ADS-B surveillance technology allows aircraft to use GPS to share accurate position data with ATC and other aircraft. Global Navigation Satellite System (GNSS) is the standard generic term for satellite navigation systems with global coverage. GPS is specific to the United States' GNSS system. This allows continuous and automatic broadcasts of data rather than just responding to interrogations (like a transponder does). Pilots and controllers can monitor other aircraft more accurately and frequently than with radar. It's the first step, and a viable low cost conventional radar replacement, in the FAA's transition from radar-based to satellite-based air traffic control.
ADS-B is fundamental to the foundation of NextGen and will directly affect aircraft operation in a substantial portion of the nation's airspace effective January 1, 2020.
ADS-B provides foundational technology for improvements related to the NextGen and Single European Sky Air Traffic Management (ATM) Research Programme (or SESAR). As NextGen refers to the effort of the US FAA to transform the ATC system to support a larger volume of airplanes more efficiently, SESAR is a similar effort in Europe.
On November 22, 2016, the FAA suspended the authorization that NavWorx Inc. uses to manufacture certain Automatic Dependent Surveillance-Broadcast (ADS-B) navigation units through an emergency order. The suspension order resulted after NavWorx declined on repeated occasions to allow FAA personnel to perform the required inspections.
An internal Global Positioning System (GPS) chip that does not meet the FAA's minimum performance standards for transmitting an aircraft's accurate location may be contained in two versions of the company's ADS600-B units, carrying part numbers 200-0012 and 200-0013.