Clear Sky – Definition and Pronunciation
What is Clear Sky?
Clear sky is a term describing the weather conditions encountered at the terrestrial end of an earth-space path of a satellite communication link. It is used to describe the condition where the attenuation of radio waves caused by precipitation (rain, snow, sleet, dew, etc.) is lowest (i. e., cloud-free sky and good visibility).
Examples of Clear Sky
While the amplitude of these grating lobes when operating at the highest clear sky EIRP is as much as 22 dB above the 25,138 off-axis EIRP density mask, the location of these lobes with respect to the GSO arc is such that the lobes do not intersect the GSO arc except when the aircraft is located in a limited number of geographic areas.
From “Aeronautical Mobility Services”.
All HTSs use the DVB-S2 standard, and DVB-S2X will likely be used in the future. As we saw elsewhere in this category, ACM reduces the information rate during rain fades and resumes at the clear sky level after the rain fades (the range of C/N margin, when comparing 16 PSK clear sky to 1/2 BPSK, is approximately 12 dB).
From “High Throughput Satellites (HTS) and KA/KU Spot Beam Technologies”.
C-band receive-dishes for broadcast-quality video reception are typically 3,8–4,5 m in diameter. The size is selected to optimize reception under normal (clear sky) or medium-to-severe rain conditions; however, smaller antennas of 1,5–2,4 m can also be used, depending on the intended application, service availability goals, and satellite footprint.
From “Exploring the Future of Satellites”.
Pronunciation of Clear Sky
