Map, Compass & GPS

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

Monday, July 30, 2012

Magnetic Declination

Understanding Magnetic Declination

Declination: A Noun. The horizontal angle between the true geographic North Pole and the magnetic North Pole, as figured from a specific point on the Earth.”

 Declination is a term that causes “brain cramps” for many of my students in my map and compass classes. When I mention Magnetic Declination eyes roll.

The web site has an excellent discussion of what declination is and what causes it:

“Magnetic declination varies both from place to place, and with the passage of time. As a traveler cruises the east coast of the United States, for example, the declination varies from 20 degrees west (in Maine) to zero (in Florida), to 10 degrees east (in Texas), meaning a compass adjusted at the beginning of the journey would have a true north error of over 30 degrees if not adjusted for the changing declination. The magnetic declination in a given area will change slowly over time, possibly as much as 2-25 degrees every hundred years or so, depending upon how far from the magnetic poles it is. Complex fluid motion in the outer core of the Earth (the molten metallic region that lies from 2800 to 5000 km below the Earth's surface) causes the magnetic field to change slowly with time.

To read the rest of the post go here.

Magellan GPS

Seattlebackpackersmagazine has a good post on the Magellan Explorest GPS.

First the basics. It has a color touch screen at 3” diagonally. It operates with Lithium AA batteries which they claim will last 16 hours of continuous operation. It has a still camera and a video camera, a microphone and a speaker. It has 500 Mb of user storage and a microSD slot for additional storage. For more information see the Tech Data section at the end of this review.

To read the rest of the post go here.

Wednesday, July 25, 2012

Summer Backpacking

Do you carry the right gear when backpacking?  The web site has a great post about what should go in your pack and on your back.

I often get asked by novice and veteran backpackers “What do you pack when you do an overnight?”
Well, as luck would have it, I just got back from a 4 day backpacking trip and am unpacking at this moment. So I’ll share all of my creature comforts with you. No more and no less.

To read the rest of the post go here.

What would you add or subtract?

Sunday, July 22, 2012

Buying a GPS

Looking for the best price on a GPS, here is a site to keep your eye on.

GPS Deals finds the best sales on navigation devices from around the Web, and brings them all together here for you. Working with our broad network of partners, including Amazon, GPS Now, TigerGPS, REI, and more, we’ll keep you current on all the best GPS bargains.

GPS Deals will be updated year round, but it will be especially active and helpful around the holiday shopping season. This is the best place on the Web to find those Black Friday GPS specials. To be sure that you don’t miss a deal, subscribe to our RSS feed today. In case you’re new to RSS feeds, be sure to check out our guide to RSS.

To visit the site go here.

Tuesday, July 17, 2012

Monday, July 16, 2012

iPhone 4

On another blog, I came across this very helpful post about setting up the iPhone 4 cellphone.

The post is aptly titled "How To Use the iPhone 4 as a GPS Mapping Device for Backpacking."

Go here to read the post.

Thursday, July 12, 2012

Hiker's and Hunter's Trip Plan

Do you leave enough information with friends and family when heading into the back country?  All too often SAR teams begin a search with scarce or inadequate information.

When a hiker or hunter goes missing and 911 is called, it is not uncommon for a Search and Rescue (SAR) team to put 30 people in the field looking for the lost subject.  Generally, the reporting person can only provide generalities such as “they went to the Devil’s Lake Trail Head” or “Uncle Bob is hunting off the 5 Road in the Ochocos.”  That kind of information is not enough to plan a search.

With summer in full swing and the hunting season right around the corner it’s time to take a look at our pre-trip planning.  This is the time to prepare a trip plan.  A plan that is similar in concept to the plan that a pilot files.  It is essential to give the SAR team the information needed to plan a search to accomplish the rescue.

The first step is to identify someone who will call for help when needed.  This can be a family member or friend whom you know can be decisive and make a judgment call.  If you tell this responsible person that if you aren’t home by 9:00 to call 911 for SAR support, you know that at 9:01 that person is on the phone making a very difficult call.  

