National Geographic Channel Gets GPS Wrong?
I was catching up on some DVR recordings recently and one of the shows I was watching started talking about GPS. The show I was watching was titled Known Universe on the National Geographic Channel. Specifically, it was the episode titled “The Fastest”. The show was focusing on things that happen (literally) at the speed of light, and they started to describe how GPS works. They said this:
The signal from the GPS device travels at the speed of light to a satellite in space. The satellite measures how long the signal took to reach it to determine the distance.
I know quite a bit about GPS, but I’ve never proclaimed to be an expert on all of the involved physics. But I do know the description above sure sounds backwards to me! I think it would have been more accurate to say it this way:
The signal from the
satellitestravels at the speed of light to a
on earth. The
GPS receivermeasures how long the signal took to reach it to determine the distance.
While the TV show wasn’t geared towards kids, the following video was and it does a much better (and more accurate) job of describing how GPS works.