Automatic Dependent
Surveillance Broadcast
The ADS-B Collision Avoidance
System is a significant part of the Regulatory Authorities's NextGen plan to
transform the airspace system globally. In view of the increasing number of
aircraft using the same airspace and ground facilities at the same time, it
requires the implementation of new technologies to maintain a high level of
performance and safety to ensure the safe operation of each aircraft with
adequate separation and zero tolerance. The development of this new collision
avoidance system known as Automatic Dependent Surveillance Broadcast (ADS-B)
has resulted from the successful deployment of global navigation satellite
systems (GNSS), such as GPS (Global Positioning System). ADS-B is an integral
part of the NextGen program. The implementation of its ground and airborne
infrastructure is currently underway all over the world. Some airspace has
already implemented the programme. Aircraft manufacturers already started producing modern aircraft with the incorporation of this new technology, ADS-B.
ADS-B Modes
The ADS-B has two segments that
is ADS-B OUT & ADS-B IN.
The transmission of ADS-B
information from an aircraft is known as ADS-B OUT and the receipt of ADS-B
information by an aircraft is known as ADS-B IN.
ADS-B OUT
ADS-B OUT combines the
positional data provided by a GPS sensor with on-board flight status
information of an aircraft, including as location, altitude, velocity, and
time. This information is then sent to other ADS-B enabled aircraft and ground
stations.
Two different frequencies are
used to carry these ADS-B broadcasts with data link capability. The first
frequency is an expanded use of 1090 MHz Mode-S transponder protocol system
known as 1090 ES. The second frequency is 978 MHz, largely being introduced as
a new broadband solution for use of general aviation implementation of ADS-B. A
978 Universal Access Transceiver (UAT) is used to accomplish this in USA. An
Omni-directional antenna, GPS antenna and receiver is required for ADS-B
operation. Airborne receivers of an ADS-B broadcast utilise the data to depict
the transmitting aircraft's location and movement on a flight deck display
similar to TCAS.
ADS-B IN
ADS-B IN offers features not
available in TCAS equipped aircraft. The ADS-B equipped aircraft are able to
receive several useful data to enhance situational awareness. On a distinct
frequency, traffic information services-broadcast (TIS-B) provide traffic
information from non-ADS-B and ADS-B aircraft. Any traffic data in the linked
network of ground stations, as well as ground radar monitoring of surface
targets, is supplied immediately to the flight deck of an aircraft via ADS-B
IN. This gives a more complete view than just avoiding collisions between
planes. The Flight Information Services-Broadcast (FIS-B) are also received by
ADS-B IN system. Weather text and graphics, ATIS information, and NOTAMS are
able to be received in aircraft that have 987 UAT capabilities.
Advantage of ADS-B
The ADS-B ground stations are
less expensive than conventional radar and are constructed in remote and
obstructed areas to proliferate ADS-B. ADS-B Ground stations in the Air Traffic
Management System communicate information from airborne ADS-B broadcasts with
other ground stations (ATMS). There is no requirement for human confirmation
when data is sent. The network is connected by microwave and satellite
transmissions.
For efficiently traffic
separation and control with less error, ADS-B has many advantages over
conventional ground-based radar used at present. The first advantage is the
entire airspace can be covered with a much lower expense. The existing old ATC
radar system that is in place is expensive to maintain and replace.
Additionally, these old Radar are consuming more power in compared to ADS-B
ground station Antenna. Furthermore, because the vector state is generated by
the aircraft with the support of GPS satellites, ADS-B offers more accurate
information. Weather is a greatly reduced factor with ADS-B. Ultra-high
frequency GPS transmissions are not affected. Increased positioning precision
enables for higher density traffic flow and landing approaches, which is a
clear requirement when operating more planes in and out of the same number of
terminals. The increased level of control also allows for better weather
routing and optimal fuel burn rates. Collision avoidance is extended to cover
runway incursion by other aircraft and support vehicles operating on the
airport's surface.
Testing & Maintenance of ADS-B
ADS-B test units are available
for skilled maintenance staff to use to ensure that ADS-B equipment is working
properly. This is crucial because reliable data from each aircraft and
throughout the ADS-B system is required for close tolerance air traffic
separation.
0 Comments