Satellite - Essay Example

Satellites Name Class Unit Satellites Satellite is an artificial space segment that is placed on the orbit intentionally. The first satellite to be launched was Sputnik 1 in 1957 by former USSR. Since then, many countries have launched their satellites (Burleson, 2005). Satellite is composed of three main units which are the fuel system, the transponder and satellite telemetry controls. The transponder unit is used in receiving signals using the antennae from the ground station. The received signal is then processed using a broadband receiver and passes through a multiplexer. The frequency converter is used to reroute the signal using amplifier. Satellites are constructed with the main aim of reflecting the electronic signals. The fact that satellites are placed above the earth makes it possible for them to cover a large area. Satellites have a range of applications which are communication based. These are military, weather forecasting, radio TV broadcast, navigation and connecting remote areas (Grant & Meadows, 2004). Ground station is the earth segment of the satellite. The ground station has two main tasks. The tasks are uplink and downlink (Hughes.com, 2014). In uplink, the ground station transmits the data as signals. The signals are passed through a processor, amplifier and then a parabolic dish. The parabolic dish transmits the data to the satellite which is orbiting. In downlink, the ground station receives the signal. This works in the opposite manner to up linking. The signal is received via the parabolic antennae and processed (Gruntman, 2004). There are four different satellite types which are differentiated by the orbits in use. The satellites are identified through use of shape and diameter of each orbit (Gruntman, 2004). The four types are geostationary earth orbit which is 36,000 km above the earth surface. Looking from a point on the surface of the earth, this type of satellite appears to be stationary. These types of satellites are able to cover the surface of earth using just three stations. The satellite uses a circular type of orbit. The second type of satellite is the low earth orbit. This is located at 500-1500kms above the surface of earth. Using these satellites, the voice delay is reduced and has a better frequency use. The satellite has a better coverage globally. They are used in large numbers to provide global coverage and have a shorter lifespan. Medium earth orbit is located at 6000-20000kms above the surface of earth (Grant & Meadows, 2004). The movements of this type of satellite are slow which leads to simple design in making them. These types of satellite can cover a large area but suffers from delays due to large distance from earth. The orbit is also known as intermediate circular orbit while the last one is known as the highly elliptical orbit. The type of the orbits can be circular or elliptical. Satellites have been mostly used in communication (Hughes.com, 2014). These are satellites that are made specifically for communication. Satellites are made to provide communication services to a particular part of earth. Satellites are able to work in an efficient manner if their transmissions are made specifically for a certain area. This is due to fact that they minimize chances of interfering with other satellites. The antenna of the satellite plays a very important role. This is due to fact that it enables coverage of a specified geographical area (Grant & Meadows, 2004). The radio and TV dedicated satellites are used in providing access to TV and radio channels globally. Using these satellites, live events can be viewed through the world. This is mostly utilized in live matches, radio and global news. Using a small dish usually 30 to 40 cm, the channels can be viewed by everyone globally (Grant & Meadows, 2004). Military satellites are used in obtaining intelligence globally or as a weapon. There are satellites that are designed to destroy any warhead that the enemy might launch. Others are specially designed to destroy other satellites. The use that is dedicated to a satellite determines whether it’s military or civil (Grant & Meadows, 2004). These are satellites that are specifically designed to help in navigation. Using these satellites, it’s possible to have a precise localization in range of meters. These have led to installations of GPS in ships, aircraft and vehicles. At the moment, most of vehicle manufacturers have fitted GPS in their vehicles. This enables the drive to be guided in areas where they are stranded. The GPS system has also been used in managing the fleets and also guarding against theft (Hughes.com, 2014). Satellites have been used for a long time in assisting global communication. This replaced the cabled communication as it was cheaper to launch a new satellite. This method has started being replaced by the optic cable. Optic cable is cheaper and fast. Optical cables are also capable of reducing the delay that the signal encountered while using satellites (Hughes.com, 2014). The infrastructural development has not been uniform globally. There are areas such as Antarctica where there are no wired telephone. This leads to the use of satellites to help in communication. Satellites have immense use in world mobile communication. In areas which are not covered by the cellular phone systems, satellites have become an important asset. If there is no cellular service connectivity, a phone can switch and use satellite for communication (Hughes.com, 2014). These are satellites that are designed with an aim of monitoring the weather. The satellites monitor the climatic conditions on the earth. Through continuously monitoring, the satellites are able to predict the changes in weather conditions of an area. The satellite continuously takes the images of the earth to enable it predict the weather with accuracy. The image signals are then sent to earth using the earth station. Through use of weather satellites, it is possible to predict catastrophic changes such as hurricane. The weather satellites are also capable of monitoring changes in vegetation (Grant & Meadows, 2004). Using satellites, it is possible to cover a very wide area than any other alternative. A single satellite can cover a very large area making it appropriate and economical. Satellites are also capable of giving consistent information in different areas. The information is not affected by the area transmitted. In areas where it is hard to install infrastructure such as Antarctica, satellites provides the only alternative. Satellites can be used in any area irrespective of the existing infrastructure. Satellites are also easy to predict their costs. This is due to fact that their communication area does not depend on the distance. Unlike other alternatives, satellites can be easily deployed and at a lower cost (Hughes.com, 2014). If the user demands changes, the system is easily reconfigured. In some instances, network is required for a limited time. This would lead to high costs of infrastructure if other alternatives such as optic fiber are installed. The only solution which is practical is the use of satellite (Burleson, 2005). In conclusion, the invention of satellite has helped the world immensely. This is in the sectors of defense, weather, military, navigation, telephone and connecting remote areas. The main area that has benefited much from the satellites is communication. All applications of the satellites involve communications. Depending on the type of orbit, satellites have different classifications and life spans. Most of areas where there is no appropriate communication infrastructure can be assessed using satellites. Satellites also offer a cheap alternative to the existing technologies in such areas. A good example is Antarctica where communication is made possible through satellite. This is due to fact that satellites are also not affected by the geographical conditions. Despite this, satellites are being replaced in global telephone by the optical cables. This is due to their low cost and high speed of communication offered by fiber. References Burleson, D 2005, Space Programs Outside the United States, McFarland & Company, p. 43. Grant, A & Meadows, J 2004, Communication Technology Update, Focal Press. Gruntman, M 2004, Blazing the Trail. American Institute of Aeronautics and Astronautics, p. 426. Hughes.com, 2014, Satellite Communications In the 21st Century, Hughes.com, retrieved 15th march 2014 from, http://www.hughes.com/speeches/century21.html Read More