Lab Log Entry #7

A) LEO, MEO, and GEO satellites


LEO or Low Earth Orbiting satellites are used for the coverage of small areas on the Earth and travel at high angular velocities, which allows it to keep its orbit constant. LEO's are deployed in satellite constellations. Because LEO satellites cover such a small area on Earth there needs to be many LEO satellites to keep orbit over the whole Earth. An example of a satellite constellation that a LEO can travel in is a GPS, it allows you to find your way around when you are driving or hiking somewhere and you don't know where you are going.

MEO or Medium Earth Orbiting satellites are satellites that oribit about 100 miles to 1000 miles above the Earth's surface; these types of satellites are higher up than a LEO satellite but are lower than a GEO satellite by means of where they are in the universe. It takes a MEO satellite about 2-12 hours to complete its orbit around the Earth. Their orbit pattern is an almost perfect circle which infers that its speed and altitude is always constant. Because of a MEO satellites altitude Earth based transmitters that have low frequencies can contact them. When there are several MEO satellites there can be global wireless communication all around the world, it would take many more than 7 LEO satellites to have the same amount of coverage that a MEO satellite does. An example of a MEO satellite is a satellite phone.

GEO or Geosynchronous Earth Orbiting satellites are satellites that constantly passes points on the Earth on a regular basis. If there is a GEO satellite over the equator than it is known as a geostationary satellite. GEO are usually sationed over parts of the equator and are used for the transmitting and recieving of antennas on Earth that don't need to track satellites to work. An example of an antenna that a GEO has been responsible for revolving are global communication, weather forecasting and television broadcasting. A disavantage of a GEO satellite is its altitude, because GEO satellites are so far away from the Earth it takes a radio signal about .25 seconds to reach the satellite and return to Earth, this is a problem because radio signals could interfere with telecommunication on Earth, making it harder for people to communicate between each other.