Aviation is a global phenomenon and every state/country has certain responsibility within its jurisdiction pertaining to Civil Aviation.
The National Airport Authority, a government of India undertaking, for planning, development and management of Air Traffic Control and Communication, Navigation and Surveillance Services over Indian air space, has to look beyond technical innovation to meet these challenges.
CATC has been created, since1948, to meet that objective.
INTRODUCTION CNS/ATM was endorsed by the member states of ICAO in 1991. It should be in full operation by 2010. CNS / ATM is going to change the way pilots and controllers communicate .Communication will be based on data link (digital data) .Voice communication will be used as backup and will gradually becomes less important. Data based communication has many advantages over voice communication especially on oceanic routes and over continental land mass where there are few navigational aids.
CNS technologies and ATM procedures are evolving in many important ways. professionals need to understand emerging CNS technologies and associated ATM improvements and how they impact airport and airspace operations.
CIVIL AVIATION SET UP IN INDIA
CNS FACILITIES Communication Facilities. Navigation Facilities. Surveillance Facilities.
COMMUNICATION Communication refers to sending, receiving and processing of information by electronic means.
COMMUNICATION FACILITIES Communication Facilities:
VHF AIR TO GROUND VOICE COMMUNICATION The electromagnetic waves whose frequency is with in the band 30MHz to 300MHz are defined as Very High Frequency (VHF) radio waves. VHF communication is particularly suitable for mobile applications, as these frequencies are not affected by atmospheric noise.
VHF TRANSMITTERS A transmitter uses an oscillator to produce the desired radio frequency current. Crystal-Controlled oscillators are normally employed to provide better frequency stability. Thinner the crystal, higher will be the operating frequency.
VHF TRANSMITTER The DT100 equipment can operate in the 108 to 156 MHz frequency band.
OPERATING STATES ON Line state :If the AF line port, located onto the ALB-x rear panel, is used to manage the AF + signaling connection OFF line state :if the microphone connector, located onto the control panel front side, is used to manage the AF+ signaling connection
VHF RECEVIER The VHF RX has the function of selecting the desired signal at vhf frequencies from all the other unwanted signals, amplifying and demodulating it, and reproducing it in the actual shape / desired manner.
VHF RECEIVER The DR100 equipment can operate in the 108 to 156 MHz frequency band.
OPERATING STATES ON Line state if the AF line port, located onto the ALB-S rear panel, is used to manage the AF + signaling connection. OFF Line state if the Microphone connector, located onto the Control Panel front side, is used to manage the AF+ signaling connection
DSCN D- DEDICATED S- SATELLITE C- COMMUNICATION N- NETWORK
PURPOSE OF DSCN TO PROVIDE SECURITY. TO REDUCE MANPOWER. IT IS ECONOMICAL.
VOICE COMMUNICATION SYSTEM Voice communication system is a switching system which connects the various Air traffic controller positions to various Air-to-ground and Ground-to-ground communication systems. Voice switching and routing between the (A/G and G/G) communication systems and air traffic controller working positions is done using advanced microprocessor and DSPs
AMSS AMSS stands for Automatic Message Switching System. The AMSS works on the principle of “Store and Forward”. The AFTN (Aeronautical Fixed Telecommunication Network ) is a works wide system of aeronautical fixed circuits provided for the exchange of massages and or digital data between aeronautical fixed stations.
Navigation is the 'ART' of determining the position of an aircraft over earth's surface and guiding its progress from one place to another.
To accomplish this ART, some sort of 'aids' are required by the PILOTS.
In the twentieth century, electronics also entered in the Aviation field. Direction finders and other navigational aids enabled the navigators to obtain 'Fixes' using electronic aids only. Hence such aids became more and more popular and came into extensive use.
It is a type of radio navigation system for aircraft. VORs broadcast a VHF radio signal encoding both the identity of the station and the angle to it, telling the pilot in what direction he lies from the VOR station, referred to as the radial.
It operates in the VHF band of 112-118 MHz, used as a medium to short range Radio Navigational aid. It works on the principle of phase comparison of two 30 Hz signals
There are two types of VOR, namely, conventional VOR (C-VOR) and Doppler VOR (D-VOR).
PURPOSES OF VOR
The main purpose of the VOR is to provide the navigational signals for an aircraft receiver, which will allow the pilot to determine the bearing of the aircraft to a VOR facility.
VOR enables the Air Traffic Controllers in the Area Control Radar (ARSR) and ASR for identifying the aircraft in their scopes easily. They can monitor whether aircraft are following the radials correctly or not.
