GPS Error - Part I

Our GPS receivers are very accurate.  What should the hiker do when the information displayed just doesn't look right?

Ever have one of those "GPS days" when the darn thing is providing a bearing that looks way off the mark...."that can't be right?"

Here is the typical scenario:  As the hiker leaves camp he marks "camp" as a waypoint in the GPS.  Throughout the day the hiker maneuvers about the forest and by late afternoon it is time to return to camp.  He selects "find" and calls up the waypoint for camp.  The GPS indicates that camp is two miles out on a bearing of 330 degrees; but that doesn't look right.  The hiker compares the receiver's information with map and compass.  After a bit of analysis the hiker recognizes there is a problem.  What should he do? 

I have a few recommendations to help improve the inaccuracy that the hiker is experiencing.

First, calibrate the electronic compass.  Always calibrate the compass after installing new batteries.  (Check the owner's manual to determine if your GPS has an electronic compass.)

Second, turn off the GPS, turn it back on, select "find" and evaluate the new data to return to camp.  Check the satellite view screen to ensure that at least four satellites are being tracked.  Consider moving to an area that has an open view of the sky.

Third, if the information present still looks in error, take five to ten steps in the direction recommended to see if movement effects the data displayed.

Fourth, open the battery compartment and remove one of the batteries.  Keep the battery out for 10-20 seconds and then return it to the GPS.  Power the GPS back on and repeat the process by selecting "find" to return to camp. 

Lastly, it may be that the saved position of camp was made before a solid satellite lock was achieved.  Compare the saved coordinates for camp with the plotted position of camp.

Usually, these five steps will clear up the issue.

Remember, never leave your map and compass at home.

What Maps to Take Hiking

Seattle Backpackers Magazine recently published my recent post about what maps hikers should take into the backcountry.

"In a recent map & compass class, one of my students asked me what maps I carry into the backcountry when hiking or hunting. In this piece, you’ll get all of the info you need to learn what maps to take hiking on your next adventure."

'

Navigation While Hiking in a Group

Check out my latest post featured on sectionhiker.com.

This post is all about hiking with your friends.  I provide a list of recomendations to keep you navigation on track.

Topographic Map Symbols

Colors and symbols add the detail unique to a topographic map.  These details may not be found in gazetteers or travel guides.  Map detail includes important information about elevation, water, structures, trails, ground cover and roads; and much more.

 “The mapmaker has been forced to use symbols to represent the natural and man-made features of the earth’s surface.  These symbols resemble, as closely as possible, the actual features themselves as viewed from above.”

                                                                        U.S. Army Field Manual FM 21-28                                                                                                     Map Reading and Land Navigation, 1993

Topographic maps are rich in symbols.  Specific to a location, symbols identify features such as buildings, springs, bench marks, mines and bridges.  The United States Geologic Survey’s (USGS) guide Topographic Map Symbols is four pages long and lists dozens of symbols.  To view the USGS’s complete listing go here.

The following graphics are a sampling from Topographic Map Symbols.  The symbols below are those used for rivers, lakes and canals.  Note the different colors used.

The graphic below illustrates symbols related to buildings and other man-made features.

Note that the color of these symbols is predominantly black.

Let’s highlight a few symbols that the backcountry hiker will find helpful (the symbol will be listed to the left.)

 Bench Marks are survey monuments.  Location and elevation data is accurate.   Bench Mark will be represented by the letters BM and next to it will be printed the elevation data; see map above.  In the backcountry, Bench Marks will have a brass/bronze plate at the location to identify the mark and its position data.  Please do not tamper with a Bench Mark.

A trail is highlighted in the map above.  Trails are black dashed lines.

     Useful to the hiker are four wheel drive roads (4WD) and unimproved roads.  These are commonly called jeep roads and may be usable on foot, horseback or mountain bike.  Some of these roads may not be passable by vehicle.           

Thin, powder-blue lines represent streams.  What looks like a dashed blue line (right half) represents an intermittent stream; a flow that may disappear in dry weather.

I recommend spending some time browsing through Topographic Map Symbols and to become familiar with the symbols listed. The web site www.landnavigation.org provides a fine review of colors and symbols that are linked to photographs.

Land Navigation

Navigation Term of the Week*

Outdoor Quest Image

Heading – A direction of travel.  For example, the hiker traveled on a northerly heading to the cabin.  Heading is expressed in degrees measured from North clockwise to the direction of travel.

Outdoor Quest Graphic

* or maybe the month - we'll just see.

Hiking With Children

The following highlights an article by the Statesman Journal writer Zach Umess.  It's all about hiking with children, really small children.  

"Once upon a time, going for a hike was a simple activity.

Toss a few snacks, water and appropriate gear into a backpack, lace up your hiking boots, and you're ready to roll.

That all changes once you have children.

Between diapers, changing pad, spit-up rag, food, toys, carrier, clothes — and a few million other items you'd never even considered — it can feel as though you're outfitting a small army rather than a tiny human being.

And that's without even considering your child's mood.

Taken together, it can be difficult for parents, especially new parents, to get out on the trail.
But a group called Hike It Baby, which recently opened a branch in Salem, is encouraging new parents to get outdoors by offering a supportive atmosphere on organized weekly hikes."

Zach Umess really get's into the detail of this group.  It's worth checking out the rest of his
fine article.

Trip Planning Mistakes

Philip Werner at sectionhiker.com published this post in 2014.  My friend Peter who is planning for a PCT hike forwarded this on to me.  Lots of lessons learned in this fine article.

"When Wysteria, Sherpa, and I arrived at the trail head we found 4 foot snow drifts covering the trail. It was late March, and we’d planned to backpack north over Mt Greylock past the Massachusetts/Vermont border. We knew that there might be some lingering snow in the early spring, but we had no idea winter would still be in full force. Scratch that trip.

I’ve since learned to wait until mid-April before hiking the AT in Western Massachusetts, Vermont, and New Hampshire for lingering winter snow to melt off."

Read the rest to Peter's post to read the Trip Planning Guide.

As an aside, I really appreciated the following:

"Write up a trip plan to leave with a friend or relative in case you are overdue.

• When to contact authorities if you are overdue.
• Who to call, including phone number.
• Where you parked your car.
• What your route plan was, including escape routes if any.
• What gear you are carrying."

Check out my detailed Trip Plan.