Prompt Cast
The History and Evolution of GPS
TLDR GPS, the world's first global utility, has evolved from a military navigation system to a ubiquitous tool used for various applications worldwide. It has gone through several milestones, including opening up for civilian use, advancements in accuracy and functionality, and the development of satellite navigation systems by other countries.
Timestamped Summary
00:00
GPS devices are now ubiquitous and are used for a wide variety of applications all over the world, making it the world's first global utility.
02:01
In 1960, the first satellite navigation system called Transit was tested to provide location information to Polaris nuclear submarines, and in 1973, the framework for a new system called NAVSTAR was laid down, with the first satellite launched in 1978, intended for military use.
03:53
In 1983, after Korean Airlines Flight 007 was shot down, President Reagan ordered that GPS be open for free civilian use, but with selective availability, limiting accuracy for the public, until President Clinton ended selective availability in 2000, allowing civilians the same level of accuracy as the military.
05:50
GPS works in three dimensions and requires four satellites to accurately determine a position, with each satellite equipped with atomic clocks and the ability to detect nuclear explosions, while the key to the system is time and the distance to the satellites is calculated from the speed of light.
07:39
The GPS system relies on downloading the Almanac and Ephemeris, adjusting satellite clocks for relativity, and monitoring the health and accuracy of the satellites from ground stations around the world.
09:30
The United States military runs the GPS system, which has led other countries to develop their own satellite navigation systems, such as the Russian GLONASS system and the European Union satellite navigation system.
11:22
The future of the GPS system includes the launch of GPS-3 satellites, which will provide more accurate location information, be harder to jam, work better with other countries' systems, have a longer lifespan, and lower operating costs.
