TIS-B and FIS-B

The FAA ground station receiving the airborne data rebroadcasts back to the sky once every second. This data broadcast is called TIS-B. The ground station also broadcasts additional flight information such a graphical weather display and NOTAMS. This data is called FIS-B.

There are three distinct benefits of ADS-B over radar:

1, GPS reported positions are more accurate than radar and more frequently reported. Unlike radar, ADS-B accuracy does not seriously degrade with range, atmospheric conditions, or target altitude. Update inter­vals do not depend on the rotation speed or reliability of mechanical antennas. This means that closer spacing can be used than presently, and this provides much needed capacity improvements in congested airspace.

2, ADS-B is less expensive to deploy than ground radars. ADS-B can also be deployed in areas where there was previously no cov­erage by radar, for instance, ocean routes and the Gulf of Mexico, where only proce­dural separation could be employed. These areas can now receive air traffic control separation and free up needed airspace.

3, Other aircraft with ADS-B In equipage can receive the ADS-B broadcast to facilitate aircraft avoidance.

The totality of NextGen benefits will depend on the successful development of FAA ground – based systems, space-based systems, alterna­tive fuels, engine and airframe improvements, advanced avionics capabilities, and airport infrastructure.

Implementation Process

The FAA published its Roadmap for Perfor­mance-Based-Navigation in order to detail three periods of implementation: Near Term (2005­2010); Mid Term (2011-2015); and Far Term (2016-2025).

By 2012, most of the Near Term objec­tives for implementation had been achieved. The ADS-B ground-based infrastructure had more than 400 ground stations operational. These sta­tions were providing satellite-based surveillance coverage for the east, west, and Gulf Coasts and most of the area near the U. S.-Canadian border (see Figure 36-1). АТС is already using this foundation NextGen technology to sepa­rate equipped aircraft at several areas, including Uouisville, Kentucky; Juneau, Alaska; Flouston; and Philadelphia. The total complement of 700 ground-based stations is expected to be opera­tional by 2014 and will allow controllers to use the airspace more efficiently.

A significant volume of PBN arrival and departure procedures for commercial airports, as well as high and low altitude en route charts, have been published. Access to general aviation airports has been improved through the publica­tion of PBN approach procedures using Area Navigation Wide Area Augmentation System (WAAS) Uocalizer Performance with Vertical Guidance (LPV) charts. LPVs are operationally equivalent to Instrument Uanding System (ILS) approaches but require no costly infrastructure or maintenance. As of February 2011, there were 2,772 LPVs at 1,400 airports nationwide.