GPS

- Overview

GPS stands for Global Positioning System. It's a satellite-based radio navigation system that provides positioning, timing, and navigation services. The US government owns GPS and the US Air Force operates it. 

GPS works by sending impulses to an earthbound receiver. It can pinpoint a three-dimensional position to meter-level accuracy and time to the 10-nanosecond level, worldwide and 24/7. GPS works in any weather conditions, anywhere in the world, 24 hours a day, with no subscription fees or setup charges. 

GPS is used by almost all military aircraft, surface ships, and submarines, as are some land vehicles and ground troops. 

GPS may also refer to a GPS tracking unit, which is a navigation device that uses satellite navigation to determine its movement and location. Some GPS receivers are so accurate they can establish their location within 1 centimeter. 

- Applications of GPS

GPS is a network of more than 30 satellites that orbit the Earth twice a day. Each satellite sends out unique signals at the speed of light, and GPS receivers use trilateration to calculate a user's location. GPS receivers don't need an internet connection or cell service to calculate a user's location. 

GPS can be used for many purposes, including: 

• Location: Determining a position
• Navigation: Getting from one location to another
• Tracking: Monitoring object or personal movement
• Mapping: Creating maps of the world
• Timing: Bringing precise timing to the world

GPS can also be used in geofencing, which is when a mobile app or software uses GPS, radio frequency identification (RFID), Wi-Fi, or cellular data to define a virtual geographical boundary. When a device enters or exits that boundary, a targeted marketing action is triggered.

- How GPS Works

Global Positioning System (GPS) is a United States government satellite navigation system that currently consists of at least 30 operational satellites. GPS works 24 hours a day, anywhere in the world, in any weather conditions, with no subscription or setup fees. 

The U.S. Department of Defense originally put these satellites into orbit for military use but transitioned to civilian use in the 1980s.

Here's how GPS works:

• GPS satellites send out signals
• GPS receivers listen for these signals
• GPS receivers calculate their distance from at least four satellites
• GPS receivers use the time it takes for signals to arrive to calculate their distance from each satellite
• GPS receivers use the information from the satellites to calculate their exact location

GPS satellites orbit the Earth twice a day in precise orbits. Each satellite transmits unique signals and orbital parameters that allow GPS devices to decode and calculate the satellite's precise position. The GPS receiver uses this information and trilateration to calculate the user's exact location. 

Essentially, a GPS receiver measures the distance to each satellite by how long it takes to receive the transmitted signal. Using distance measurements from more satellites, the receiver can determine the user's location and display it electronically to measure your running route, map your golf course, find your way home or adventure anywhere. 

Today, GPS is built into all types of devices, such as smart watches, satellite communicators, cars, ships, and more. To calculate your 2D position (latitude and longitude) and track movement, a GPS receiver must lock onto the signals of at least three satellites. 

The receiver can determine your 3D position (latitude, longitude, and altitude) when four or more satellites are in view. Generally speaking, a GPS receiver will track eight or more satellites, but this depends on the time of day and your location on Earth. There are devices that can do all of this from your wrist.

Once your location is determined, the GPS unit can calculate additional information such as: speed, bearing, track, travel distance, distance to destination, dunrise and sunset times, and more.

[More to come ...]