Impact of Water Vapor Attenuation on Low Elevation SatCom Links

The water vapor absorption effect cannot be neglected in satellite communication (SatCom) systems operating at higher frequency bands (e.g. W band). It becomes even more significant when it comes to very low elevation angles, such as those characterizing GEO satellites with ground stations at high latitudes, or MEO/LEO satellites. This paper presents some preliminary results on the impact of water vapor attenuation AV at different elevation angles, as well as on scaling AV from zenithal pointing to low elevation angles. The results, obtained from an extensive set of large water vapor content maps, show that the customary cosecant scaling approach is accurate down to 5°. Finally, some preliminary results on the impact of AV on a link to a MEO satellite are also shown.