Satellites are human-made bodies that orbit the earth at thousands of kilometres from the earth’s surface. Satellites are an essential part of human activities from communication, weather forecasting, and safety. Satellites are used for;
1. Communication
Communication satellites facilitate communication across the world. These satellites allow the transmission of radio, television, and telephone signals to any on the globe. Before satellites, it was difficult to transmit communication signals. The technology at the time could not send signals over long distances. Signals traveling in straight lines could not reach faraway destinations because the lines could not curve around the earth. Communication satellites leverage their orbit position to capture signals from the planet into space immediately and redirect the signals to other satellites or directly to their target destination.
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Transmission Of Television Signals
Satellites not only send television signals directly to households, but they are also the core of cable and network television. The satellites transmit signals from the central station (that generates programming) to substations that carry the signals via cable or airwaves to local households. Live events and reporting are sent from the scene to the satellite, which sends the signal to the studio. Broadcast networks across the globe depend on satellite to distribute their content to their affiliates in various regions. The affiliates then redistribute the content. Direct-to-home companies use Telesate satellites to deliver TV channels directly to their subscribers.
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Telephone Communication
Satellites form the main channel for voice communication in areas that have no phone line connection or where the lines are damaged following a disaster. Thanks to satellites, in-flight communication is possible on aircraft.
2. Remote Sensing
Remote sensing entails observing and measuring the earth’s environment from a distance. Remote sensing satellites monitor resources that are important to humans. Resource monitoring provides information and support for fisheries, forestry, agricultural produce, and management of freshwater. The satellites help with control of illegal and harmful activities like wildlife poaching, fires, illegal logging, mining that harms the environment, and illegal mining. Satellites can capture images from all over the world; they can monitor regions with harsh climate or which pose a challenge to access by land. Imaging satellites capture high-resolution data from the earth. Initially, this was a preserve of the military. However, if you have a mobile device and a robust internet connection from Earthlink, you can see your house using Google Earth.
3. Search And Rescue Operations
Search and rescue operations rely on search and rescue satellites, which provide a means for sea vessels and aircraft to communicate from remote areas. These satellites can detect and locate emergency radio beacons aboard aircraft, ships. The distress beacons can that link to search, and rescue satellites help lead rescuers accurately to the site of distress on land, sear, and even air emergency locations. Satellites can help search for an individual or people in distress in remote and dangerous places. The satellites for observing the earth can monitor potential disasters such as winds, ocean currents, oil spills, forest fires, and airborne pollution. This information is crucial in the planning and organization of emergency response and environmental clean-ups.
4. Weather Monitoring And Forecasting
Satellites collect enormous amounts of data on temperature, cloud movement, and formation, wind direction, and precipitation. Meteorologists use to analyze this to forecast weather. Satellites allow meteorologists to see the weather across the globe, which will enable them to view, monitor, and assess the effects of phenomena such as volcanic eruptions and the development of hurricanes and El Nino. Researchers use the captured data to research on climate. With imaging satellites, scientists can easily measure the changing sizes of the glacier. Often such measurements are difficult to take on the ground because of the remote nature and darkness of the polar areas.
5. Spying On Enemy Activities
Countries can spy on other countries using reconnaissance satellites. These satellites facilitate states to gather intelligence about the military activities of foreign countries. Reconnaissance satellites can detect events like missile launches and nuclear explosions and capture radio and radar transmissions over a country. Countries can also use these satellites as orbital weapons – the satellites (on low orbit) can launch warheads on ground targets. There are five types of spy satellites.
- Missile early warning which provides an early warning of an imminent attack by detecting the launching of ballistic missile
- Nuclear explosion detection detects and characterizes nuclear explosions in space.
- Photo-surveillance satellites, which capture the images of the adversary’s military activities. The photos are of two types; close-look or survey images.
- Radar imaging satellites which are used during cloud cover or at night and relay the images through radar technology
- Electronic reconnaissance satellites intercept and capture radio and radar signals when passing over a foreign country.
6. Management Of Terrestrial Activities
Imaging satellites can capture high-resolution images of almost the entire surface on earth. Satellites can detect water and minerals below the ground surface. They help monitor the movement of nutrients and contaminants from terrestrial sources into water. They can measure land and follow the erosion of topsoil from the surface of the earth. Satellites can also measure the temperature of water bodies (seas and oceans) and monitor the growth of algae in these waters. Satellites are useful in the monitoring of large scale infrastructure. For example, in the checking pipelines for leaks, satellites shorten the enormous number of hours that air-based and land-based inspections would consume.
7. Space Science
Before the advent of satellites, astrophysicists had to use ground-based telescopes to study the universe. The telescopes could only capture information from the portions of the electromagnetic spectrum, which reached the atmosphere. Today satellites provide the best means of studying the universe. Space satellite telescopes can capture data at frequencies outside the electromagnetic spectrum. It is this capacity that enables space physicists to study interesting space phenomena such as black holes, distant galaxies, and pulsars. The other advantage is that the gas molecules that constitute the atmosphere of the earth cannot cloud the vision of astronomy satellites. Therefore satellites capture clear images from the ground compared to the telescope.
8. Navigation
Navigation systems based on satellites such as GPS allow any person with a mobile receiver to establish his or her location on the earth. Modern cars have GPS locators to power built-in directional services. The same technology facilitates car-share services to locate their vehicles. The military, as well as civilians, use GPS-based systems to navigate air, land, and sea. GPS systems form useful in situations such as ship navigating challenging courses in adverse weather or crew lost in unfamiliar territory, and GPS is the only too that is available.