Secondly, help that responsible person and the SAR team by giving them something to go by; this is your trip plan.  On my web site I provide what I call the Hiker’s Trip Plan;  This plan gives the searchers the basic but critical information needed to plan a search and assign resources (e.g., the horse team, ATV’s, air assets, etc.).  For example, the plan asks the hiker to identify the who, what, where and when of the trip.  The details are critical.  Location information (Latitude & Longitude, UTM grid) gives them a starting point.  Let them know if someone in the party has a medical condition.  Consider attaching a marked up copy of the map you’ll be using in the backcountry.  Identify where your car is parked, the camp site and intended route.  The plan expands on all of these items.

Make this process a key part of your trip planning.   

Tuesday, July 10, 2012

Snake Bite

Every year thousands of Americans are the victim of a snake bite.  What do you do to survive a venomous bite?  The following post is from REI's site and written by a member of NOL's Wilderness Medicine Institute.

Each year in America some 6,000 to 8,000 people report venomous snakebite injuries, most by rattlesnakes. Amazing myths persist about what one should do in such an emergency, everything from sucking out the venom (which doesn't work) to electrocuting the bite victim (which hurts and just might kill you).

Rattlesnake strikingWe at the
Wilderness Medicine Institute of NOLS have been teaching people how to handle medical emergencies for over 20 years. While we love a good, improvised traction splint as much as the next person, when it comes to rattlesnake envenomation, we know that there's really very little we can offer a patient besides a speedy evacuation. The truth is that when it comes to rattlesnake envenomation injuries, the only thing that really matters is how quickly the patient gets to the hospital and receives proper antivenom therapy.
To read the rest of this fine post go here.

Thursday, July 5, 2012

Cotton Kills

Have you heard the phrase that cotton kills.  What is this all about.  Section hiker has an article that gets right to the heart of the issue.

Why does Cotton Kill?

Have you ever wondered why people say Cotton Kills? Do you understand exactly why? Here’s an in-depth explanation as well as a list of other fabrics that you should avoid when shopping for hiking clothes.  To read the rest of the post go here.

Day Pack Review

Here is a nice review of the REI Flash Day Pack.

Sunday, July 1, 2012

Book Review - Longitude

Commonly book reviews focus on the most current publications available on the commercial market.

Still, there aren’t a lot new books for the navigator.
This review is about a book first published in 1995.  The book is Longitude, The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time.  (This is probably the most accurate title of any saga that I have ever read.) Longitude was written by Dava Sobel.  It is available at  either in paperback or as a Kindle edition.

The book is set in England in the 1700’s.  The cast of characters range from Sir Issac Newton to Captain Cook yet focuses on a relatively unknown craftsman, John Harrison.
The measurement of longitude is a critical component of celestial navigation.  It’s grid partner is Latitude.  Prior to the late 1700’s the measurement of latitude had been accomplished for hundreds of years but that was only 50% of the puzzle.   With measurement of latitude, navigators we able to determine an east/west line (like the equator) but nothing to cross that line with a meridian moving north south.  Without that north south component, a ship’s position could not be accurately determined.  For many years Astronomers looked to the movement of celestial bodies to determine the elusive measurement of longitude.  The measurement of longitude through the use of an accurate time piece was discounted. 

Harrison's chronometer
Longitude is the intriguing story John Harrison’s life to design and build an accurate chronometer that could be used by mariners at sea.  The biography is about Harrison progression that began in carpentry and graduated to clock maker and eventually chronometer builder.
Initially, Harrison built case clocks (similar to a grandfather clock.)  In the 1700’s clock mechanisms were built primarily of wood.  Harrison’s talent was to use a variety of woods for gearing and structures with limited use of metals.  He refined his work such that his clocks required no lubrication.  One of his greatest achievements was a large case clock that he built in 1725 that erred by one second in a month.  Prior to this clock, quality clocks were off by one minute each day.  Consider that his work was done by hand without the aid of modern finishing equipment, this was quite remarkable.
Sobel’s book concisely outlines the development of the first four Harrison chronometers and the trials of bureaucracy and envy that Harrison endures for over 50 years.

It wasn’t until trials at sea in the late 1700s that the merit of Harrison’s chronometers became valued.  The naval explorer Captain Cook was an ardent supporter of Harrisons work and achievement. 
This book is a wonderful account of a dedicated craftsman who had a major impact on celestial navigation. 

Update:  In 2000 a film version of Longitude was produced.  It stars Michael Gambon (who played the fatherly wizard Dumbledore in the “Harry Potter” series) and Jeremy Irons.  It’s available on Netflix.