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Functions of Various Air Traffic Control Equipment for the Airport

Radar Data Processing & Display System (RDPDS), Flight Data Processing System (FDPS) and Simulator System (SIM) -- (The heart of the air traffic control system)

Please click to see a larger image(Open with new window)The RDPDS processes the radar data from various primary and secondary radars to present the aircraft position and its related information, e.g. aircraft callsign, altitude, ground speed, aircraft category, etc. on the radar display. This information is used by air traffic controllers to control the approach/departure, terminal and en-route traffic.

The FDPS processes the flight plan data from aeronautical messages and prints out flight progress strips automatically for use by air traffic controllers to assist in updating/monitoring of the aircraft flight profile, such as flight route, estimated time of departure/arrival, flight level, expected times at reporting points, cruising speed, etc.

The SIM is a replica of the operational system and is used for the training of air traffic controllers and evaluation of air traffic control procedures.


Primary Surveillance Radar (PSR)

This type of radar detects and provides both range and bearing information of an aircraft within its effective coverage by radio wave reflection. Depending on the application, the coverage will be within 80NM for approach control or within 200NM for en-route control purpose.

A short range PSR is installed at Sha Chau to detect aircraft operating within the approach and departure areas of the HKIA.


Secondary Surveillance Radar (SSR)

This type of radar provides, after processing, the range, bearing, altitude and identity (callsign) of an aircraft. The coverage can reach 250NM. A SSR can provide more useful information than PSR but is subject to the proper functioning of the aircraft's transponder. To provide the best accuracy of aircraft targets, the SSR is usually paired with a PSR for air traffic control purpose.

A SSR is co-mounted with the PSR at Sha Chau and serves to supplement the coverage of existing SSRs at Mount Parker and Beacon Hill.


Surface Movement Radar (SMR)

This radar is mounted on top of the Aerodrome Control Tower for surveillance of the movement of aircraft and vehicles on the runway and taxiways. The accurate information provided enables the tower controller to maintain a smooth flow of traffic during low visibility or darkness.


Advanced Surface Movement Guidance and Control System (A-SMGCS)

The A-SMGCS employs both the multilateration and Automatic Dependent Surveillance-Broadcast (ADS-B) technologies for enhanced surveillance of aircraft and vehicle movements on the airfield, and provision of conflict and runway incursion alerting functions for added air traffic control safety and efficiency.


Control Tower Simulator (CTS)

This simulator uses the latest imaging technology to simulate the airport environment, during day or night, and under good or bad weather conditions. It is an effective tool for the training of air traffic controllers on aerodrome control.


Off-the Shelf Simulator (OTS)

This is a separate radar simulator used for area control and radar control training of controllers.


Instrument Landing System (ILS)

A standard ICAO precision landing aid to provide accurate azimuth and descent guidance signals for use by aircraft for landing on the runway under normal or adverse weather conditions. The equipment serving both approach directions of the south runway has been certified for Category II operation with a decision height of 15m. For the north runway, similar Category II equipment is installed for aircraft approaching from the southwest while more precision Category III equipment, which supports blind landing from northeast direction, has also been provided.


Doppler Very High Frequency Omni-directional Radio Range and Distance Measuring Equipment (DVOR/DME) System

Standard ICAO radio navigational aids used to provide bearing and distance information to aircraft and to define air traffic control routes for en-route, terminal and instrument approach/departure procedures.
DVOR/DME stations are installed at Tung Lung (TD), Lung Kwu Chau (LKC) and Siu Mo To (SMT) to support departure and missed approach flight paths of the HKIA.


Aeronautical Information DataBase (AIDB) System

A database and information display system used for the generation, distribution and storage of Notices to Airmen (NOTAM), meteorological information and forecasts, and other aeronautical information for use by air traffic service operators and pilots. The information can be accessed via computer terminals.


Automatic Message Switching System (AMSS)

A standard ICAO ground-to-ground communication system for the exchange of air traffic control messages within the Aeronautical Fixed Telecommunication Network (AFTN) between Hong Kong and overseas airports.


Very High Frequency/Ultra High Frequency (VHF/UHF) Communication Equipment

This includes the radio and signal transmitters and receivers operating on various frequencies used for both long-range and short-range air/ground communications with aircraft.
The equipment are installed at Cape D'Aguilar, Mount Butler, Victoria Peak, Tai Mo Shan, North Lantau, Mount Parker, Beacon Hill, and on-Airport sites.


Speech Processing Equipment (SPE)

This is a computerised voice communication system between pilots and air traffic controllers, and between air traffic control positions in the Air Traffic Control Centre, Aerodrome Control Tower, Rescue Coordination Centre and Aeromobile Centre by using pre-set switching and distribution of various aeronautical frequencies and direct communication lines.


Voice Recording System (VRS)

The system is used for 24-hour recording of over 500 air/ground radio communications and telephone communication channels between Air Traffic Control Centre of CLK and other external agents. The recordings are essential for the investigation of aircraft incidents and accidents.


Automatic Terminal Information System (ATIS)

A VHF broadcasting system for continuous dissemination of vital information (such as updated airfield, meteorological and navigational aids serviceability information, etc.) to pilots departing from or arriving at HKIA. Public can also gain access to the information at telephone no. 3141 2820 and 3141 2705.


Automatic Volmet Broadcast System (AVBS)

The system is used to broadcast automatically recorded meteorological information for various airports including Hong Kong and the neighbouring aerodromes e.g. Guangzhou, Naha, Taipei, etc. at regular intervals.


Microwave Link System (MLS)

The system is used for conveyance of radar and air/ground communication signals, equipment status indication and remote control signals between various remote CAD radar, navigational aid and communication stations and the operation and maintenance centers at the HKIA.


Master Clock System (MCS)

A centralized clock system in the ATCX to set the time standard according to international time reference derived from the Global Positioning System (GPS). It is also used to synchronise the time signals between all elements of the CLK ATC system, as well as to display standard times for controllers' reference.


Non-directional Beacon (NDB)

A standard radio navigational beacon installed at the southwest end of the runway promontory to provide additional track guidance to aircraft departing from the runway.


The Backup Air Traffic Control Centre/Tower (BATCC/ Backup TWR)

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The Backup Air Traffic Control Centre/ Tower

In the event of serious fire or hazardous incidents which render the Air Traffic Control Complex (ATCX) not able to perform its original function, normal air traffic control (ATC) services will be severely disrupted. To maintain the continuous ATC services, a Backup Air Traffic Control Complex (BATCX) equipped with all essential backup ATC facilities will be activated. These backup facilities can support about 30 per cent air traffic control handling capacity to maintain a safe and orderly flow of air traffic.

The BATCC and Backup TWR are situated to the North of the ATCX. The equipment used are the same as those in the main operational centers so as to minimise training and remain operationally compatible with the existing ATC systems.


Air Trffic Service Message Handling System (AMHS)

A new generation of ground-to-ground message introduced by ICAO for exchange of Air Traffic Service messages with enhanced functions and quality of service