If the question is regarding finding the latidude and longitude of one point on the earth, the answer is a minimum of three satellites. The method used is called triangulation. If you wish to know the altitude of the point, a minimum of four satellites are needed.
A Satellite movement behaves in two ways. Its orbit may be defined either as "geosynchronous" or "geostationary". Geosynchronous satellites move together with the Earth's own orbit, so it revolves in the same way as the earth is. Geostationary satellites remain statically in place for a certain coordinate...
Satellite communications. The use of satellites in orbit around the earth to relay data/voice from one place to the other. That's as basic of a definition as I can give you.
Inertia and gravity
That is because those satellites are in geostationary orbit, which ensures that they stay always above the same spot on the earth's surface. This is possible only if the satellite is placed in orbit at about 22,000 miles above sea level.
They have orbit maintaining rockets to keep them in place. They are traveling fast enough not to be pulled all the way back to the Earth. If they go to slow they will burn up on the way in.
Because they only need to transmit to certain parts of the planet. TV relay satellites for example - need to stay in one place to beam the pictures back to earth. If they orbited the earth, the signal would be lost as it crossed the horizon. Another example is the global GPS system. The satellites that provide the information for GPS must remain in one place - otherwise they wouldn't give accurate information to the user.
The GPS (Global Positioning System) and GLONASS satellites.
They are not needed at all, the earth would be much better place without them...
A Satellite movement behaves in two ways. Its orbit may be defined either as "geosynchronous" or "geostationary". Geosynchronous satellites move together with the Earth's own orbit, so it revolves in the same way as the earth is. Geostationary satellites remain statically in place for a certain coordinate...
by using coordinate geometry you can find the position of a place in earth by using the pictures taken by satellites.
The vast majority of satellites are in geo-stationary orbits. This means, they travel around the Earth at the same speed that the Earth rotates - making them appear in the same place. One example is the GPS satellite network. Other satellites that actually orbit around the Earth, are at a different altitude - so they would (thoretically) never collide with a stationary one. Those that are orbiting, are placed in such a way, that they also avoid each other.
Stay above the same place on Earth "forever" ... thus they stay in the same place in our sky.
There is no set inclination of a satellites orbit to the earth's equator. Once in space, the spin of the earth or where it's poles happen to be become irrelevant to the satellite. Many satellites like spy and weather satellites orbit over the two poles (north and south) while communication satellites are placed in orbit directly above the equator at a height that is synchronised with the earth's orbit. This way they stay permanently above the same place on the equator and do not APPEAR to move at all.
More details are needed to provide an answer to this question.
You mean Earth observation satellites, and the answer is near-Polar low-Earth orbits. This means that as the satellite orbits from above one pole to the other, the Earth turns beneath it, and the satellite passes over the Equator, and every other point on its orbit, at a different place on each successive orbit. In this way, after enough orbits, it can view the whole Earth. Earth observation satellites are placed in low-Earth orbit because (a) they travel faster over the ground at lower altitude and (b) being closer to the ground, their telescopes do not need to be so powerful to achieve a given spatial resolution. Military observation, or spy, satellites, are often placed in a high parking orbit until they are needed, whereupon they are placed into a highly elliptical orbit to allow them to come very close to Earth (and hence see it with great detail) over the region of interest.
Satellite communications. The use of satellites in orbit around the earth to relay data/voice from one place to the other. That's as basic of a definition as I can give you.
Inertia and gravity