ELEC 4600

RADAR & NAVIGATION

Lecturer: R. Edwards

COURSE OUTLINE

RADAR & NAVIGATION

• Engineering is Applied Science

• Many areas of science and mathematics are applied to solve the problems associated with Radar and Navigation

RADAR & NAVIGATION

• Some examples are:– Antennas– RF circuit design– Plane geometry– Spherical geometry– Probability and statistics– DSP – discrete-time signal processing– Orbital mechanics– Matrix algebra

NAVIGATION

• The first half of the course will cover NAVIGATION, in particular,

• aircraft navigation

NAVIGATION

• The science of determining the position of a vehicle relative to the position of its destination

NAVIGATIONCourse Outline (1)

• Basic Information– Units and Conventions

– Lines of Position and Position Fixes – Geometry

– Requirement for air navigation systems

• Relative Navigation Systems– NDB/ADF (Non-Directional Beacon/Automatic Direction Finder)

– VOR (VHF Omnirange)

– TACAN

– DME

• Absolute Navigation Systems– Multi-DME

– LORAN-C

– GPS

– INS

• Navigation Fundamentals– Position Fix Transformations

– Dead-Reckoning Calculations

– Most Probable Position Calculations

– Course Line Computations

NAVIGATIONCourse Outline (2)

Navigation

Organizational Framework

(The players in the game)

• International – ICAO

• National – FAA/Nav Canada, Transport Canada/CAA

• Industry – ARINC/RTCA

International• ICAO (International Civil Aviation Organization)

• An organization of the United Nations

• Responsible for recommending standards for civil aviation systems and procedures

•(SARPs STANDARDS AND RECOMMENDED PROCEDURES)

• NOTE: Responsibility for implementation rests with individual countries.

Countries may elect not to follow recommended procedures and if they do so will file an exception

National• USA - FAA• Canada – Transport Canada and Nav Canada

• Transport Canada (government)– Develops and Enforces Rules and Regulations

• Nav Canada (not-for profit)– Installs/maintains navigation aids and air traffic radars– Operates air traffic control system

Industry• ARINC (Aeronautical Radio Incorporated)

– Develops standards for interchangeability of avionics equipment

• Equipment chassis, mounting racks and and connectors (ATR

• Digital Data bus standards (ARINC 429, 469)

Industry• RTCA (Radio Technical Committee for

Aeronautics)

– Made up of representatives from avionics and airline industries and government agencies

– Develops functional specifications for avionics equipment

• NOTE: FAA usually uses RTCA documents form basis of certification of equipment

NAVIGATIONUnits and Conventions

• Distance: Nautical Mile (NM) = 1832m exactly

• Speed: Knot (kt) – 1 NM/hour

• Angle: degrees measured Clockwise from North and is always expressed as three digits e.g. 090, 006. Note: zero is pronounced zero

North• Two main North references:

– True (T) : the geographical North Pole(the point at which the earth’s spin axis intersects the earth’s surface in the Northern hemisphere)

– Magnetic (M) : the North magnetic pole

– VARIATION is the differencebetween True and Magnetic North

NorthConversion from Magnetic to True and Vice Versa

Variation is usually given as West or East depending on whether the Magnetic Pole appears to be West or East of the True Pole

East Variation is considered positive (+)

True direction = Magnetic direction + Variation

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Magnetic and True North

VARIATION

TRUE

MAG

Pole Migration

Units and Conventions (Continued)

• Heading: The angle between the longitudinal axis of a vehicle and the North reference (can be either Magnetic or True)

• Relative Bearing: The angle between the longitudinal axis of the vehicle and a line joining the vehicle and the point in question

Units and Conventions

NavigationLines of Position

NavigationPosition Fix

NavigationPosition Fix Geometry

Requirements for an Air Navigation System

Accuracy(Allowable Error)

Integrity

Availability

Continuity

These all depend on the phase of flight

Phases of Flight• Enroute – least restrictive

– Usually at cruising altitude - no obstaclesstable situation, no conflicting traffic

• Terminal Area – more restrictive– Lower altitude – possible obstacles

less stable situation, probable conflicting traffic

• Approach and Landing – most restrictive– Very low altitude – obstacles present

– on collision course with the ground - must make sure it is the runway!!

Accuracy

• Two main types of ERROR– Flight Technical Error

The difference between the actual position of the aircraft and the

– System Error

Requirements for Accuracy (95%)

• Enroute– 12.4NM (Oceanic), 2.0 NM (Continental)

• Terminal Area– 0.4 NM

• Landing– Category I

(Limits of 200Ft ceiling and ½ NM visibility)– 16. m laterally and 8 m vertically

Integrity• The ability of the system to warn the pilot when an

out-of-tolerance condition is detected

• Enroute– 5 minutes

• Terminal Area– 30 seconds

• Landing– Category I - 6 seconds– Category II and III – 1 second

Availability• The probability that the required navigation

is usable

• All Modes– .99 to .99999

Continuity

• The probability that the required navigation is available for the duration of a procedure once the procedure has been started

• Enroute/Terminal– 10-5/hr

• Landing– 10-6/15sec (Cat I)