The satellites are launched into the space to do a specific job , There are satellites that are launched to monitor the cloud patterns for the weather station , There are satellites that launched to send television signals for Sky TV , And every satellite has to be designed specifically to fulfill its function .
The satellites are used for many things such as the communication , the oceanography , the astronomy , the surveillance , They help many scientists get a perceptive view at all kinds of objects anywhere in the world .
The satellites send television signals directly to homes , They send the signals from a central station that generates programming to smaller stations that send the signals locally via the cables or the airwaves , The news broadcasts are sent from the field to the studio via the satellite .
The satellites provide in the flight phone communications on the airplanes , They are the main conduit of voice communication for the rural areas and the areas where the phone lines are damaged after a disaster , And they provide the primary timing source for the cell phones and the pagers .
The communications satellites have the ability to rapidly communicate between a number of widely dispersed locations , They help the big manufacturing companies and the department stores to perform inventory management , They provide the instant credit card authorization and automated teller banking services to even small towns , They pay at the pump gas at the freeway gas stations , and video conferencing for the international corporations .
The astronomy satellites are the new technology that are mounted on earth orbiting satellites or on the deep space probes , and they can give us an unobstructed view with out the earth’s atmosphere interfering . They carry the detectors to record the electromagnetic radiation at wavelengths shorter than visible light .
The satellite based navigation systems like Navstar Global Positioning Systems enable anyone with a handheld receiver to determine his location to within a few meters ,They are known colloquially as GPS .
GPS locators are increasingly included in the car direction services . GPS based systems are used by the civilians and the military for navigation on land , the sea , and the air , and they are crucial in the situations like a ship making a difficult course in a harbor in the bad weather or the troops lost in unknown regions .
There are the surveillance or spy satellites , There are four kinds of major satellites ( White 100 ) which is the most commonly used , The reconnaissance use cameras to take the pictures of a particular place from up above , And they also have a radar and infrared detectors , so , they can detect the things in the dark or the things that are covered by something or camouflage .
The reconnaissance satellites are used to spy on other countries , They provide intelligence information on the military activities of foreign countries , They can detect the missile launches or the nuclear explosions in space .
The reconnaissance satellites can pick up and record the radio and radar transmissions while passing over a country and they can be used as an orbital weapon by placing the warheads on a low orbit satellite to be launched at a ground target .
The ocean surveillance satellites are used to search for the ships or the submarines , They can spot the nuclear vessels , And new advancements may allow them to scan the depths of the ocean , Early warning and Elint satellites are primarily used by the armed forces , These basically protect the countries from the sneak attacks , and they can be used to detect if other countries are building or storing the nuclear warheads .
Elint is the basic spy satellite that picks up the radio transmissions , and the maps location of countries defense bases , It is the most important military satellite because it does not let another country to put together an attack without another country knowing .
The satellites provide the meteorologists with the ability to see the weather on a global scale , They allow them to follow the effects of phenomena like the volcanic eruptions and the burning gas and the oil fields to the development of large systems like the hurricanes .
The satellites are used in the field of theoceanography , Now the marine scientists and the marine biologist can detect everything that goes on in the ocean , They use the satellites to detect the oceans affect on environment , they can analyze the wave patterns .
They can monitor the marine surface life , they can analyze the ocean tendencies and the currents , and they can get a complete synoptic view of the ocean , These things help them tell you what the water will be like , and help them find out about the ocean life .
It is very important to know that the satellites are the best sources of data for the climate change research , They monitor the ocean temperatures and the prevailing currents , The data acquired by the satellite borne radars were able to show the sea levels have been rising by three mm a year over the last decade .
Imaging satellites can measure the changing sizes of theglaciers which is difficult to do from the ground due to the remoteness and darkness of the polar regions , The satellites can determine the long term patterns of the rainfall , the vegetation cover , and the emissions of the greenhouse gases .
Earth observation satellites can monitor the ocean and the wind currents , the extent of the forest fires , the oil spills , and the airborne pollution , This information helps organize the emergency responders and the environmental cleanup .
The satellites can take the search out of search and rescue for the people in the distress in the remote regions , Distress radio beacons directly linked to a search and rescue satellite can lead the rescuers quickly and accurately to the land , the sea , or the air emergency location .
The remote sensing is observing and measuring our environment from a distance , They are put into the space to monitor the resources that are important for humans , They may track the animal migration , They locate the mineral deposits , they watch the agricultural crops for the weather damage .
These satellites can take the photographs and observe the areas all over the globe , they can monitor the areas in which the climate is very harsh , or which are nearly impossible to reach by land .
The satellites can detect the underground water and the mineral sources , They can monitor the transfer of the nutrients and thecontaminants from the land into the waterways , and they can measure the land and the water temperatures , the growth of the algae in the seas , and the erosion of the topsoil from the land .
Imaging satellites produce high resolution data of the entire landmass on earth which are used in the closely guarded military capability , but now anyone with an internet connection can find his house using Google Earth .
The most basic form of satellite imagery provides pictures of the current cloud conditions. This is a familiar sight on TV weather forecasts. However, satellite imagery can also undergo various types of quantitative processing to obtain information on important meteorological variables such as wind speed and direction, cloud height, surface temperature, sea ice cover, vegetation cover, precipitation, etc.
The first meteorological satellite was launched in 1960 by the USA and provided cloud cover photography. Originally, satellite images were treated purely as qualitative pictures, which were manually viewed and interpreted by meteorologists. Nowadays though, satellite imagery undergoes a great deal of mathematical manipulation and can yield quantitative analyses of atmospheric temperature, humidity, motion and many more meteorological variables. The major advantage of satellites is their ability to produce near-global coverage, which becomes especially important over oceans and remote, unpopulated land regions, where other methods of observation are impracticable. Over large areas of the southern hemisphere, satellites are the only means of Earth observation. As well as observing changes in surface features such as vegetation and sea surface temperature, satellite imagery can also capture the development of transient features such as clouds of water or ice and plumes of ash or dust.