32 Suns orbiting the Earth

Submitted by marco.caparrini on June 10, 2008 - 13:22.
gps-constellation-suns_small.jpg

32 suns orbiting the Earth?

Somehow ... yes! Let's try to demonstrate it ...

Do you remember those summer holidays, many years ago, when you took these two pictures, at sunset? I'm sure you do .... But: do you remember which of the two days was the windy day?

To answer to this question you just have to carefully look at the pictures. Did you find it out? Yes! You're right! The second day was windier!

For those who are not old salts: just look at the width of the sun glint. It is larger in the right hand picture (the one of the second day): this means that the sea surface was rougher and this in turn means that there was a higher wind speed blowing over the surface!

         

Now you might ask: What does all this have to do with the initial question and the 32 suns?

Easy enough:

  • substitute the sun with a GPS satellite;

  • substitute your eyes with a special GPS receiver;

  • collect the GPS signal reflected on the water;

  • calculate the speed of the wind blowing on the surface;

  • repeat this with each of the 32 GPS satellites,

and there you are: you can estimate the wind speed over the sea surface just looking at the GPS signals that reflect on the surface. It looks handy, doesn't it? And imagine when we will have 50 suns!!!!

(Note: if you're interested in some details about the theory behind the sea wind retrieval with GPS reflections visit Starlab public library.