There are tens of mirrors thousands of kilometers above the Earth. These mirrors, which transmit any data received from one place to another, act like the nameless hero that no one has seen. These mirrors, which are the main actors of many tasks put at the service of people, are silent, they only do their duty. Even if you lift your head, you cannot see them; but they are actually where you are looking. They circle over our heads like birds of prey. As you guessed, we’re talking about satellites.
We live in the space age. The world is no longer enough for people. While these were being put forward as to whether there is life on the Moon or water on Mars, space tourism gradually began to come to the fore. As a matter of fact, the duties of satellites seem to increase even more. According to the increasing supply-demand balance, satellite systems and space exploration also differ. Satellites launched from space stations are also increasing. Each country seeks to have a say in the world with its own satellite. We live in a time when even military movements are watched from space. Giant eyes that can read the license plates of vehicles from space, and large ears that follow the sounds can also be effective in determining the policies of states.
After briefly emphasizing the importance of satellite systems, let’s take a closer look at the issue. When you hear the phrase ‘satellite’, don’t think of an instrument used only for watching television. Satellite systems that have spread like ivy in the last 10-15 years are not just the simple devices we use for satellite channels. But first, let’s talk about the systems of satellite channels that come into play with digital broadcasting.
Satellites and Television Broadcasts
Satellites used to monitor satellite channels are located at an altitude of about 35,784 kilometers from Earth. They serve to receive the broadcast signals sent from the Earth and deliver them to the desired coverage area. It looks like a simple mirror task. Satellites orbit the Earth and rotate simultaneously with the Earth. A gas located on them acts as a thrust. Giant panels extending to both sides also provide solar energy. The average lifetime of satellites is 12 years. In other words, when their gas runs out, their lifespan also ends. A satellite used for 12 years is now replaced with new ones because it uses an old technology. Refilling the gas of expired satellites and using an old technology for another 12 years does not seem logical in the current conjuncture. That ‘gas regeneration‘ is not a process that cannot be done…
Let’s come to television broadcasts; The pan-like devices, called ‘dish antennas’, located at the signal transmitter and receiver points, are an indispensable factor for the exchange of television broadcasts. Thanks to these satellites and dish antennas, it is possible to watch and listen to all kinds of television or radio broadcasts even in the roughest terrains, provided that the satellite can see the point where it is located. Intermediary institutions are needed to receive broadcasts from different satellites. For example, a standard satellite antenna is not enough to watch a television channel in the United States from Erzurum. Huge antennas that receive this broadcast from other satellites are needed. By subscribing to digital broadcasting companies that have systems that can receive this broadcast, we can find the opportunity to watch broadcasts in different countries or on satellites that we cannot reach from our location.
In order to receive satellite broadcasts, a signal receiving device called a ‘ receiver ‘ is also needed, apart from a dish antenna. At first, receivers, which were the size of a laptop, have now become as small as a hand. New generation televisions, on the other hand, have satellite receivers integrated into the televisions.
Meteorology Satellites: We take precautions when we watch an approaching storm or a downpour that will start 2-3 hours later in weather programs. We are also amazed when the rain begins to fall at the appointed hour; ‘How do they know?’ we ask. Actually, there is nothing to be surprised about. An eye watching the movements of the clouds can give us all kinds of tips. Meteorological satellites are satellites used for both military and civil purposes, which inform any upcoming weather movements. There are two different Meteorology satellites in orbit up to 1500 kilometers from Earth and in geosynchronous orbit at a distance of 35,784 kilometers. Precise forecasts of regional weather conditions can be made from satellites in close orbit.
Space Research Satellites: There are 7 different space research satellites in different orbits for space exploration. These; They are named as Astronomy satellites, Geodesy satellites, Magnetosphere satellites, Meteor Observation satellites, Ionosphere satellites, Sun Observation satellites, Atmosphere satellites. The specified satellites are important parts of space exploration.
We can collect the orbits of the satellites under 6 headings. These orbits; It is called Geosynchronous, Sun Synchronous, Polar, Meo, Leo, Heo .
The only orbit that moves simultaneously with the earth and whose position remains constant is the geosynchronous orbit. It is 35,784 kilometers from the earth. It is also called Satellite Orbit or Clarke Orbit. It rotates in the same direction as the Earth, located at the latitude of the Equator. Since it moves with the earth, it is the most suitable orbit for the use of communication satellites.