Customer Reviews

GPS Land Navigation

5 star:		(11)
4 star:		(5)
3 star:		(2)
2 star:		(0)
1 star:		(0)

 

 

The book's objective is to remove the mystery surrounding this new technology so that anyone who owns a GPS receiver can become an expert in its use. GPS Land Navigation has 6 chapters that cover everything from hardware (GPS, compass, altimeter), to software (maps, coordinates, bearings, etc.), to skills (trip planning, route finding, map reading, etc.) Three appendices contain: elevation, latitude and longitude of the highest points in each county; the coordinates of each state's capital building; and, the coordinates for the junction of every U.S. Interstate with either another U.S. Interstate or an U.S. Highway. You can enter this into a GPS receiver and use it a-priori to navigate to that specific location. The last appendix has detailed comparison information for every handheld GPS in production as of early 1997.

Chapter 1 Introduction to GPS discusses the NAVSTAR (U.S.) and GLONASS (Russian) satellite navigation systems. The NAVSTAR system includes 24 satellites and their coordinating ground stations. Each satellite carries four atomic clocks, and continuously sends radio signals, which GPS receivers use to calculate position. NAVSTAR is designed so that any location on earth will have line of sight access to at least six satellites at all times (as long as there is an unobstructed view from horizon to horizon). Simply stated, a GPS receiver determines its position by measuring the time it takes radio signals to travel from four satellites to the receiver. Each satellite simultaneously sends its precise location and software in the receiver triangulates these to get a fix. GPS receivers provide accuracy between 40 and 100 feet and chapter 1 provides an excellent discussion as to the determinants of precision and accuracy. Tidbit of information, GPS receivers are constantly updated by the atomic clocks in the GPS satellites, so as long as you have one you will know the EXACT time.

Chapter 2 GPS Hardware discusses the essential equipment needed for navigation. Surprise! GPS does not eliminate the need for traditional navigation instruments (compass and altimeter) but rather it complements them. A GPS receiver provides three essential pieces of data for backcountry land navigation: 1) position in terms of coordinates, 2) direction between any two waypoints, 3) distance between any two waypoints. This chapter gives you lots of information about how GPS receivers generate data. One piece of data that GPS receivers don't provide is actual directions on the ground. In most field applications, you need a compass to know which direction you are facing and which way to walk. Chapter 2 discusses baseplate, mirror, and sighting compasses. It explains how to obtain, set, and then follow a bearing (either from a map or a GPS). Finally, it summarizes magnetic declination, magnetic interference, and magnetic inclination. If you already know what these are, cool. If not, you'd better read the book. Finally, GPS receivers also display altitude, but for reasons discussed in Chapter 4, it isn't very accurate. So carry an altimeter and read the book on how to use it.

Chapter 3 Maps Maps are the single most important source of information in the backcountry. If you practice, you can guestimate where you are and get to another point using only a map and compass. If you plan in advance, you can navigate with only a GPS receiver and compass. However, with a topographic map, GPS, compass, and altimeter you can determine exactly where you are, plan precisely how to get anywhere with pinpoint accuracy, and even estimate how long it will take to get there. This chapter contains one of the best descriptions of maps that I have read. It covers all the classic things such as quadrangles, map-scale, distances, and various map series. Then it goes into some theory I had never really thought too much about. For example, did you know that maps and coordinate data from the continental U.S. are based on either NAD27, NAD83, or WGS84 datum? I never even knew such things existed much less why they might be important. But, you must tell your GPS receiver what datum the map you are using is based on. Chapter 3 introduces the concepts of angular (latitude/longitude) and rectangular (UTM) coordinate systems (whoa, no kidding, coordinate systems are critical) . This chapter also gives one of the most understandable descriptions (illustrated) of contour lines that I have read. There's even more. Chapter 3 tells you what all the information printed along the margins and corners of maps means. For example latitude and longitude are labeled at each of the four corners and are also tickmarked along the neatlines at 2.5 minute intervals (remember this you'll hear it again).

Chapter 4 Coordinate Systems may be a bit arcane but it's the meat of the book ("you can take the cheat or run the meat."). Simply stated, coordinate systems are the fundamental link between maps and the world they represent. Six digits of latitude and seven digits of longitude are all it takes to specify a location within 50 feet of precision anywhere on earth! A GPS receiver provide these digits. Unfortunately, merely knowing that you are at 34o35' 00" N, 084o12'30" W does not automatically translate to about a klick NNE of Cochran Falls in most peoples' minds. It does however if you grok coordinates. This chapter discusses angular coordinates and UTM rectangular coordinates in comprehensible terms (GPS receivers can be set to use either angular or UTM coordinates for navigation).

Chapter 5 Directions puts all the theory together. True North, Grid North, Magnetic North, Azimuths, Bearings, Great Circles, and Rhumb Lines all become clear and you are ready to go from anywhere to anywhere-else even if you don't know where either of them are relative to you.

