GPS TEST
requirements for lat/long
A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (latitude and longitude) and track movement.
GPS math
Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. S = D/t D = S • t
how satellites work pt.2
GPS receivers (hand-held devices) take this information and use triangulation (surrounding a location with at least 3 positions) to calculate the user's exact location.
satellite energy source
GPS satellites are powered by solar energy.
how satellites work
GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth (radio waves).
GPS original purpose
GPS was originally intended for military applications, but in the 1980s, the government made the system available for civilian use.
necessary conditions for GPS
GPS works in any weather conditions, anywhere in the world, 24 hours a day.
conclusion of how satellites work
Now, with distance measurements from a few more satellites, the receiver can determine the user's position and display it on the unit's electronic map.
after GPS finds lat/long things it can do
Once the user's position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time and more.
satellite facts
The 24 satellites that make up the GPS space segment are orbiting the earth about 12,000 miles above us.
What is GPS?
The Global Positioning System (GPS) is a satellite-based navigation system made up of a network of 24 satellites placed into orbit by the U.S. Department of Defense.
satellite speed
These satellites are traveling at speeds of roughly 7,000 miles an hour.
orbit facts
They are constantly moving, making two complete orbits in less than 24 hours.
satellite precautions
They have backup batteries onboard to keep them running in the event of a solar eclipse, when there's no solar power. Small rocket boosters on each satellite keep them flying in the correct path.
requirements for lat/long/alt
With four or more satellites in view, the receiver can determine the user's 3D position (latitude, longitude and altitude).