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⇤ ← Revision 1 as of 2014-08-07 05:21:41
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| Most server sky customers will have small antennas, perhaps one square meter, emitting perhaps 100 mW of 70 GHz power. Through 10 dB of atmospheric and lambertian attenuation, that is 10 mW transmitted in a 25 microsteradian beam (WAG), or 400 W/sr. At 1E7 meters distance, that is 4 pW/m^2^. If one thinsat has a collecting area of 200 cm^2^, that is 8e-14 W. Assuming 600 meV per bit, 1E-19 J/bit, one thinsat can receive 800 kbps. That might be in one 1MHz wide frequency channel. | Most server sky customers will have small antennas, perhaps one square meter, emitting perhaps 100 mW of 70 GHz power. Through 10 dB of atmospheric and lambertian attenuation, that is 10 mW transmitted in a 25 microsteradian beam (WAG), or 400 W/sr. At 1E7 meters distance, that is 4 pW/m^2^. If one thinsat has a collecting area of 200 cm^2^, that is 8e-14 W. Assuming 600 meV per bit, 1E-19 J/bit, one thinsat can receive 800 kbps. That might be in one 1MHz wide frequency channel. This does not offer much angular selectivity. How can multiple thinsats combine receive signals coherently for better source selection? |
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Server Sky Uplink
Most server sky customers will have small antennas, perhaps one square meter, emitting perhaps 100 mW of 70 GHz power. Through 10 dB of atmospheric and lambertian attenuation, that is 10 mW transmitted in a 25 microsteradian beam (WAG), or 400 W/sr. At 1E7 meters distance, that is 4 pW/m2. If one thinsat has a collecting area of 200 cm2, that is 8e-14 W. Assuming 600 meV per bit, 1E-19 J/bit, one thinsat can receive 800 kbps. That might be in one 1MHz wide frequency channel.
This does not offer much angular selectivity. How can multiple thinsats combine receive signals coherently for better source selection?
MoreLater , this seems too good for one thinsat. OTOH, 70 GHz does imply a very narrow beam!