The Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. The system provides critical capabilities to military, civil and commercial users around the world. It is maintained by the United States government and is freely accessible to anyone with a GPS receiver. A GPS receiver calculates its position by precisely timing the signals sent by GPS satellites high above the Earth. Each satellite continually transmits messages that include the time the message was transmitted satellite position at time of message transmission In 1956, the German-American physicist Friedwardt Winterbergproposed a test of general relativity (for time slowing in a strong gravitational field) using accurate atomic clocks placed in orbit inside artificial satellites. (Later, calculations using general relativity determined that the clocks on GPS satellites would be seen by Earth's observers to run 38 microseconds faster per day, and this was corrected for in the design of GPS.) The gps in my opinion is quite a useful tool. It allows confused travelers to navigate their surroundings with the ease of a native person Cost Purchasing a GPS based on price can be a major disadvantage. If you purchase a "bargain GPS," you will get what you pay for, and features such as traffic and up-to-date maps could be lacking. Reception GPS devices are limited by having clear access to the satellites that provide the tracking. In locations with tall buildings or sparse coverage, reception can be poor. These are just a few of the problems there quite a few more. Dr. Ivan Getting was born in 1912 in New York City. He attended the Massachusetts Institute of Technology as an Edison Scholar, receiving his Bachelor of Science in 1933. Following his undergraduate study at MIT, Dr. Getting was a Graduate Rhodes scholar at Oxford University. He was awarded a Ph.D. in Astrophysics in 1935. In 1951, Ivan Getting became the vice president for engineering and research at the Raytheon Corporation. The first three-dimensional, time-difference-ofarrival position-finding system was suggested by Raytheon Corporation in response to an Air Force requirement for a guidance system to be used with a proposed ICBM that would achieve mobility by traveling on a railroad system. Technology is a valuable tool that in current most people cannot live without. These tools allows to do things such driving to another state, which in earlier times would have taken weeks whereas now it takes hours. Technology is a important tool that helps day in and day out with ease.