" />

Home

head for the barn

About BCL

llama packing specifically,
the great outdoors in general

Subscribe

track down our print issues

The BCL Blog

regular updates
from the trail and beyond

The BCL Archive

explore our back issues

Contact BCL

get in touch

Selecting a GPS Receiver

by Phil Romig Jr.

Introduction
On the trail, a GPS receiver can help you enjoy a trip more by making you more confident about where you are and where you are going. After the trip is over, it can provide you with a detailed map and locations for your photographs. Some GPS models can enable your family and friends to keep track of your progress, and in some situations, GPS can be a life saver. When not on the trail, the same GPS receiver can enable you to find your way around a strange city, participate in a geocaching exercise, or find your property line.

However, all of that will happen only if you:

  1. Have a GPS receiver with the necessary capabilities
  2. Know how to turn it on and take a reading
  3. Learn to use its advanced capabilities
  4. Understand its limitations and how to minimize them

We’ll assume you are starting from scratch and lead you through the steps. If you have some experience with GPS you can jump ahead to sections that interest you. However if you are a beginner, we encourage to follow the steps in the order given.

Where do you look? | What do you look for?
What factors should you consider? | Which factors are important? | Other sources:

Where do you look?
The best place for a beginner to start is a web search. For example, when I entered “comparison of hand-held gps units” into a Google search box, the first several results included:

Half an hour spend reading through these four web sites will help you feel like you know what features you might want and what types of units you should consider.

Most of the hand-held GPS receivers for use on the trail are made by a few manufacturers:

A smaller number of specialized units also are made by

Their web sites provide complete catalogs of all of the receivers they sell, along with specifications and comparisons.

The large, national chains that sell outdoor equipment (REI, Cabelas, Bass Pro, Eastern Mountain Sports, etc.) carry models from several manufacturers. If you have one near you, it gives you a chance to hold, use and compare different receivers. If not, their web sites are a great source of information for comparing different manufacturers.

Local, independent outdoor supply stores also are a great resource, especially if they know you and have a salesman that can work with you and give advice.

Finally, today a growing number of people check online retailers such as amazon.com, where they can find both information and reviews by users.

What do you look for?
Hand-held receivers suitable for the back country range from less than $100 to more than $600. All of them will determine your location; most of the price difference is based on additional capabilities. These can be software (maps, satellite photos) or hardware (compass, altimeter, camera).

Start by deciding how you want to use it:

After you have decided how you want to use it, make a list of the capabilities that you will need. For example, if you just want a small, portable system that will give you the geographic coordinates of your current location and save them in memory, you don’t need most of the other capabilities, and a basic, inexpensive receiver will do the job.

On the other hand, you also might want a unit that will store waypoints and tracks, display them on maps, and guide you to waypoints and along routes. You probably will need a removable storage medium (micro-SD card) and the ability to connect the receiver to a computer for uploading maps and routes and downloading tracks. That will require a receiver somewhere in the middle of the price range.

Other capabilities in high-end receivers include road maps, turn-by-turn directions, cameras, and many more. The point is that you need to determine your needs before you start to choose a receiver.

What factors should you consider?
Here is a list of factors that may influence your choice of a receiver:

Which factors are important?
Regardless of whether you want a basic system or a high-end system, the top priority should be a receiver’s ability to provide accurate locations almost all of the time. We will talk more about accuracy in a future article, but here are three factors to consider when selecting a system.

In principle, a receiver can calculate a location with signals from three satellites, however errors on the order of 100 feet can be introduced by atmospheric conditions. Modern receivers reduce that error by receiving signals from many satellites (channels) and using them simultaneously (parallel computation) to find the location that best fits all of the signals. I would not buy any receiver with less than 8 channels and would prefer 12.

In order to calculate locations based on multiple satellites, the GPS unit must receiver clear signals from all of them. A number of factors can weaken a signal - a cliff or large building between the satellite and the receiver, a thick tree canopy, or even your body. The more “sensitive” the receiver, the better it can receiver and decode weak signals.

To make GPS locations even more accurate, the government has established a “Wide Area Augmentation System.” Briefly, precisely located permanent stations use GPS to calculate a location and compare it with their known location. The difference (error in the GPS location) is transmitted to satellites which relay it to you hand-held GPS. If your GPS is “WAAS Enabled,” it uses that signal to reduce the error in you location. I would be reluctant to buy a GPS receiver that was not WAAS Enabled.

With one exception, most of the other factors are a matter of personal preference. The exception is the type of batteries. In remote areas, you want to be able to carry spare batteries, so that usually means AA or AAA alkaline batteries. Having low power drain (long battery life) is desirable but I would not buy a back-country receiver that does not have replaceable batteries.

After you decide which factors are most important to you, you may want to create a table with factors across the top and GPS units down the side to help you narrow down your choice and ultimately pick the receiver you want to buy.

Other sources:
A good book to help someone get started in GPS for the trail is: “Winderness GPS - a Step-by-Step Guide” by Bob Burns and Mike Burns, Mountaineers Books, 2013
Chapter 2 includes a set of charts that compare 38 GPS models that were available at the time of publication.

We will add more books to this list as we become aware of them.


Back to main Navigating the Backcountry page