**Global Positioning System** (“GPS”) technology is used to accurately determine position in 3 dimensions on or above the earth’s surface

##### In this post:

- What it is
- How it works
- Mathsing
- Applications
- Limitations

##### See also:

- Satellite
- Strava

## 1. What it is

The GPS consists of many satellites orbiting the Earth in a very precise pattern. The system is operated by the U.S. Department of Defense (“DoD”) for use by both the military and the general public.

## 2. How it works

The GPS satellites broadcast microwave signals that are received by GPS receivers on or near the Earth’s surface. The receiver device then calculates the location. If the receiving device is moving it can make additional calculations such as displacement/distance, speed, average speed and more. A device may be within the range of more than 10 satellites at any time and must be connected to a minimum of three at all times to function.

GPS signals include *ranging signals*, used to measure the distance to the satellite and *navigation messages*. The navigation messages include *ephemeris* data, used to calculate the position of each satellite in orbit and information about the time and status of the entire *satellite constellation* called the *almanac*.

## 3. Mathsing

Essentially lots of triangulation must take place.

The Cartesian coordinate system consists of a horizontal x-axis and a vertical y-axis.

On a Cartesian plane (2 dimensions) we can use x and y coordinates to make measurements based on plot points using Trigonometry and stuff.

“Distance between two points is the length of the line segment that connects the two points in a plane. The formula to find the distance between the two points is usually given by ” ^{[1]}

## 4. Applications

- Military use.
- GPS-enabled navigation units for motor vehicles, boats and aircraft.
- GPS-tracking for safety and security measures.
- Personal GPS units for sports tracking.

## 5. Limitations

GPS signal requires direct line-of-sight and will not penetrate a dense tree canopy, or when the receiver is under (even very shallow) water or near the base of a cliff/in a deep ravine.

#### References:

- Admin (2021)
*Distance Between Two Points Formula – Definition & Examples*,*BYJUS*. BYJU’S. Available at: https://byjus.com/maths/distance-between-two-points-formula/. (Accessed: 23 April 2024). - CalculatorSoup, L. (2024)
*Distance Calculator 2D*,*CalculatorSoup*. Available at: https://www.calculatorsoup.com/calculators/geometry-plane/distance-two-points.php (Accessed: 23 April 2024).