Map, Compass & GPS

Map, Compass & GPS
Wild flowers along Fall Creek on the way to the Green Lakes - Oregon

Wednesday, June 24, 2015

Navigation Term of The Month - Azimuth

An azimuth is the angular direction to an object.  Azimuths are described commonly in degree increments from either true, magnetic or grid north.

In the world of recreational navigation, GPS receiver operations and orienteering the use of the term “bearing” has become synonymous with azimuth.

Azimuth direction is measured from north clockwise in 360° increments. The point from which the azimuth originates is from the center of an imaginary circle.  This imaginary point is the operator.

Tuesday, June 23, 2015

Sleeping Bag Suggestions

 I found these suggestions on the Appalachian Mountain Club's  blog Equipped.  Their post gives provides some good common sense suggestions about sleeping bag use and care.

  1. Unstuff your sleeping bag well before bedtime, letting it fully regain its loft and warmth.
  2. If it’s chilly out, place a chemical heat warmer or hot water bottle in your sleeping bag about an hour before bedtime to kickstart warmth.
  3. Eating a dinner high in fat on cold nights generates longer-lasting heat than a carb-heavy meal.
  4. Wearing a liner balaclava while you sleep provides head and neck coverage. Bonus: It doesn’t shift around or fall off when you toss and turn.
  5. Don’t breathe into your hood. The moisture will collect in the insulation and slowly compromise warmth, especially in down sleeping bags.
  6. In the morning, stuff your sleeping bag tail-first to prevent the footbox from ballooning. Turn the bag inside out if it has a wind-resistant shell.
  7. Invest in a compression stuff sack. This will reduce the size of your stuffed bag by a third or more.
  8. At home, never store your sleeping bag compressed in its stuff sack.  Doing so will permanently crush the insulation and reduce the bag’s warmth.

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Saturday, June 20, 2015

The Ten Essentials

Always Carry The Right Gear

On a warm afternoon in July, a family leaves a trail head with the goal of summiting the South Sister Mountain in Central Oregon.  It was a rough hike as they took a path not frequently traveled.  By evening it became obvious that this group would not make it to the summit and the glacier they were attempting to cross was icing up; it just wasn’t safe to press on.  911 was called and a local SAR team reached them after midnight.  The temperature on the glacier dropped below 40° (F) and the hikers were getting cold.

When the SAR team reached them, they found that the group had some food and water but no other gear.  The hikers’ clothing selection was questionable too.

So what is the right stuff to carry in the outdoors?  What is the minimum?  What should you consider before hitting the trail?

A climbing group in the 1930s, The Mountaineers from Seattle authored the “Ten Essentials” describing ten items that should be carried in the back country. 

“The Ten Essentials” has been modified by different groups over the years.  The following is the list that REI recommends:

  1. Navigation
  2. Sun protection
  3. Insulation (extra clothing)
  4. Illumination
  5. First-aid supplies
  6. Fire
  7. Repair kit and tools
  8. Nutrition (extra food)
  9. Hydration (extra water)
  10. Emergency shelter
    1. A space blanket is fine to carry but it is a poor shelter.

This is the minimum that one should carry; it is a starting point.  The key is to always carry your kit with you.  I have a day hiking kit that fits into a fanny pack.  It is only limited by its poor ability to carry extra clothing.

Quality gear is a must.  Remember, it has to work for you when the conditions are bad.

Friday, June 19, 2015

Refresh Your GPS Skills

GPS will get you back to the truck or help you return to your favorite spot.   Confident use of the receiver comes with practice and frequent use.

Here are some simple recommendations to try in the field.

  • Dump those old AA batteries, put in new ones, and replace them again in 4 months.  If you leave your GPS on all day in the field expect to change the batteries nightly.  Consider using lithium AA’s, they last longer and work better in cold temperatures.

  • Verify that you are receiving enough satellite signals.  Check this on the satellite status screen.  Four satellites are the minimum.

