Map, Compass & GPS

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

Tuesday, August 23, 2016

Finding Direction Without a Compass

Preparation and carrying the ten essentials is vital to any outdoor trip.  Map, compass and GPS make up my navigation kit.  Still, the unplanned happens and the magnetic compass may be broken or left at home.  Knowing a few common practices can make a difference.
How can you determine direction without a compass or when the compass is broken?

There are a few viable techniques that can be used to determine direction.  But first, let’s eliminate two methods that are not practical.

Let’s eliminate the old axiom of moss growing on the north side of a tree.  It is just not reliable.

Secondly, dismiss the concept that deciduous trees (e.g., oaks, maples) develop significantly more vegetative structure on a southern exposure.  Generally, one would expect more branch development and canopy on the southern side because of the amount of sunlight received.  This is getting a lot of attention on the internet.  In the Pacific Northwest the Forestry professors that I have discussed this with tell me not to depend on such an observation.

The following are a few methods that are worth remembering.

Perhaps the most accurate method to determine direction is to use the North Star (Polaris). For the backcountry hiker consider that Polaris is fixed in position over the northern pole.  Unique from other celestial stars and planets, Polaris is very closely aligned to the earth’s axis.  Stars and planets rotate around Polaris.  And like the sun, rotation is from east to west through the sky.  Polaris will be found approximately half way between the northern horizon and straight overhead.  In the northern hemisphere, Polaris can found in our northern sky and is never more 1° from true north – the North Pole.  A clear sky without a lot background glow from the light from a city is essential.  Polaris is not the brightest star in the sky. Using the North Star when it is high above the horizon is a challenge.  

Most of our compass navigation deals with sighting objects fairly close to the horizon.  For example, when orienting the topo map to true north, the map is held between waist and chest high and then observing what lies before us.  In such a situation we scan in front and compare visible terrain features to the map.  Most of the time, the hiker is looking straight out not 45° above the horizon.  When pulling the true north bearing (from Polaris) “down from high in the sky” it takes a bit of practice and patience to align the bearing to the horizon where it can be useful.

I recommend taking your compass with you on a clear night and attempt to find Polaris. 
For more information about Polaris read my post

The Sun provides an excellent means of direction finding too.  The ideal situation is one where the sky is bright and relatively free of clouds. 

The first method is called a “shadow stick compass.” In an open area, clear away forest debris and duff.  Place a stick or trekking pole (extended about three feet – longer is better than shorter) into the ground as deep as possible (see image below.)

Notice the shadow moving out from the trekking pole.  At the furthest point of the shadow, place a marker such as a rock, stick or tent peg in the ground.

Twenty or thirty minutes later, place another marker at the end of the moving shadow. 

The markers shown above were placed over a period of one hour, each thirty minutes apart.  A piece of baling twine (yellow) was laid adjacent to the markers to provide reference.  The line of markers runs east west.

To find north, I simply put the toes of my boots next to the markers with my body perpendicular to the yellow line made by the twine.  Facing away from the trekking pole, north is straight in front of me. 

A traditional analog watch (one with an hour and minute hands) can be used to locate north.  Again, a bright sunny day is ideal.

The following is quoted from the US Army field manual FM 21-76 (page 20.)

“An ordinary watch can be used to determine the approximate true north.  In the North Temperate Zone only, the hour hand is pointed toward the sun.  A north-south line can be found midway between the hour and 12 o’clock.  (See image below.)  This applies to standard time; on daylight saving time, the north-south line is found midway between the hour hand and 1 o’clock.  If there is any doubt as to which end of the line is north, remember that the sun is in the eastern part of the sky before noon and in the western part in the afternoon. On cloudy days place a stick in the center of the watch and hold it so that the shadow of the stick falls along the hour hand.  One-half of the distance between the shadow and 12 o’clock is north.”

Figure 1:  Image from Army FM 21-76

A topographic map balances the methods discussed above.  Once north is determined (discussed above) orient the map to north and compare terrain features on the map with the actual contours and features on the ground.  Identify topographic handrails such as rivers, trails, and dominant land features (e.g., mountains tops.)  These features will help guide the hiker’s travel during the day.

Such study of a map and its features builds a mental map of the area.  A mental map and terrain association is great step to determine and maintain direction.
Using Polaris and the “stick compass” can, with practice, provide good direction information.  In my opinion, using a watch to determine direction provides a trend of direction at best.  Trend of direction would be where the hiker is heading in a generally northerly direction rather than a specific bearing.
There are a few more techniques available but these three are easily remembered and don’t require more gear.  It is a fine place to start.

