You know what a satellite is. So what do we use them for? Today’s satellites can do so many amazing things that it is almost impossible to list. In this book, we will touch upon some of the most common tasks to give you a good understanding of what satellites are used for and how they affect our everyday lives.
(On the opposite page of this text is a picture of the Earth with satellites with four blue panels jutting out from around it flying past it and almost off the page.)
Data, pictures, words, and music are sent up to a satellite and converted to an invisible beam of energy. This is called a broadcast signal. When the signal reaches space it is grabbed by the satellite and sent back down to its destination. There the invisible signal is converted back to data, pictures, words, or music. Sometimes the process involves digital signals, which are very complex (the signal is converted into numbers). Many of the satellites in orbit have powerful computers on board to handle digital signals. What does this mean? Well, digital signals are much clearer, sharper, and more colorful than broadcast signals. They carry more information and take less time to transmit and convert.
(The opposite page displays a picture of the Earth with a signal source indicated on the mid-right of the planet beaming a green line up to a blue satellite in orbit above the Earth which, in turn, is beaming a green line down to a signal destination on the mid-left side of the Earth)
Whenever you watch a television show on one of your favorite channels, do you ever wonder how your TV is able to receive the program? Well, whether you use cable, dish, or antenna to receive your programs, they are all routed through a satellite. Let’s say you are watching a live reality show made in a Hollywood studio. To get the signal to you, the studio will broadcast the signal up to the satellite. This is called an “uplink.” The satellite will then rebroadcast the signal down to your local station which is sent to your TV. This is called a “downlink.”
(The image on the opposite page from this text depicts a TV camera representing a TV studio beaming rainbow colored signal line up to the satellite at the top of the page which, in turn, is beaming a rainbow colored signal down to a TV set showing a picture of a happy little boy bouncing around.)
There are satellites responsible for finding and tracking ships, planes, cars, people, plus many other things. These are called Global Positioning System (GPS) satellites. They receive a data signal from a small device and send a signal back showing exactly where you are on an electronic map. GPS devices help police find people who are lost or in danger. They keep ships and planes on course to their destinations. They are very important to the military because they help officers keep track of their forces. These devices are helping people everywhere. You may have one in your car right now!
(The image on the opposite page of this text has a banner at the top which says “GPS satellite tracking an airliner over the USA.” There is a satellite in the upper right-hand corner tracking an airplane with a yellow beam over a green, yellow and red depiction of the USA. The same satellite is sending a blue beam signal to a hand holding a GPS device showing the tracking of the airplane.)
We rely on satellites to help us track weather, especially big storms such as thunder storms, hurricanes, and tornadoes. Many satellites can take pictures to give scientists and technicians a better look at what is happening with the Earth in order to predict weather and possible disasters.
(The image above this text is of a hurricane with flashes of light coming on at various parts of the storm) If it were not for satellites, the Internet, as we know it today, would probably not exist. Every time you open a website, send an e-mail, download a file, or send a fax anywhere in the world, you are using a satellite. This is called “data transmission” because the satellite is sending, or transmitting, information or data from one computer source to another.
(The image below this text of a hand pressing a button with depiction of electricity behind it) Satellites can even explore the universe. We have sent many satellites into orbit around the Moon and several planets, such as Mars and Jupiter. These are sometimes called “probes” especially if they are sent in a path that will visit many planets in one trip. Our understanding of our solar neighbors and the surrounding universe has greatly improved thanks to the use of satellites.
(The image on the opposite page of this text is of Ollie the Satellite in outer space bouncing back and forth with the caption below him stating “Ollie Explores the Universe.”)
The following references were used in the production of this book:
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