  • Keep you navigation simple.  It’s easier to work with a handful of waypoints rather than list of 300.   Delete the old waypoints, the ones you will never use again.  Log important waypoints (e.g., the elk wallow) on your PC or in a notebook.  Visit or for a place to store waypoints.

  • Give key waypoints names.  Enter names like “camp” and “truck.”  It’s easier and more meaningful to find “truck” in the list of waypoints than is waypoint 542; or was it 245.    

  • Verify all waypoints saved by either checking on our map page or in your waypoint file (select “go to” or “find.”)

  • When its time to return to a destination chose “GO TO” or “Find” on your keypad or menu.  Select the waypoint from the list provided.  Press the “Page” button and rotate through the many displays to the “Compass” page.  With a “GO TO” selected, a large arrow should appear on the face of the compass.  As you move towards your destination the arrow will shift causing you to adjust your course.  When you are on course the arrow points to the top center of your receiver.

  • Compliment GPS skills with a good review of map and compass fundamentals.  Learn to back up electronic position fixing with bearing triangulation.   Worst case, a broken GPS becomes a paper weight for your map while afield.

I suggest checking out Lawrence Letham’s book GPS Made Easy from the library.  This book compliments the owner’s manual.  An excellent reference for map and compass use is June Fleming’s Staying Found.

Taking a class can further enhance you GPS knowledge.  Classes are frequently offered through the local community college’s continuing education program or at local retailers such as REI.

Tuesday, June 2, 2015

Declination Diagram

Topographic map users are familiar with the small declination diagram at the bottom of the map. 
The diagram is located at the bottom center of the map.

Let’s zoom in to the diagram itself.
The graphic and information presented relates directly to the declination of the map area, orientation of magnetic north, orientation of grid north and true north. 
Let’s discuss what that all means.
The line on the left with the star on top is the reference to true north.  True north is the principle geographic reference on all maps.  True north is oriented to the North Pole, the top of the earth.  The left and right borders of a topographic map are aligned to true north too.  True north is the principle compass orientation that the backcountry traveler will use with compass navigation.
Care should be taken when looking at the other grid lines on a map.  For example, not all township and range lines are oriented to true north.  The red lines on the map below
represent township and range.  The red numbers refer to each of the 36 sections found in a township. (A section is a square that is one mile by one mile on each side.)  Determine if these red line are oriented to true north in advance of your trip.
The next line over is “grid.”  Grid in this case refers to Universal Transverse Mercator Grid (UTM).  UTM is a derivative of the military’s grid reference system and came about after World War Two.
Some maps come with UTM grid lines laid out in a shade of light blue.  Many topographic maps only have UTM tick marks (color blue) along the four sides of the map.  The map above has those tick marks.  Small they can be seen as numbers 6 21 and 22 at the bottom.  If one was to use a straight edge to connect the 6 21 at top and bottom the line drawn would be in relation to grid on the declination diagram.  (For more information on UTM Grid check out Lawrence Letham’s book GPS Made Easy from library.)
The last line refers to magnetic north.  This data is circled in red (below.)
The line with the partial arrow head points to magnetic north (MN.)   Without getting bogged down in the pole’s location, the key thing is to understand is that magnetic north is what a compass’ red magnetic needle point to. The numerical value of 19° refers to the declination; the angular measurement between true and magnetic north.  In this case, the declination is 19° East.  It is this value that the hiker will compensate for in navigation. 
To keep things simple, I use a declination adjusted compass so that I do not have to calculate compass values.  For example, if the hiker is using a standard compass, 19° East declination (from the West Coast) would be subtracted from a bearing/azimuth of 100° True to get the correct magnetic heading.  This gets a bit sticky and that is why an adjustable compass is so valuable.  With an adjustable compass, you adjust the compass housing once for the local declination.  Once adjusted you are set and won’t need to worry about adding or subtracting the declination value.
The declination value on older maps has probably changed from what is printed.  Declination changes over time.  As a matter of routine I visit to get the correct value before leaving home.

