DICIEMBRE, JOHN KEVIN B.NATOC, NEHEMIAH

VOR, DME and NDB (Draft Report)

What is a VOR? Very high frequency Omni directional radio Range(VOR) is a type of short-rangeradio navigationsystem foraircraft, enabling aircraft with a receiving unit to determine their position and stay on course by receiving radio signals transmitted by a network of fixed groundradio beacons. Also it is the standard air navigation systems in the world.VOR components: VOR Radio Station NAV 1 Radio VOR 1 GaugeVOR indicator components:I. Omni Bearing Selector (OBS) turns the compass cardII. Course Deviation Indicator (CDI) the VOR needle, centered when on the selected course and deflected left or right when off courseIII. To/From flag - indicates whether the selected course would take the aircraft toward or away from the VORIV. On/Off indicator or flag indicates whether or not you are receiving a reliable signal (A red and white flag on the Cessna and a red X on the Lear HSI) Operation:i. VOR uses frequencies in thevery high frequency(VHF) band from 108 to 117.95MHzii. VORs are commonly described as broadcasting 360 separate radials emanating from the station in all directionsiii. VORs broadcast 2 signals- the reference (or 360-N) signal and the rotating signal.iv. If the two signals are in phase the aircraft is on the 360 radial, if the receiver detects these signals are out of phase by then the aircraft is located on the 90 radial from the station and so on.Uses of VOR: VOR is used for orientation and position determination navigation by tracking to or from a station as a holding fix as soon as non precision instrument approach.

What is a DOM? Distance Measuring Equipment (DME) is a system that is used for aviation for navigation purposes.DOM components: Interrogator on board on aircraft DME station on the groundOperation:i. DME operates in the 960 1215 MHz bandii. Interrogator transmits a center frequency of 1025 up to 1150 MHziii. DME station replies on a frequency that is 63 MHz lower or 63 MHz higheriv. Interrogator uses unique pairs of pulse and same paring for the replyv. Interrogator uses to differentiate the answer from other answers send by DME station What is VOR/DME? It refers to combinedradio navigationstation for aircraft, which consists of tworadio beacons, placed together, aVHF omnidirectional range(VOR) anddistance measuring equipment(DME). VOR produces an angle between the station and the receiver in the aircraft, while DME does the same for range. Together, they provide the two measurements needed to produce a navigational "fix" using achartVOR/DME Design Description Control room is designed to be placed in container, specifically made installation of major facilities as well as devices ensure appropriate climate conditions inside control room. Facilities placed in control room include RMA cabinet, RMD cabinet, and input panel. Facilities that ensure normal operation conditions of VOR/DME and operational staff, consists of air conditioner, two heaters and five lighting lamps.

RMA cabinet is designed in standard case. On a right-hand sidewall of the cabinet on the outside HF amplifier channel is placed, covered by protective casing. Cabinet has six equal compartments. In the first lower compartment two rectifiers are placed, in the other compartments sections with guides are placed, in which cut-in cells represent functional units are installed. RMD cabinet is made in standard case. On a right-hand sidewall of the cabinet on the outside all devices that form power amplifier and HF channel are placed, covered by protective casing. Cabinet has six standard compartments by its height, where all functional units are installed.VOR/DME Technical Specifications VOR/DME Basic parameters and technical specifications meet to ICAO requirements and recommendations: In VOR (RMA) and DME (RMD) cabinets 100% "cold" equipment backup is stipulated for generation of modulating signals, modulation and amplification facilities, HF channel, and signal check and control facilities.Transition to standby facilities is automatic.What is an NDB? A NDB orNon-Directional Beaconis a ground-based, low frequency radio transmitter used as an instrument approach for airports and offshore platforms.NDB ground station components: Beacon Transmitter Antenna Tuning Unit Antenna Operation:i. NDB transmits an Omni-directional signal to be received by the Automatic Direction Finder (ADF)ii. The pilot uses the ADF to determine the direction to the NDB relative to the aircraftiii. To navigate using the ADF, the pilot enters the frequency of the NDB and the compass card (or arrow) on the ADF will indicate the heading to the station. The signal is transmitted on an uninterrupted 24/7 basisiv. NDBs typically operate in the frequencyrange from 190kHz to 535kHz (although they are allocated frequencies from 190 to 1750kHz)v. transmit a carriermodulatedby either 400 or 1020Hzvi. NDB radiators are vertically polarisedvii. NDBantennasare usually too short forresonance at the frequency they operate typically perhaps 20m length compared to a wavelength around 1000mUses of NDBs: AirwaysNDB bearings provide a charted, consistent method for defining paths aircraft can fly FixesNDB are used by aircraft navigators and previously mariners to help obtain a fix of their geographic location on the surface of the Earth Instrument landing systems NDBs are most commonly used as markers or "locators" for an instrument landing system(ILS) approach or standard approach.NDB Adverse Effects: Night effect: radio waves reflected back by the ionosphere can causesignal strength fluctuations30 to 60 nautical miles (54 to 108km) from the transmitter, especially just before sunrise and just after sunset (more common on frequencies above 350kHz) Terrain effect: high terrain like mountains and cliffs can reflect radio waves, giving erroneous readings; magnetic deposits can also cause erroneous readings Electrical effect: electrical storms, and sometimes also electrical interference (from a ground-based source or from a source within the aircraft) can cause the ADF needle to deflect towards the electrical source Shoreline effect: low-frequency radio waves will refract or bend near a shoreline, especially if they are close to parallel to it Bank effect: when the aircraft is banked, the needle reading will be offsetDifference between VOR and NDB: an NDB is a Non Directional Beacon - it emits a radio signal in all directions providing no course guidance, but enables a receiver to detect it and with an indicator containing a pointer, enable the signal to be 'homed in' on, so one can track right to the location of the ground based transmitter.

A VOR is: a Very High Omni Range transmitter, which sends out a signal in all directions as well, but also, has 360 individually selectable radials (courses), which permits a VOR receiver to detect them. Then, using an indicator with 360 selectable courses, allow the operator to select an individual course (referenced to magnetic North) and actually track the course selected, as well as have 'TO' and 'FROM' information displayed via a flag, so the navigator can track a specified course, both TO and FROM the ground based radio transmitter, while actually knowing his position relative to the transmitter.References: http://www.southernavionics.com/blog/bid/50999/What-is-an-NDB-or-Non-Directional-Beacon http://www.lewisaire.com/training/VOR-1.html#below http://www.flightsimaviation.com/aviation_theory_21_VOR_Navigation_part_1.html http://www.skybrary.aero/index.php/Non-Directional_Beacon http://www.telecomabc.com/d/dme.html http://www.azimut.ru/en/catalogue/navigation/vordme