Depends on how long the signal lasts. If it's continuous, there's no way to take it with a single transmitter. Astronomers can detect the apparent motion of sta

Depends on how long the signal lasts. If it's continuous, there's no way to take it with a single transmitter. Astronomers can detect the apparent motion of stars caused by the earth's orbit, and use those measurements to triangulate the distance to stars, even though the stars are many light years away. A single transmitter on a probe near our solar system would be very obvious.