How do satellite dishes for tv (Direct TV for example) communicate with satellites when there so small and pointed at a small area in the sky?
In: Technology
Revcieving a signal is all about signal to noise. You can generally amplify a signal as much as you want, but it also amplifies the noise.
The dish amplifies signals only from the direction it’s pointed, and there’s not a whole lot of other transmitters in space since putting satellites up there is expensive.
Add onto that satellites are generally allowed to broadcast at a much higher wattage, than say your cell phone or wifi. Wattage limits are based on the risk of interfering with other signals. So on earth you can’t just have a 100W WiFi router because it would ruin wifi for everyone else miles around. Satellites are more well planed and regulated, and of course there’s less of them.
Add on to that that most signal loss for ground transmitters is limited due to line of sight from the curvature of the earth. Antenna towers are tall to avoid having to transmit through the ground or through buildings, trees, etc.
And add onto that that even signal loss travelling through air is fairly limited. The atmosphere is mostly all concentrated in the lowest 10 miles. Traveling through space there’s no signal loss, from traveling through vacuum.
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