Surveillance department is responsible for provision and maintenance of Radar and related services for Air traffic management.
The TRACON project was borne out of the need to have a functional Radar system replace the previous terminal Area Radar which became very expensive to maintain due to obsolesce. This project was conceived to improve the level of air safety with expeditious and efficient control of aircraft within the Nigerian airspace, and in fulfillment of the Surveillance component of CNS/ATM as stipulated by ICAO hence the total coverage of the Nigerian airspace by Radar. TRACON is an acronym for the Total Radar Coverage of Nigeria.
The contract for the project was signed on the 7th of April, 2003 between NAMA and Thales ATM of France at the sum of 66,500,870 Euro.
TRACON PROJECT OVERVIEW
The project principally comprises four Primary Surveillance Radars (STAR 2000) and nine Monopulse Secondary Surveillance Radars (RSM 970M) to cover the following stations – Lagos, Kano, Abuja, Port Harcourt, Ilorin, Maiduguri, Talata-Mafara, Numan and Obubra configured to be interconnected through a VSAT network.
The project commenced with the first phase - Lagos installation, which was successfully completed in 2006, through several amendments, and in order to accommodate available funds, the project was split into several phases. Subsequent Phases comprise Kano, Abuja, Port Harcourt, Maiduguri, Ilorin, Numan, Talata-Mafara and Obubra was launched on August 28th 2008.
The four main stations that will be manned by ATC personnel have the Eurocat C Air Traffic Management System, VCCS (Voice Communication Control System) and VRS (Voice Recording System).
The various subsystems for each station are listed below:
Maiduguri, Ilorin, Numan, Talata-Mafara and Obubra
Lagos and Kano have the same status except for the addition of a Simulator Center to train Air Traffic Controllers in Lagos.
Abuja and Port Harcourt have the same status while Maiduguri, Ilorin, Numan, Talata-Mafara and Obubra are autonomous station that will be not be manned by ATC personnel. These five autonomous stations will only provide Radar data inputs to the four main stations.
The backbone of the configuration is a VSAT network. The network is a two-star topology with Lagos and Kano serving as hubs to the other stations, Lagos serves as hub to Port Harcourt, Ilorin, Obubra and Abuja while Kano serves as hub to Maiduguri, Talata-Mafara, Numan and Abuja.
Fiber Optics link exist between the ACC/APP center and Tower for Lagos and Kano, APP center and Tower for Port Harcourt.
PRIMARY AND SECONDARY SURVEILLANCE RADAR SYSTEM (PSR/MSSR)
The Primary Surveillance Radar detects and provides both range and bearing information of an aircraft within its effective coverage (60NM) by radio wave reflection for approach control.
The MSSR, with a range of 256NM, will provide aircraft range, azimuth, (ground) speed, altitude and identity. The system is multi-functional and extremely robust with capabilities for information on emergencies, radio communication failures and hijacks.
It works on the normal principle of SSR, which is, transmission of an interrogation signal at a known frequency (1030MHz); this signal activates the transponder in the target aircraft which retransmit the replies (coded information) at another frequency (1090MHz).
The radar data from the SSR comes in ASTERIX format into the p-lines. The p-lines convert the data to Ethernet packets before they are sent to the various processors for processing. This is quite interesting if you appreciate the interplay between the lines of divide.
ASTERIX is a structured Radar information exchange protocol developed by Eurocontrol while Ethernet is a LAN protocol developed by three companies Digital, Intel and Xerox in the 1980s but has its current version implemented by IEEE.
Technically, if we take the Lagos Eurocat ATM System as an example, it is designed to take processed radar inputs through the p-lines from five radars, namely Lagos, Port Harcourt, Abuja, Ilorin and Obubra.
The correct position for an aircraft within the Lagos airspace will be provided based on inputs from the three best radars in view i.e. Lagos, Abuja and Ilorin or Lagos, Port Harcourt and Obubra depending on the relative position of the aircraft to the Lagos radar.
The p-line, which is a communication interface with an IP address, interfaces the Radars, AFTN, OLDI and GRIB (Meteorological system). The ADS-B is designed to be directly interfaced to the network once an ADS-B station is setup.
RADAR PROCESSING SYSTEM
The Eurocat C system is the heart of the TRACON project. It is an automated system designed to consolidate the Radar data (that is processes Radar data and Flight data) for the controller which includes eliminating duplicate radar returns, ensuring the best radar for each geographical area is providing the data, and displaying the data in an effective format.
Eurocat-C system comprises p-lines, Radar Front Processors, Radar Data Processors, Flight Data Processors, servers, workstations and LAN switches including other ancillaries networked to provide the various Air Traffic Control positions. The system is very robust with a redundant Local Area Network.
The system operates on a version of Linux known as RedHat. This Operating System as modified by Thales is called THALiX. One unique feature of the Eurocat system is the automatic processing of Flight Plan sent through the AFTN. This is done by the FDP (Flight Data Processor). The FDP resolves squawk codes to call signs as well.
The Radar display presents to the Air Traffic Controller an easily understandable, graphic picture of the relative position of radar targets. It displays the processed radar data from various primary and secondary radars that represents the aircraft position and its related information, e.g. aircraft call sign, altitude, ground speed, aircraft category, etc.
This information is used by air traffic controllers to control the approach (App), and en-route (Acc) traffic. At each Controller Working Position, APP or ACC, there are two types of Screen Displays, the 2K x 2K for the Controller and the 1K X 1K for the assistant.
The system provides perfect ergonomics for the Controller and facilitates easy aircraft tracking by a simple click of the mouse at the various positions.
VOICE CONTROLLED COMMUNICATION SYSTEM
The TXM 550 VCCS handles the voice communication for Lagos center while Frequentis VCCS handles voice communication for Abuja, Kano and Port Harcourt. The system provides communication networks for the existing voice communication equipment, and facilitates connectivity for ground-ground and air-ground voice communication equipment.
The VRS, Voice Recording System, records Controller-Pilot communication. The system has capability for voice and radar data synchronization during playback.
Currently, all TRACON sites namely: Lagos, Kano, Abuja, Port Harcourt, Maiduguri, Ilorin, Talata-Mafara, Obubra and Numan have been successfully deployed and are fully operational.
ACC Area Control Center
AFTN Aeronautical Fixed Telecommunications Network
APP Approach Control Center
ATM Air Traffic Management
CNS Communication, Navigation & Surveillance
GRIB Grib Binary (Meteorological System)
GUI Graphic User Interface
HMI Human Machine Interface
ICAO International Civil Aviation Organization
IEEE Institution of Electrical & Electronics Engineers
IP Internet Protocol
MFT Multi Function Terminal
MSSR Monopulse Secondary Surveillance Radar
NM Nautical Mile
OLDI On-line Data Interchange
OPSUP Operational Supervisor
OSD On-Screen Display
OTA Operator Terminal Adapter
p-lines Power Lines
PSR Primary Surveillance Radar
RCMS Remote Control Monitoring System
SSR Secondary Surveillance Radar
TSUP Technical Supervisor
TWR Control Tower
VCCS Voice Communication and Control System
VoIP Voice-over Internet Protocol
VRS Voice Recording System
NAMA TRAINS PERSONNEL ON STRATEGIC SAFETY MANAGEMENT