VOR located outside the airfield on the extended Centre line of the runway would be useful for the aircraft for making a straight VOR approach.
PURPOSE OF VOR
VOR located enroute would be useful for air traffic 'to maintain their PDRS (PRE DETERMINED ROUTES) and are also used as reporting points.
VORs located at radial distance of about 40 miles in different directions around an International Airport can be used as holding VORs for regulating the aircraft for their landing in quickest time.
DISTANCE MEASURING EQUIPMENT
Distance Measuring Equipment is a vital navigational Aid, which provides a pilot with visual information regarding his position (distance) relative to the ground based DME station.
The facility even though possible to locate independently, normally it is collocated with either VOR or ILS.
The DME can be used with terminal VOR and holding VOR also.
DME can be used with the ILS in an Airport; normally it is collocated with the Glide path component of ILS.
The Search mode is automatically established whenever the airborne equipment is tuned to a new DME ground Transponder
When the aircraft's transmitter is in Search mode, it transmits interrogations at a higher rate (about 150 interrogations per second). When the aircraft receives at least 65% replies to its interrogations Lock-on will be established.
MODES OF OPERATION TRACK MODE:
The transmitter changes to the Track mode of operation. This process may take up to 30 seconds. Only when this is achieved, the cockpit readout of the DME range is turned on.
In the Track mode the aircraft's interrogation rate reduces considerably (about 30 interrogations per second). The reduced interrogation rate of transmission in the track mode will allow more aircraft to use the DME station.
APPLICATION OF DME
Provide continuous navigation fix (in conjunction with VOR).
Permit the use of multiple routes on common system of airways to resolve traffic.
Permit distance separation instead of time separation between aircraft occupying the same altitude facilitating reduced separation thereby increasing the aircraft handling capacity.
Provide DME distance in lieu of fan marker beacons and radio range intersections in connection with instrument approaches and holding operations respectively.
INSTRUMENT LANDING SYSTEM
The Instrument Landing System (ILS) provides a means for safe landing of aircraft at airports under conditions of low ceilings and limited visibility.
The use of the system materially reduces interruptions of service at airports resulting from bad weather by allowing operations to continue at lower weather minimums.
The ILS also increases the traffic handling capacity of the airport under all weather conditions.
INSTRUMENT LANDING SYSTEM
The function of an ILS is to provide the PILOT or AUTOPILOT of a landing aircraft with the guidance to and along the surface of the runway.
This guidance must be of very high integrity to ensure that each landing has a very high probability of success.
The basic philosophy of ILS is that ground installations, located in the vicinity of the runway, transmit coded signals in such a manner that pilot is given information indicating position of the aircraft with respect to correct approach path.
INSTRUMENT LANDING SYSTEM
The three parameters which are essential for a safe landing are: 1. Azimuth Approach Guidance.
2. Elevation Approach Guidance. 3. Range from the touch down point.
These are provided to the pilot by the three components of the ILS :
Human machine interface system, including tower consoles, ATS.
Radars are employed throughout the world for the purpose of safely controlling air traffic en-route and in the vicinity of airports.
Aircraft as well as vehicular traffic at large airports are monitored by means of high-resolution radar.
Radar has also been used to guide aircraft to a safe landing in bad weather.
AIR TRAFFIC CONTROL SYSTEM This is a system rendered between the Air Traffic Control Institutions and the aircraft to secure the safety and the mobility of aircraft by providing ground navigation or advice, information about aircraft and the airport weather condition.
HAND HELD METAL DETECTOR It is used to find the particular part of the body at which any metal or other related particle is there. It operates with chargeable battery system.
DOOR FRAME METAL DETECTOR. Every passengers has to go through this frame when any metal particle is possessed by passengers. It gives indication with both visual and audio aid.
X-RAY BAGGAGE INSPECTION SYSTEM This system has a single X-ray source sending out X-rays, typically in the range of 140 to 160 kilovolt peak (KVP). KVP refers to the amount of penetration an X-ray makes. The higher the KVP, the further the X-ray penetrates. After the X-rays pass through the item, they are picked up by a detector. This detector then passes the X-rays on to a filter, which blocks out the lower-energy X-rays. The remaining high-energy X-rays hit a second detector. A computer circuit compares the pick-ups of the two detectors to better represent low-energy objects, such as most organic materials.
EXPLOSIVE TRACE DETECTOR Narcotic/Explosive Detector is used to detect the presence of any narcotics or explosive materials. It works on the principle of Ion-Mobility Spectrography. warm up period is 30 minutes. Maintenance required once in a month.