How are geostationary satellites used for communication?
They are placed so that the orbitals speed will be same with Earth.
So they remain above same place on earth 3 Such satellites can cover the whole earth for communication..THey can be used as relay station for TV, and other communications covering whole world..
Picture credit slideshare.net.
Relative to the Earth, geostationary satellites remain stationary ( at rest ), vertically above a point on the Earth's surface.
Geostationary satellites have period of rotation about Earth's center
as 1 day. They are placed at an altitude of about 35800 km, The
orbit direction relative to the Earth synchronizes with that of the
Earth's day/night spin. They remain stationary ( at rest, relative to
the Earth, ) vertically above a point on the Earth's surface.
They can receive and transmit signals from a part of the the Earth's
surface in the form of a spherical cap that is symmetrical about their
For the altitude 35800 km, the spherical cap subtends a conical
So, the proportion of the Earth's surface covered by one such
Tesselation (dividing the surface into caps without gaps) is not
To cover the entire globe, overlapping cannot be avoided. .