What is UTM?

Hikers and backpackers frequently rely on the Universal Transverse Mercator (UTM) coordinate system for navigation. UTM is similar to latitude and longitude, but differs in a few important ways:

  • UTM is measured in meters, whereas latitude longitude uses degrees, minutes, and seconds. UTM drastically simplifies calculations, etc. when out in the field.
  • UTM uses Easting and Northing coordinates to indicate latitude and longitude.
  • UTM uses zones, e.g., 11S, along with your Easting and Northing coordinates. The zone indicates the general region you are on earth to ensure the UTM coordinates are precise.
  • Most importantly, UTM is universal for hiking and backpacking purposes. Most outdoor maps favor UTM grid lines over traditional latitude/longitude.

For those of us who practice compass navigation (as backup for electronic GPS devices and apps) it is common to identify your UTM coordinates using triangulation, slope angle navigation, etc., which are then recorded in a logbook. Should your GPS fail, you may find yourself in a situation where your map and compass skills become a survival necessity. If you’re a serious backcountry, off-trail traveler, you should be practicing your map and compass navigation as often as possible.

Aligning your map with true north, accounting for magnetic declination, is one of the first and most important skills to learn

Converting UTM Coordinates to KML

Using the UTM coordinates you recorded, it’s great to be able to visualize things in Google Earth or even load them into a GPS app for later use. On a recent off-trail backpacking trip, we relied on UTM coordinates from map and compass triangulation to find our way to some hidden Native American ruins. Google Earth and CalTopo were used to plan the trip beforehand. Afterward, we used our recorded UTM data to visualize and review our route.

Visualizing a hike or backpacking trip in Google Earth can help you identify landmarks and trail routes to avoid getting hopelessly lost

To accomplish this, I built a general purpose spreadsheet that converts UTM coordinates into both latitude and longitude and finally KML output for Google Earth or a GPS unit. Here’s how it works:

  1. Each tab is labeled and are used sequentially. Start with the first tab, “1. Summary” to enter in basic information including what you’d like to name your collection of coordinates.
  2. Use the second tab, “2. Bulk Coordinates” to enter in your coordinates manually. You can also add an optional note for each.
  3. Cut and paste the entire contents of the third tab, “3. KML Output”, to a text file using notepad and save as a “.kml” file, e.g., “mytrip.kml”
  4. Open your shiny new KML file in Google Earth!

To begin using the spreadsheet, download the spreadsheet as an Excel document, or copy it to your Google Drive. There is one additional tab showing you how the calculations work in case you want to modify the spreadsheet. Intermediate conversion calculations are represented as hidden columns on the Bulk Coordinates tab.

Summary

Now you know how to convert your manually recorded UTM coordinates into a KML file for Google Earth. You may also want to modify the spreadsheet to customize how things are displayed in Google Earth. You can also edit the KML directly in Google Earth.

Have fun out there!

73, KN6EZE

by KN6EZE-in Hiking Tips- 0