Monday, June 1, 2015

Night Navigation

What should you consider if you must travel at night in the wilderness?

The day started clear and bright as the hikers left the trail head near Newport, Oregon.  The temperatures were to be moderate most of the day with slight cooling in the evening.  They pressed on determined to reach the summit before twilight.  After reaching the summit at dusk, the group started to make their way back to the trail head as fog began to roll in.  Within an hour the darkness was becoming a problem and the safety of continued travel became questionable.
So what are some basic considerations for night time travel and navigation in the backcountry?
First, let us consider that we are not in a “lost hiker” scenario.  If lost, the best thing to do is to just stay where you are.  This makes the job much easier for the searchers. 
Further, recommendations are based on the concerns and issues of hiking when it is really dark, not during the period of a full moon with some ambient light.
One of the key factors in this situation is to have an understanding of the physiology of the eye. Our eyes are designed to provide optimal performance during periods of light.  The components of the eye (the retina, rods and cones) are arranged specific to their function.  The cones are the discriminators of fine detail and color.  Cones are the most effective in light, and are located near the center of the eye interior.  In complete darkness, a cones’ effectiveness is significantly reduced.  Rods are located on the periphery of our interior eye, are not fine detail discriminators and have a higher sensitivity to low light levels.  Rods are important to our night time vision.  

 To read the complete post go here.

Backcountry Navigation Recommendations

A good friend sent me an email/post on an interview of Liz Thomas.  The theme of the email/post is backcountry navigation.

Having not heard of Ms. Thomas before, I did a quick internet search that caused me to land on her Facebook page.  She is a well traveled woman.  From her face book I learned that:

"She is a well-traveled adventure athlete most known for breaking the women’s unsupported speed record on the 2,181-mile long Appalachian Trail in 2011. She has completed the Triple Crown of Hiking–the Appalachian Trail, the 2,650 mile Pacific Crest Trail, and 3,100 mile Continental Divide Trail–and has backpacked over 10,000 miles across the United States on long distance hiking trails."

 The following is from Liz Thomas:
1. Keep your mind and body sharp
It’s really hard to navigate if you’re hungry, thirsty, or cold. “An unfueled brain is more likely to make poor decisions,” Thomas says.

2. Confirm your location on your map often.
Sounds obvious, but this is the single best way to prevent wandering off course. “I hike with a map in my hand, pocket, or—a little embarrassingly— stuffed in my bra,” Thomas says.

3. Learn to read contour lines.
GPS units are great, but you still need to be able to read a map. That means understanding how contour lines represent real-word terrain. Get started: Make a fist into “Knuckle Mountains.” Draw a circle around each peak, or knuckle, keeping your pen at the same “elevation” as you draw each line. Draw concentric circles on each knuckle, connecting points that are the same height. Flatten your hand: The lines represent different “elevations” on the topographic map of your fist.

4. Learn the difference between true north and magnetic north.

A compass needle points to magnetic north. That’s not the same as true north (the North Pole, or the direction of the North Star). The difference between true north and magnetic north is called declination; it changes over time (as the Earth’s magnetic field shifts), and it varies according to your location (see below). Learn how to account for it at

5. Think like a railroad builder. 

Traveling cross-country? Observe the landscape and imagine, “If I were a railroad engineer, where would I build the line?” You will likely choose the path of least resistance.

6. Use nature’s bumper lanes.

Ridges, rivers, and prominent peaks can all serve as route boundaries. Pay attention to the terrain that borders your route, and use landmarks to avoid going astray.

7. Avoid shortcuts.

Not only does cutting switchbacks or taking shortcuts cause erosion, but it’s also an easy way to get lost.

8. Enter the right datum in your GPS.

Technology is great—if you use it correctly. The most common GPS error: failing to match datums (the systems used to match features on the ground to coordinates on the map). For example, a WGS 84 coordinate taken from Google Earth and entered into a GPS set to NAD 27 can be up to a quarter mile off.