Global Positioning System

High school (ages 12+)
Geography

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/global-positioning-system

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the satellite orbit?Medium Earth Orbit (MEO) at approximately 20,200 kilometers altitude
2. What is the positioning principle?Utilizes trilateration based on time-of-flight measurements from at least four satellites
3. What is the Global Positioning System (GPS)?GPS is a system that uses satellites in space to tell you exactly where you are on Earth. It works like a magic map in the sky.
4. How does a GPS receiver find its location?A GPS receiver looks at signals from at least four satellites. By measuring how long the signals take to arrive, it calculates the distance to each satellite and uses those distances to find its own spot on the globe.

Ephemeris Data: Precise orbital information for each GPS satellite, broadcast in its signal.
Selective Availability (SA): An intentional degradation of the civilian GPS signal, deactivated in 2000.
Global Navigation Satellite System (GNSS): A general term for satellite systems that provide autonomous geospatial positioning.