alt Hacker NewsI am curious, how are we communicating with it? like how do we know where it is right now, and how are we sending signals to communicate with it? won't our signal affected by noise or the like. When it is this far, how are accurately sending our signals to it.
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JacobThreeThree • today at 6:54 AM
Per Wikipedia:
It has a 3.7-meter (12 ft) diameter high-gain Cassegrain antenna to send and receive radio waves via the three Deep Space Network stations on the Earth. The spacecraft normally transmits data to Earth over Deep Space Network Channel 18, using a frequency of either 2.3 GHz or 8.4 GHz, while signals from Earth to Voyager are transmitted at 2.1 GHz.
We know where it is right now, because we know which way it's going, how fast and that it isn't currently thrusting anywhere. its just going in a (straight?) line, so it's pretty easy to keep track of.
You can measure the speed of something towards/away from you by measuring the doppler shift of the signal (how much the frequency is increased or decreased compared to the expected frequency), and since the radio receivers will have to be very precisely pointed to get a good signal, you can also probably fine tune any estimates of position by wiggling the receivers around a little bit until you get the best signal. The signals are definitely getting degraded by noise etc, since it's so far away. That's why the communication speed is so slow, so they can make sure they got one bit before getting the next one. Some more mathsy details here https://space.stackexchange.com/questions/24338/how-to-calcu...
But by having a very big antenna, and knowing exactly what you're looking for and where, it can help to filter out all the noise and get out the proper data