ADS-B is radically new technology that is redefining the paradigm of
COMMUNICATIONS - NAVIGATION - SURVEILLANCE in Air Traffic Management
today. Already proven and certified as a viable low cost replacement
for conventional radar, ADS-B allows pilots and air traffic controllers
to "see" and control aircraft with more precision, and over a far
larger percentage of the earth's surface, than has ever been possible
before.
"ADS-B" is an acronym that stands for:
| Automatic |
- |
It's always ON and requires no operator intervention |
| Dependent |
- |
It depends on an accurate GNSS signal for position data |
| Surveillance |
- |
It provides "Radar-like" surveillance services, much like RADAR |
| Broadcast |
- |
It continuously broadcasts
aircraft position and other data to any aircraft, or ground station equipped to receive ADS-B |
How Does It Work?
Far different from radar, which works by bouncing radio waves
from fixed terrestrial antennas off of airborne targets and then
interpreting the reflected signals, ADS-B uses conventional Global
Navigation Satellite System (GNSS) technology and a relatively simple
broadcast communications link as its fundamental components. Also,
unlike radar, ADS-B accuracy does not seriously degrade with range,
atmospheric conditions, or target altitude and update intervals do not
depend on the rotational speed or reliability of mechanical antennas.
In a typical applications, the ADS-B capable aircraft uses an ordinary
GNSS (GPS, Galileo, etc) receiver to derive its precise position from
the GNSS constellation, then combines that position with any number of
aircraft discretes, such as speed, heading, altitude and flight number.
This information is then simultaneously broadcast to other ADS-B
capable aircraft and to ADS-B ground, or satellite communications
transceivers which then relay the aircraft's position and additional
information to Air Traffic Control centers in real time.
The 978 MHz Universal Access
Transceiver ("UAT") variant is also bi-directional and capable
of sending real-time Flight Information Services ("FIS-B"),
such as weather and other data to aircraft. In some areas,
conventional non-ADS-B radar traffic information ("TIS-B"),
can also be uplinked as well.
ADS-B is also a relatively inexpensive
technology, with costs for equivalent radar coverage running
in the 0.1 to 0.05 range. Also, unlike radar, both the
footprint and power requirements for ADS-B are quite
small, allowing an ADS-B ground station to be installed in
even the most remote areas.
