years. Such a rich environment has enabled me to develop a wide variety of classes and research efforts that these writings draw upon. Thanks also goes to Neil Gerein and Jerry Freestone from NovAtel, Dave Brooks from Sensor Systems, James Horne from Roke, and Herbert Blaser from u‐blox for providing antenna information.
About the Authors
Mohinder S. Grewal, Ph.D., P.E., is well known for his innovative application of Kalman filtering techniques to real world modeling problems and his ability to communicate this complex subject to his students. His original research appears in IEEE and ION refereed journals and proceedings. He holds patents in GUS clock steering and L1/L5 differential bias estimation. Dr. Grewal is Professor of Electrical Engineering at California State University, Fullerton, which awarded him its 2008-2009 Outstanding Professor Award. His consulting associations include Raytheon Systems, Boeing Company, Lockheed‐Martin, University of California, Riverside, staff of the US Department of the Interior, Geodetics, and Northrop. He is a Senior Member of IEEE and member of the Institute of Navigation. His Ph.D. in Control Systems and Computers is from University of Southern California.
Angus P. Andrews derived the first electrostatic bearing torque parametric models for calibrating electrostatic gyroscopes in 1967 at the Autonetics Division of Rockwell International, and then saw its development through two generations of strapdown inertial navigation systems to the N73 competitor for the US Air Force Standard Navigator. His career in inertial navigation also included derivations of new square root filtering formulas. His undergraduate degree is from MIT and his Ph.D. in mathematics is from University of California, Los Angeles.
Chris G. Bartone, Ph.D., P.E., is a professor at Ohio University with over 35 years experience in communications, navigation, and surveillance systems. He received his Ph.D., E.E. from Ohio University, M.S.E.E. from the Naval Postgraduate School, and B.S. E.E. from The Pennsylvania State University. Dr. Bartone has developed and teaches a number of GNSS, antenna, and microwave classes. He is a recipient of the RTCA William E. Jackson award, the ION Captain P.V.H. Weems award, and is a Fellow of the ION. His research concentrates on all aspects of navigation systems.
About the Companion Website
This book is accompanied by a companion website:
The website includes:
Solution Manual for Instructors only
MATLAB files for selected chapters
Appendices B and C
1 Introduction
A book on navigation? Fine reading for a child of six!1
1.1 Navigation
During the European Age of Discovery, in the fifteenth to seventeenth centuries, the word navigation was synthesized from the Latin noun navis (ship) and the Latin verb stem agare (to do, drive, or lead) to designate the operation of a ship on a voyage from A to B – or the art thereof.
In this context, the word art is used in the sense of a skill, craft, method, or practice. The Greek word for it is τεχνυ, with which the Greek suffix ‐λoγια (the study thereof) gives us the word technology.
1.1.1 Navigation‐Related Technologies
In current engineering usage, the art of getting from A to B is commonly divided into three interrelated technologies:
Navigation refers to the art of determining the current location of an object – usually a vehicle of some sort, which could be in space, in the air, on land, on or under the surface of a body of water, or underground. It could also be a comet, a projectile, a drill bit, or anything else we would like to locate and track. In modern usage, A and B may refer to the object's current and intended dynamic state, which can also include its velocity, attitude, or attitude rate relative to other objects. The practical implementation of navigation generally requires observations, measurements, or sensors to measure relevant variables, and methods of estimating the state of the object from the measured values.
Guidance refers to the art of determining a suitable trajectory for getting the object to a desired state, which may include position, velocity, attitude, or attitude rate. What would be considered a “suitable” trajectory may involve such factors as cost, consumables and/or time required, risks involved, or constraints imposed by existing transportation corridors and geopolitical boundaries.
Control refers to the art of determining what actions (e.g. applied forces or torques) may be required for getting the object to follow the desired trajectory.
These distinctions can become blurred – especially in applications when they share hardware and software. This has happened in missile guidance [1], where the focus is on getting to B, which may be implemented without requiring the intermediate locations. The distinctions are clearer in what is called “Global Positioning System (GPS) navigation” for highway vehicles:
Navigation is implemented by the GPS receiver, which gives the user an estimate of the current location (A) of the vehicle.
Guidance is implemented as route planning, which finds a route (trajectory) from A to the intended destination B, using the connecting road system and applying user‐specified measures of route suitability (e.g. travel distance or total time).
Control is implemented as a sequence of requested driver actions to follow the planned route.
1.1.2 Navigation Modes
From time immemorial, we have had to solve the problem of getting from A to B, and many solution methods have evolved. Solutions are commonly grouped into five basic navigation modes, listed here in their approximate chronological order of discovery:
Pilotage essentially relies on recognizing your surroundings to know where you are (A) and how you are oriented relative to where you want to be (B). It is older than human kind.
Celestial navigation uses relevant angles between local vertical and celestial objects (e.g. the Sun, planets, moons, stars) with known directions to estimate orientation, and possibly location on the surface of the Earth. Some birds have been using celestial navigation in some form for millions of years. Because the Earth and these celestial objects are moving with respect to one another, accurate celestial navigation requires some method for estimating time. By the early eighteenth century, it was recognized that estimating longitude with comparable accuracy to that of latitude (around half a degree at that time) would require clocks accurate to a few minutes over long sea voyages. The requisite clock technology was not developed until the middle of the eighteenth century, by John Harrison (1693–1776). The development of atomic clocks in the twentieth century would also play a major role in the development of satellite‐based navigation.
Dead reckoning relies
