Types of Satellites
There are many types of satellites based on the working of these space units. The most popular satellites may include geostationary orbits, low earth orbiting satellites and molniya satellites. The geo stationary satellite works on a very simple principle though still it is very efficient. It rotates around the earth in at a constant speed everyday. It is the most suitable design for communication applications. The antennas which are working at the ground have to be aligned with the direction of the satellite and hence they work accordingly. There is no need for extra expensive equipment to be deployed with these types of satellites. Low earth orbiting satellites or most commonly known as LEO is a circular trajectory which is placed at a distance of about 400Km above earth. These satellites can be used to establish satellite phone connections. Molniya satellites are considered to operate below the equator. These satellites are often used to provide telephonic communication and TV broadcasting.
The Communication of the Satellite
The telemetry, tracking and command system usually monitors the working of the satellite system. These systems help to direct and locate signals from the satellite and ground station. Or in other words these systems help in uplink and downlink of communication. The signals produced are in equal proportion to the quantity that is being measured. The information which is transmitted through these satellites includes everything. The transmission and carrying of signal between satellite and earth can be explained best considering a command and track module. The command system is the one which is present on the receivers end like on earth based stations usually. This system works by decoding, receiving and sometimes sending information. The track system on the other hand guides and monitors the working of the satellite and its related movements. The communication of the satellites is completed using transponders and communication antennas. The transponders are two mode devices which contain an input de multiplexer and a power amplifier. Both of these receivers operate on a single communication mode. These antennas receive and send uplink and down link signals. Satellites communicate with ground systems such as the curved dishes, which are capable of reflecting outgoing systems from their horns. Moreover they can also return the signals of the incoming beams.
The Working of the Satellites
Any satellite cannot work without power and the key components such as receivers and antennas. Satellites are connected to the computer systems for the processing of data. The data is received and sent back using satellites. These satellites can gather the instructions from these systems as well. Satellites constitute many sensors, these sensors enable it to process the data and send it to earth. Telemetry system is a key to the purpose and operation of satellite working. Satellites send encoded information to the earth based stations. This information is decoded using transponders. The working of satellites is possible with the power distribution to all the components connected to the satellite. The power supply is dependent on the use of the satellite. Short training satellites are usually powered by cells and batteries. The power for the long training satellites is usually derived from the solar cells mostly. In this way the fuel expense can also be lowered. Satellite communication can serve many purposes form TV broadcasting and telephone communication to weather updates.
As an practical application example, GRS Tracking is another the example of satellite.