Chapter 6 GPS Skills tells you how to use the theory. It explains how to use a GPS without a map, or with a map (which is what most of us do), and what to do when (horrors of horrors) your GPS receiver breaks down.

I purchased two books on GPS at the same time. This book by Ferguson and another GPS Made Easy by Letham. The Ferguson book is superior. It contains more information on maps and how different measuring systems work such as Longitude and Latitude, UTM Coordinates, and the Military Grid system. Others were also covered. It gives Long.. and Lat.. coordinates for all major highway junctions in the U.S. The tutorial on how to read maps is superior. The Ferguson book gives names and addresses of GPS manufacturers. For some reason he omitted the email addresses. Go to "GPS" on any search engine. Information an the GPS units is dated in both books. Both give a good overview of the GPS system and how it works. Both give good explainations of GPS features. Buy this book first and go from here.

I bought this book in 1999 when I first started using GPS recreationally and to record site locations. Since that time, I have looked through almost every GPS guide aimed at recreational users. This book still holds up as the best I have seen.

Its primary focus is the use of GPS as a component in land navigation. The material on topographic maps, compass navigation, datums, coordinate systems, and the possible sources of error that are unique to GPS is what makes this book more than a how-to-be-a-techie recguide. It is presented and explained in such a clear and efficient manner that this book is both a valuable resource and an interesting book to just pick up and read.

The chapter on GPS equipment is outdated, but that information can be obtained from salespeople or manufacturers' websites. The cautions and explanations regarding Selective Availability are no longer relevant, since SA was switched off in May 2000. The rest of the material is timeless and fundamental and applies to anything locational. Still, it would be good if a second edition could be written to get rid of the outdated material.

Anyone who takes the time to learn the material covered in this book will gain much more use from a GPS unit and topographic maps. You need to know more than your latitude and longitude. This book will give you the background you need in order to know what your GPS unit is telling you and how to use that information correctly.

OK, folks, here it is, April, 2002, and Ferguson's book is 5 years old with GPS technology advancing at an amazing pace... but the true value of his book isn't his discussion on the hardware - it's the absolute wealth of information about LAND NAVIGATION that makes it an enduring treasure! I have found myself coming back to it time and again over my past 4 years of ownership to dig into finer detail about the GPS system, or coordinate systems, or whatever else is associated with land nav using GPS. Despite the outdated GPS hardware commentary, the principles remain the same, and MF's treatment is superb - the measure by which others will be considered.

If you need a basic reference that ties together LAND NAVIGATION with GPS, this should be in your library (along with Bjorn Hjellstrom's classic, "Map & Compass").

73, Bob
...

Granted, I speak from the perspective of a techno-nerd, but with that having been said I rate Ferguson's book as a non-stop spellbinder. This guy answers almost all the GPS questions I've been mulling, and a lot more I hadn't even stumbled on. It's up to date, in depth, a relatively easy read, with good graphics and examples. Your companion text will have to be your own GPS's instruction manual, but Ferguson adds information about satellites, map systems, and practical use of the instrument. You can find a few internet web pages which are a bit more technical in their own narrow topics, but Ferguson really pulls it all together in a useful framework. Don't hesitate on this one.

I am amazed that none of the manufacturers of hand-held GPS equipment thought to write this book before--it's what every GPS user needs! Whether you already own or contemplate buying a GPS receiver, this book is a must. It covers all levels of expertise and is well worth the asking price. It doubles the value of your GPS receiver.

OK, folks, here it is, April, 2002, and Ferguson's book is 5 years old with GPS technology advancing at an amazing pace... but the true value of his book isn't his discussion on the hardware - it's the absolute wealth of information about LAND NAVIGATION that makes it an enduring treasure! I have found myself coming back to it time and again over my past 4 years of ownership to dig into finer detail about the GPS system, or coordinate systems, or whatever else is associated with land nav using GPS. Despite the outdated GPS hardware commentary, the principles remain the same, and MF's treatment is superb - the measure by which others will be considered.

If you need a basic reference that ties together LAND NAVIGATION with GPS, this should be in your library (along with Bjorn Hjellstrom's classic, "Map & Compass").

73, Bob

Ferguson's writing style about the technical "how tos" of GPS use is near perfect. He packs a great deal of information into the readable volume, but is very good at chunking it up and presenting it in a format where you can either read the book straight through (which I did), or use it as a reference.

I basically knew nothing about GPS or land navigation when I bought this, I know feel very confident in my ability to use my GPS (a garmin etrex), a map, and a compas (yes, you still need one) to find my way around in the backcountry. Bottom-line: the book works!

An excellent reference book, but also very readable and can be read from cover to cover. Provides just the right amount of information on GPS Systems - lots of detailed information, but not so much as to bore or confuse you.

I never could understand the manual and all of it's Lingo, This book (I call it The Bible for GPS user's) is the only book I have seen that explains everthing about GPS's,Datums,Coordinates and Map reading. I find myself reading the book every chance I get. This has put the interest back into my GPS after many month on a shelf. Wishing there was a book that would explain in "Real People"terms. Well this is the book !