GPS Satellites and Signals: How does it work?

GPS Satellites and Signals: How does it work?

Flight schools help their students to be familiar with all the aircraft equipment. Student pilots will be hearing about GPS most of the time during training. As a pilot trainee, you must know what GPS means and its use.

GPS stands for Global Positioning System, a satellite-based system that helps in navigation and made up of a network of 24 satellites placed into orbit and transmitting signals to earth. GPS receivers retrieve this information and calculate the exact location of the user by using triangulation. After receiving the signals, GPS receivers determine how far it is from the satellite location. Utilizing the measurements of distance given by a few more satellites, the receiver can easily determine the position of the user and display it on the electronic map of the GPS unit. In order for a GPS receiver to calculate a 2D position and track movements, a GPS receiver must be linked to at least three satellites.

GPS receivers do not only concentrate on determining the location but also other information like the speed, track, trip distance and much more. Even the weather can be calculated by GPS.

Accuracy of GPS

GPS receivers are very accurate because of its parallel multi-design. As designed by Garmin, it has 12-channel receivers that are quick to respond onto satellites. They also maintain strong locks that enable it to get all the necessary information that is needed. They are designed with all the advancements in today’s technology so that it can keep pace with all the other latest equipments that we have right now.

Latest versions of Garmin’s GPS receivers have Wide Area Augmentation System (WAAS) capability that can improve the accuracy to less than an average of three meters.

GPS Satellite System

GPS is composed of 24 satellites that are constantly orbiting the earth about 12,000 miles above the earth at roughly 7,000 miles per hour. They are powered by solar energy and have backup batteries in case a solar eclipse occurs. There are two rocket boosters on each satellite for balance and to keep them on track.

GPS Signals

There are three different bits of information that a GPS signal has- a pseudorandom code which is commonly known to be the ID code that identifies the satellite that is transmitting the information; ephemeris data which is constantly being transmitted by satellites and contains information that are important for the status of the satellite, the current time and date; and almanac data which tells the GPS receiver where each GPS satellite must be at a certain time of the day.

GPS is representative of the most advanced equipment that is being offered for aircraft like Cirrus.

Coast Flight Training uses Cirrus models that have GPS to enhance safety and situational awareness.