In the past, humans had to go to pretty extreme measures to keep from getting lost. They erected monumental landmarks, laboriously drafted detailed maps and learned to read the stars in the night sky. All of these ways were difficult, but what if their guide was a collection of satellites that monitors the earth by receivers, this is known as a Global Positioning System (GPS).

The Global Positioning System (GPS) is a "satellite-based navigation system made up of a network of 24 satellites placed into orbit by the U.S. Department of Defense" (what is GPS). It was intended for military applications, but after years it was developed for civilians’ usage. The technology behind the Global Positioning System is quite complex but can be summarized into simple terms, the system consists of three segments: Space segment including 24 operating satellites, Control segment including monitor and control stations that maintains the satellites, and user segment consists of GPS receiver. The GPS can be clarified simply in this example: you turn on your GPS receiver and ask for your location, the receiver sends signals to the satellites and it calculates your requested information then send it to your receiver by appearing on the screen. (GPS Overview 2011)

I think by providing this technology, life became easier and safer. So let me talk about the uses and benefits of it. GPS technology has many applications on land, at sea, and in the air. For example many of new cars have a GPS service to help you in finding locations with the maps it provides; also cell phones and new cameras have this service. Different companies use it for distributing or delivering home appliances and also food products by different restaurants, also companies use it in their vehicle (tracking software) that helps in better planning and supervising vehicle movements and for timely delivery of the construction material and overall for better dispatching and advanced communication material. Also GPS technology is used in aircrafts, ships, agriculture, and environment. Of course firefighters, police and emergency medical personnel can respond faster and more accurately with GPS, and we don’t forget that the government and military is the primary beneficiary of this technology. You can use offline GPS by downloading the maps on your GPS device and tag the important locations for you. (Industries are using GPS 2008)

Although GPS provided amazing benefits, but it has disadvantages so here are some: Reception can be poor by not having clear access to the satellites, Turn-by-turn directions are not available on every type of GPS device, Maps on GPS receivers are not updated in real time for all models it means that your receiver maybe lead you onto a road that is closed or no longer exist and it could also miss new roads and businesses. So be careful when using GPS devices from these disadvantages. (Kirk. A)

In the end, I want to say that GPS has made it easier and safer to travel and do businesses. By owning a GPS device, your life became easy and you can dispense the maps and asking people where you are or where to go.

References

1. What is GPS? , Garmin Ltd. 2011. Available from:

>http://www8.garmin.com/aboutGPS/<

2. GPS Overview, GPS.GOV 2011. Available from:

> [15 March, 2011] http://www.gps.gov/systems/gps/<

3. Kirk. A, Disadvantages of a GPS System, eHow. Available from:

> http://www.ehow.com/facts_4811055_disadvantages-gps-system.html<