Air craft surveillance & instrumental landing system
Text of Air craft surveillance & instrumental landing system
1. Air Craft Surveillance & Instrumental Landing System Bikas Chandra Sadashiv ECE I GNIT 3rd Year
2. Air Craft Surveillance Through RADAR 3. Introduction RADAR Frequencies RADAR Applications Types of RADAR Topics To Be Covered 4. Introduction RADAR is stand for Radio Detection And Ranging and was developed prior to World War II. Today RADAR is extremely important in civil aviation. It is used by ATC to monitor and control numbers of aircrafts in airspace as well as by pilot for weather warning and navigation. 5. Radar Frequencies Radar operates on UHF and SHF - Super High Frequency (1 GHz - 30 GHz). RADAR systems are in SHF bands because: a) These frequencies are free from disturbance. b) Higher frequency, shorter wavelength, RADAR more effective.(shorter wavelengths are reflected more efficiently.) 6. RADAR Applications RADAR has a wide range applications including 1. Ground RADAR : extensively used by Air Traffic Control to separate aircrafts. 2. Airborne Weather RADAR: used by pilots. It provide pilots with information regarding weather ahead. 7. Types of RADAR (RSR) En-Route Surveillance Radar TAR- Terminal Approach Radar (PSR & SSR) SMR (Surface Movement Radar) Classifications of RADAR 8. 1) En-Route Surveillance Radar (RSR) En-Route Surveillance Radars (RSR) are long range radars which the signal goes to 300 NM. It operates with frequency between 1 to 2 GHZ. It used for airway surveillance to provide range and bearing of aircraft. **Surveillance: close observation, especially of a suspected spy or criminal. 9. 2) Terminal Approach Radar (TAR) TAR is a high definition radio detection device which provides information on identification, air speed, direction and altitude of aircraft to assist air traffic controllers to track the position of aircraft in the air within the vicinity of the airport. This radar gives the air traffic controller a better or true picture of all aircraft flying in his control zone. 10. 2) Terminal Approach Radar (TAR) PSR SSR 11. Working of PSR : Primary Surveillance Radar (PSR) transmits a high power signal. When a signal strikes an object or target, some signal energy is reflected back and is received by the radar receiver. RADAR receiver will plot the direction and the distance of the target (aircraft) from the radar station. Thus, the ATC could know the position of aircraft. through the RADAR display. Primary Surveillance Radar (PSR) 12. Primary Surveillance Radar (PSR) Antenna Transmitted Pulse Target Cross Section Propagation Reflected Pulse (echo) Radar observable: Target range Target angles (azimuth & elevation) Target size (radar cross section) Target speed (Doppler) 13. Secondary Surveillance Radar (SSR) Working of SSR : Secondary Surveillance Radar (SSR) transmits an interrogation signal which is received by the target aircraft. The aircraft transponder sends back a coded reply to the ground radar equipment. From the coded signal, information of the aircrafts call sign, altitude, speed and destination. SSR requires an aircraft to be fitted with transmitter/receiver called as 14. How SSR Works? The ground secondary radar transmits 1030MHz signal. The aircraft radar receives on 1030MHz and transmits back 0n 1090MHz. The transponder reply is more powerful than the 15. 3) Surface Movement Radar (SMR) SMR installed at airport (at top of ATC tower building) to provide a very accurate radar display in all weathers and conditions of visibility. (operate with frequency 18- 40Ghz) SMR radar display can show all of airfield infrastructure including aircraft movements on runway, taxiway and apron. It is designed to provide clear display of all aircraft on runway or taxiway so that ATC can ensure runway are clear for take- off/landing and also guide aircraft to apron 16. 3) Surface Movement Radar (SMR) 17. RADARS USED IN ATC Airport Surveillance Radar (ASR) Air Route Surveillance Radar (ARSR) Airport Surface movement Detection Equipment (ASDE)/Advanced Surface Movement Guidance & Control System (ASMGCS) Precision Approach Radar (PAR) Mono-pulse Secondary Surveillance Radar (MSSR) 18. INSTRUMENT LANDING SYSTEM (ILS) 19. Introduction The Uses of ILS ILS Components How Localizer Works How Glide Path Works Marker Beacons Topics To Be Covered 20. INTRODUCTION Radio beam transmitter that provides a direction for approaching aircraft that tune their receiver to the ILS frequency 21. The Uses of ILS To guide the pilot during the approach and landing. Very helpful when visibility is limited To provide an aircraft with a precision final approach. To provide an aircraft guidance to the runway both in the horizontal and vertical planes. 22. ILS Components ILS consists of Ground Installations and Airborne Equipments There are 3 equipments for Ground Installations, which are: 1. Ground Localizer (LLZ) Antenna To provide horizontal navigation 2. Ground Glide path (GP) Antenna To provide vertical navigation 3. Marker Beacons To enable the pilot cross check the aircrafts height. There are 2 equipments for Airborne Equipments, which are: 1. LLZ and GP antennas located on the aircraft nose. 2. ILS indicator inside the cockpit 23. Localizer Localizer is the horizontal antenna array located at the opposite end of the runway. Localizer operates in VHF band between 108 to 111.975 MHz 24. Transmit two signals which overlap at the centre. The left side has a 90 Hz & right has a 150 Hz modulation. The overlap area provides the on-track signal. Right Left How Localizer Works 25. Localizer Needle indicates direction of runway. Centered Needle = Correct Alignment 26. Glide Path Antenna Array Glide Path is the vertical antenna located on one side of the runway about 300 m to the end of runway. Glide Path operates in UHF band between 329.15 and 335 MHz 27. How Glide Path Works Glide path produces two signals in the vertical plane. The upper has a 90 Hz modulation and the bottom has a 150 Hz modulation. 28. Glide Path Needle indicates above/below glide path. Centered Needle = Correct Glide path 29. Marker Beacons Marker beacons operating at a carrier frequency of 75 MHz are provided. When the transmission from a marker beacon is received it activates an indicator on the pilot's instrument panel. The correct height the aircraft should be at when the signal is received in an aircraft. 30. Runway Approach Non-Instrument Runway (NI) Non-Precision Runway (NP) Precision Runway (P) Threshold Touchdown zone Aiming point 31. Types of Runway Approach 1.Non-Instrument Runway (NI) A runway intended for the operation of aircraft using visual approach procedure 2. Instrument Runway A runway intended for the operation of aircraft using instrument approach procedures a) Non-Precision Runway (NP) An instrument runway served by visual aids and a non-visual aid providing at least lateral guidance adequate for a straight-in approach b) Precision Runway (P) Allow operations with a decision height and visibility 32. How ILS works? Ground localizer antenna transmit VHF signal in direction opposite of runway to horizontally guide aircraft to the runway centre line. Ground Glide Path antenna transmit UHF signal in vertical direction to vertically guide aircraft to the touchdown point. Localizer and Glide Path antenna located at aircraft nose receives both signals and sends it to ILS indicator in the cockpit. These signals activate the vertical and horizontal needles inside the ILS indicator to tell the pilot either go left/right or go up/down. By keeping both needles centered, the pilot can guide his aircraft down to end of landing runway aligned with the runway center line and aiming the touch down.