Navigation and Radio Navigation Lecture Notes

NAVIGATION GENERAL/RADIO NAVIGATION VFR/IFR COMMUNICATIONS

  • Prepared by: Mok T K

  • Prepared for: Singapore Polytechnic School of Mechanical and Aeronautical Engineering

Navigation Coordinates and Airspace Information

  • Coordinates indicating significant airspace points, users should refer to the navigation map for details.

    • Points:

    • Point Alfa: 01°30'33" N, 103°49'42" E

    • Sembawang: 01°30'33" N, 103°49'42" E

    • Seletar: 01°28'30" N, 103°49'54" E

    • Other reference points indicated (PU R-263/D-5.9, R-296, etc.)

  • Airspace Details: 50000 ft (FL500) soon shall be standard, with altitude management up to at least 4,500 ft.

    • Altitude restrictions in various locations and airspaces.

General Knowledge about Earth

  • Shape of Earth: Oblate spheroid, polar diameter is approximately 23 nautical miles or 43 km less than the equatorial diameter.

  • GPS Systems:

    • World Geodetic System 1984 (WGS 84)

    • UK Ordnance Survey 1936 (OS36)

    • Nouvelle Triangulation de France (NTF)

    • European Datum 1950 (ED50)

  • Poles: Extremities of the axis about which the Earth spins, the Earth orbits the sun at an angle of 23.5°.

  • Cardinal Points: North (N), South (S), East (E), West (W)

  • Quadrantal Directions: Northeast (NE), Southeast (SE), Southwest (SW), Northwest (NW)

Circles of the Earth

  • Great Circle: A circle on the earth with the center and radius being those of the earth itself; it is the shortest distance between two points on earth.

  • Equator: Divides the Earth into two equal hemispheres, serves as a reference datum for latitude.

  • Meridians: Great circles joining the North and South Pole, equivalent to the Y-axis in a Cartesian system (e.g., Greenwich Meridian).

  • Parallels of Latitude: Small circles that run parallel to the equator, indicating position north or south of the equator.

Rhumb Line

  • A regularly curved line on the Earth's surface that crosses all meridians at the same angle, maintaining a constant direction. Distinctly thinner on Mercator projections compared to great circles.

    • Examples of Lines:

    • Equator

    • Any Meridian

    • Latitudes are NOT great circles.

Maps and Accuracy

  • Typical Applications of navigation data:

    • 5321N (1 NM = 6080 feet)

    • Various accuracies are outlined in the table for flight navigation from high-level hops to precise navigation for navaids.

    • Formats for reporting location:

    • 53°21'17"N for airfield charts

    • 53°21'17.3"N for precise navaid location

Variation, Magnetic Dip, and Deviation

  • Magnetic Dip:

    • Refers to the angle of a compass needle from the horizontal, influenced by the Earth's magnetic field. Maximum dip occurs when the aircraft is at the magnetic pole, causing errors in turning and acceleration.

  • Deviation:

    • Angle between the direction indicated by the compass needle and magnetic north, affected by local magnetic influences, e.g., metal or electrical currents.

  • Variation:

    • Angular difference between true north and magnetic north, measured in degrees, changes over time due to geological and atmospheric conditions.

Navigation Illustrations and Symbols

  • A multitude of navigational aids is represented in illustrated diagrams.

    • Symbols include:

    • NDB (Non-Directional Beacon)

    • VOR (VHF Omnidirectional Range)

    • ILS (Instrument Landing System)

    • DME (Distance Measuring Equipment)

    • Air Traffic Control phrases for emergencies (Mayday/Pan-pan)

VFR/IFR Definitions

  • VFR: Visual Flight Rules, implies flying with visual reference to the terrain.

  • IFR: Instrument Flight Rules, implies flying primarily by reference to instruments, regardless of visibility.

Communications Standards in Aviation

  • Proper communication techniques must be adhered to, including standard phraseology and phonetic spelling.

    • Time format: Uses Zulu time, standard amongst aviation communications.

    • Language: English predominantly used worldwide.

Weather Information in Navigation

  • Sources:

    • ATIS: Aerodrome Terminal Information Service, recurrent updates on weather and operational runways.

    • VOLMET: Regional weather reports transmitted over HF voice frequencies.

    • ATC: Air Traffic Control can provide localized weather information.

Handling Equipment Failures and Emergencies

  • Protocols exist for equipment malfunctions, with distress signals outlined (Mayday for emergencies, Pan-pan for urgencies).

Radio Propagation

  • Describes how ground and airborne communication can be impaired by various conditions, the range and effects are calculated based on aerial heights above mean sea level.

    • Transmission ($Tx$): Direct waves and ground reflected waves; Reception ($Rx$): Height of ground aerial and aircraft altitude.

    • Propagation formula:
      R=1.23(ext√h<em>1+ext√h</em>2)R = 1.23( ext{√}h<em>1 + ext{√}h</em>2)

    • Where:

    • $h_1$ is the height of the ground aerial in feet AMSL.

    • $h_2$ is the aircraft altitude in feet AMSL.

Conclusion

  • This document serves as a foundational component for students of navigation, offering insight into key terms, protocols, and the necessary standards for operating in both VFR and IFR conditions.