En route to GPS-based air traffic control (images)

The Federal Aviation Administration is moving away from its antiquated radar-reliant air traffic control system toward one that's based on data from the global satellite network and promises to be more accurate, safe, and efficient. (i.e., fewer weather delays, crashes, and overall airport hassles.) Key to this next-gen system is a technology called Automatic Dependent Surveillance-Broadcast, or ADS-B.

With ADS-B, both pilots and controllers will see radar-like displays with highly accurate traffic data from satellites, according to the FAA. The displays will update in real time and don't degrade with distance or terrain. Better access to weather services, terrain maps, and flight information services should mean pilots can maintain safe distances from one another with less assistance from air controllers.

One component of ADS-B program is Traffic Information Service-Broadcast, or TIS-B, which shows air traffic radar targets. Here, for example, a TIS-B screen displays targets in the Anchorage (Alaska) Bowl area. Round-nosed targets are non-ADS-B (radar) aircraft. Arrow-nosed targets are ADS-B equipped aircraft.

The ADS-B technology has been tested by general aviation pilots in Alaska and air transport carriers in the Ohio River Valley. It's slowly being rolled out to other areas, with a goal of offering the services to throughout the entire National Airspace System by 2013, according to the FAA.

Another component of the program is Flight Information Service-Broadcast, or FIS-B, which is the ground-to-air broadcast of meteorological and aeronautical information to the cockpit. These displays can be textual and graphical, as in this moving map display of terrain at Windy Pass, Alaska.

This TIS-B graphic of air traffic targets in the Anchorage Bowl area is displayed on a Garmin MX20, the pilot's version of a gadget consumers have gotten to know.

And this FIS-B display shows a thunder storm in Matsu Valley, Alaska.

Another component of ADS-B is an Enhanced Visual Approaches Application. This includes a cockpit display for merging and spacing, shown here.

With the implementation of ADS-B, FAA researchers expect to see a significant drop both in aircrafts' environmental footprint and fatal accidents. This slide was taken from the agency's NextGen 101 plan  (PDF) for transforming a system it says is currently "not performing adequately" and is not "scalable."

A recent New York Times story on ADS-B and the FAA's NextGen plan said the U.S. air traffic system normally handles about 50,000 flights per day, and in the first half of 2008, more than 25 percent were either late or canceled. Flights are currently down, due the economy, but by 2025,  the FAA predicts daily air traffic will be up to 80,000 flights, the story said. "The current system is struggling badly. By 2025, it will not have a prayer."

The estimated cost of the NextGen plan, which maintains radar as a backup navigational technology, is about $4.6 billion in the first five years and $15 to 22 billion through 2025, according to the FAA.

This shot, provided by Anchorage, Alaska-based ADS-B Technologies, shows the ADS-B being used to follow flights.

ADS-B Technologies, which also provided this photo of China coverage, says the 978MHz Universal Access Transceiver is the most capable ADS-B datalink standard.

It just wouldn't be right to look at next-gen air traffic technology without looking back at the early days.

In 1936, just a year after an airline consortium opened the first Airway Traffic Control Station, enroute controllers at a Newark, N.J., facility (shown here) keep track of the position of planes with the help of good ol' maps and blackboards.

They had no direct radio link with aircraft. Rather, they used telephones to stay in touch with airline dispatchers, airway radio operators, and airport traffic controllers, according to the FAA.

Radar, a system that the British initially developed for air defense in the era preceding World War II, revolutionized air traffic control.

In 1946, the U.S. Civil Aeronautics Administration used a radar system developed for the Navy to open a radar-equipped airport tower for demonstration purposes, according the FAA.

 At the Washington Air Route Traffic Control Center in 1955 (shown here), standing controllers are using surplus Navy video generator equipment that presented radar data on a horizontal surface. Across this surface, controllers moved plastic "shrimp boats" indicating aircraft, much as similar markers had earlier been used on maps.

Click here for the FAA's complete photo history of air traffic control in the U.S.