concentration of the abs orbing medium. On the other hand, under the same atmospheric condition s, the profiles of the theoretical PSDFs for different wavelengths ove rlap each other in the higher frequency region, and the higher corner frequency has no relationship to the absorption. We show that the abso rption affects the lower frequency region of the PSDFs of the infrared light, while the higher frequency regions of the PSDFs are affected b y the refraction of the light like visible light waves.