history and evolution of satellite, Geostationary satellites,Satelliteorbits,DCME Data rates, noise figure M/W

Question

I want details of topic as stated above, Microwave working and noise figure

Answer 1

go here http://en.wikipedia.org/wiki/Satellites

Answer 2

Just like biological evolution, the evolution of satellites was not mindless and without purpose.

Artificial satellites was just a mildly interesting idea until some smart people after WWII realized how well you could see things on earth from space. Come the cold war and the US had to be ready to stop nuclear weapons coming from USSR. We needed lots of aerial surveillance. US built the U-2 spy plane which was temporarily beyond the reach of Soviet anti aircraft missiles until the soviets got a lucky shot and brought down a U-2 in 1960. Now the US had to have spy satellites and fast.

Communications and navigation were next two military subjects. Early Bird, I think, was the first active geostationary communications satellite. Navy developed the Transit navigational satellites then developed Timation as the prototype for GPS but the Air Force needed something to do so they got the GPS charter away from the Navy.

Noise figure and data rates are mathematically complex. Noise is the enemy of communications. Noise gets into receiving systems through cosmic background radiation (the big bang) and through antenna sidelobes which impings the earth. Everything hot (above absolute zero) gives off radiation (see Boltzmans constant). Microwave receivers unfortunately generate their own internal noise which is measured in noise figure (lower the better). Claude Shannon made major contribution to information theory when he developed relationship between noise and maximum possible data rate.

Answer 3

Go to wikipedia.com and search. You would whatever you want.