GPS Navigation Technologies

Navigation technology has come full circle, from the ancient mariners who looked to the stars to today’s jet jockey who looks to a constellation of GPS satellites orbiting in space.

The Global Positioning System (GPS) was developed by the U.S. Air Force. Today, it serves virtually every sector of our economy, from boating to hiking to trucking. Yet nowhere has GPS improved navigational accuracy and safety more than in aviation.

Color Moving Maps

Today’s pilots can use GPS navigation systems that show their exact position on an animated color moving map. These electronic maps show all the features of the surrounding airspace, including airports, restricted areas, control zones, and the details of instrument approaches. In addition, these maps can show all the major land features, including roads, lakes, rivers, mountains, and tall surface obstructions like TV broadcast antennas.

ILS — The Original Technology for Precision Approaches

In bad weather, aircraft must rely upon their navigational systems to guide them all the way to the runway’s surface. Today’s Instrument Landing System (ILS) requires land-based radio equipment to be placed at the end of a runway. These ILS radio systems are expensive to install and maintain. As a result, only about 700 U.S. airports have this specialized equipment.

GPS — Used Today for Non-precision Approaches

GPS is widely used to guide airplanes to safe landings by using what are called “non-precision” approaches. While these approaches are in fact precise, they are only used to guide the airplane down to within about 500 feet of the runway surface, and require visibility of at least one mile.

GPS with WAAS — Bringing Low-cost Precision Approaches to Thousands of Small Airports

Many GPS systems are now augmented by the Wide Area Augmentation System (WAAS). This technology helps GPS provide vertical guidance all the way to the runway surface.

By eliminating the need for costly and hard-to-install ILS systems on the ground, airborne GPS systems using WAAS allow aircraft to fly precision approaches to thousands of small community airports that currently don’t have ILS systems. This can reduce air traffic congestion at bigger airports, reduce air traffic delays during bad weather, and increase safety at all airports.