DME DISTANCE MEASURING EQUIPMENT Operati(1)

Warsaw University of Technology
Faculty of Power and Aeronautical Engineering
A REPORT ON DME - DISTANCE
MEASURING EQUIPMENT
Operating Principle, Description and Error Analysis

ANS637 Attitude and Navigation System DME, its principle of operation, description of selected type
and error analysis
1
DME (Distance Measuring Equipment) – Principle of operation,
description of selected type and error analysis
Course Title -
ANS647 - Attitude and Navigation System
Report submission by –
Sultan Mahmood Mukut
Index: 302613, Semester II, Winter 2018, MEiL, WUT
Submitted to –
Janusz Gajda
Senior Lecturer, Department of Automation and Aeronautical Systems, MEiL
Warsaw University of Technology
Warsaw, 18th January, 2019

ANS637 Attitude and Navigation System DME, its principle of operation, description of selected type
and error analysis
2
List of Symbols and Derivations
DME Distance Measuring Equipment
GPS Global Positioning System
ARNS Aeronautical Radio Navigation System
ATC Air Traffic Control
VHF Very-High Frequency
UHF Ultra-High Frequency
FIR Flight Information Region
INS Inertial Navigation System
NAVAID Navigational Aid
ICAO International Civil Aviation Organization
TACAN Tactical Air Navigation
IFF Identification friend or foe
VOR VHF Omnidirectional Range
ADF Automatic Direction Finding
ILS Instrument Landing System
SSR Secondary Surveillance Radar
FAA Federal Aviation Administration
VFR Visual Flight Rules
IFR Instrument Flight Rules
VOR/DME VHF Omnidirectional Range and Distance Measuring Equipment
VORTAC VHF Omnidirectional Range and Tactical air navigation system
ILS/DME Instrument Landing System and Distance Measuring Equipment
LOC/DME Localizer and Distance Measuring Equipment
LORAN Long Range Navigation
MHz Megahertz
≤ less or equal
± plus-minus
ε Epsilon
Σ Sigma
 Theta

ANS637 Attitude and Navigation System DME, its principle of operation, description of selected type
and error analysis
3
TABLE OF CONTENTS
TITLE PAGE
Chapter 1 Introduction 4
Introducing DME 4
Background and Early Development 5
Installation and components of DME 6
Chapter 2 Principle of Operation of DME 8
Working Principle of DME 8
Chapter 3 Description and selected type of DME 11
Interrogator - DME Onboard Aircraft 11
Transponder - DME installed on Ground Station 12
Chapter 4 Discussion of Error Analysis 14
Assumption of the problem and best approximation 14
Chapter 5 Concluding Remarks 16
List of References 17

ANS637 Attitude and Navigation System DME, its principle of operation, description of selected type
and error analysis
4
Chapter 1: Introduction
Introducing DME
In the last hundred years for the first time in the history of mankind we observed the
technological advancement at a rate so fast that is unprecedented and exemplary compared to
the progress of previous centuries. The most vital tool of any civilization, communication has
existed since the very beginning of human history but it was not until the last century that
scientists and engineers began to study the science behind it.
Development of navigation system, information theory, mass communication
progressed enormously as people started commuting and travelling more from one place of
earth to another. As with the advancement of respective fields of technology we saw the
fascinating development in the field of radio navigation technology as well. Today a world so
connected and alert is quite unthinkable without air transportation system. As the science and
engineering of aeronautics and aerospace progressed so did the advancements of avionics and
space communication system. GPS, and satellite communication revolutionized the mode of
technology.
Today we see the rapid growth of privatization, commercialization and militarization
of Aircrafts and Spacecrafts. And with this increasing number it is inevitably crucial to know
the position, location and orientation of each and every flying machine functioning in the world
continuously. And to do that it is fundamental to measure and calculate the distance between
the traffic controller station and the moving object, basically all the time. Luckily, we have
developed the technology to do that instantly.
This brings us to the topic of our report that is, DME. The full meaning of DME stands
for Distance Measuring Equipment. From the elaboration of the abbreviation we get the
general sense about the device. DME is a form of radar used by all kinds of aircrafts and is
extensively used for navigation purposes. Basically, DME is an Aeronautical Radio Navigation
System, which helps to determine the distance between an airplane and a ground station. In
other word DME is like a secondary radar system that provides an aircraft’s flight crew with
direct, continuous visual indication of distance from a selected ground station, which is situated
at a known geographical location.