For more information consider:

1.    US Army Field Manual – FM 21-76
2.    Staying Found by June Fleming
3.    The Natural Navigator  by Tristan Gooley

Sunday, August 14, 2016

Surviving a Black-Out

Surviving a Black-Out is submitted by guest contributor Lee.  I don't scan the survival sites often but I think Lee's post offers some great common sense.
 Though it is easy to go through life without planning to experience a Black-Out, chances are you will endure a black-out in your lifetime. Depending on where you live, black-outs might be a seasonal occurrence. Black-outs happen for a variety of reasons. However, when a blackout happens, you'll lose power and the ability to operate as normal. When the power goes out, this shuts down access to fresh food, the ability to cook, see, use electronics and much more. Experiencing this type of inconvenience can be debilitating if it lasts for a long time. However, the crisis doesn't need to be unbearable if you prepare an emergency survival/preparedness kit. If you're experiencing a blackout, there are a few resources you need to keep in your possession.

 Sources of Light 

Even though the sun is the main source of light for the Earth, inside of buildings, people rely on electricity to power on the lights. In those eco-friendly cases, people use solar energy. However, it is important to have alternatives during a blackout. Flashlights are excellent to keep stored along with lots of batteries. Compared to flashlights, certain brands of candles are cheaper light sources as well. They're not as easy to manipulate and maneuver as flashlights. Just make sure to keep a bunch of matches on hand to light the candles. If your home has a fireplace and a chimney, these are good resources to use during a blackout to circulate heat. 

Sources of Nourishment 

In order to survive, the body needs to stay nourished. The best way to do this is through food and water. Some emergency preparedness guides offer great advice regarding how much water to store. Keep one gallon per person for each day of a blackout. This should be enough water for a person to stay hydrated and stay clean. In terms of food, it is possible to eat and get nourished during a blackout. Make sure to keep lots of canned food on hand. Keep an eye out for the expiration date of the canned foods as well. Be sure to discard any expired foods. Canned foods like fruit, vegetables, beans and meats can work well. Don't forget to keep a manual can opener stocked. To heat foods, use aluminum trays with sternos and keep foods warm for hours. There are plenty of items that will stay good on the shelf such as powdered milk and dry cereals. Dried beans and lentils are easy to soak for a period of time and then enjoy. Storing dehydrated foods is a fairly easy and convenient process. Dehydrated foods are easier to keep safe from insect contamination than dried foods. You can dehydrate foods like mushrooms and fruit. Keep them stored in sterile, glass jars. Put the lids on tight and you've got an array of food to enjoy during a blackout.

Other Helpful Resources 

Even though the electricity might be out, there are still ways to remain connected to the outside world. Keep a battery-operated radio on hand to connect to a radio signal with emergency information, local updates and weather forecasts.

A blackout has the potential to last overnight or for a couple of days. If you find yourself in this predicament, make sure to store a few pillows and sleeping bags in plastic or garbage bags. They're more likely to stay dry this way. If possible, pack an air mattress that doesn't rely on electricity for inflation. These resources will make will make the overnight experience a lot more comfortable.

With decreased lighting, the chances increase for someone to accidentally trip or miss their step somewhere. If so, make sure to have a first-aid kit on hand. Injuries notoriously happen in emergency situations. Keeping the proper medical supplies on hand will ease the angst involving an injury

Overall, emergency situations like blackouts are scary. Though they're never ideal, it is ideal to make the most of the situation by staying prepared. As you go to the grocery store for weekly groceries, purchase an extra few cans of food or a gallon of water. Before long, your entire emergency preparedness kit will be complete.

Thursday, August 4, 2016

Changing GPS Coordinates

Coordinates are the numerical values used to identify a hiker’s location in the field or on a map.  The most common are Latitude and longitude.

From the factory, GPS receivers are set are set to the format of: \

      o  Degrees         Minutes. Minutes  (example: 150° 36.30’)

There are many other formats that GPS receivers can be adjusted to.

The two most important GPS Coordinate formats in the USA are:

      o  Degrees         Minutes          Seconds
            This is common on US Geologic Survey topographic and commercial maps. (Example: 150° 36’ 30”)

Universal Transverse Mercator (UTM)
            A metric based grid system that is simple to use. Visit  UTM Grid for the hiker for more information.

Who cares?

Let’s use the example of a backcountry hiker using a hiking guide book that has a short chapter on a route plan to “Spectacular Lake.”  The guide books map representation is a little crude but has UTM GPS Coordinates for the trail head, parking lot and final destination.

To take advantage of those UTM GPS Coordinates the hiker must >power the receiver>go to the setup option (below):

From setup scroll/rocker down to and select position format.  

Note that it is selected to UTM UPS.  That is what the hiker is looking for.

Select the position format icon and explore all the GPS Coordinate formats that are available (there are quite a few.)