Introduction to GPS and Orienteering

Transcription

1 Introduction to GPS and Orienteering There are a wide variety of GPS units available. Most GPS units are fairly similar though not exactly the same. This tutorial is specific to the Garmin emap GPS. If you have a different model, some of the instructions in this tutorial may not work for you. Setting up the GPS Turn on the GPS unit by holding the PWR button on the left hand side of the unit for a few seconds. The GPS should go through the following two screens as it warms up. When the second screen appears, press ENT. Since we are setting up the GPS indoors, we need to deactivate the GPS function in order to save battery power. To do this, press the MENU button. The first option in the menu is Use Indoors. To select this option hit ENT. This should take you back to the main screen and display a message that the GPS is turned off for indoor use. When this appears, hit ENT.

2 Next, we need to make sure that all of the GPS units are set to the same datum. Press MENU twice in order to get to the main menu. Once in the main menu, arrow down until you get to the Setup option and press ENT. This brings you to a set of tabs with different options. Arrow to the right until you get to the Advanced tab and press ENT. Make sure that your settings match those below (Location Format: hddd.ddddd ; Map Datum: WGS 84; North Reference: True; Magnetic Variation: leave blank; Direction Display: Numeric Degrees). To change a setting, arrow down to it and press ENT. A dropdown menu will appear with various options. Arrow down to the desired option and press ENT to select that option. You are almost ready to begin using the GPS. When you go outside, you will need to turn the GPS function on. You can do this the same way you turned it off. Next, navigate back to the main menu by hitting the MENU button twice. Arrow down to GPS Info and hit ENT. This will take you to a screen that displays coordinates, elevation, speed, accuracy, satellites, and satellite position. If you ever need to get back to the home screen or simply go back a screen, hit the ESC button. Getting acquainted with the GPS unit For this part of the exercise, we will be in four groups. Once you have been assigned to a group and given your locations, you may venture outside. (Locations include the MOSS parking lot, Dining Lodge, lake, and cabin 6.) Make sure that the GPS function on your GPS unit is activated for outdoor use and follow the steps below. 1.) Start at the door to the classroom. 2.) Travel toward the Location 1. What do you notice about the coordinates on the GPS?

3 3.) Go back to the door to the classroom. 4.) Travel toward the Location 2. What do you notice about the coordinates on the GPS? 5.) Go back to the door to the classroom. 6.) Travel toward the Location 3. What do you notice about the coordinates on the GPS? 7.) Go back to the door to the classroom. 8.) Travel toward Location 4. What do you notice about the coordinates on the GPS? 9.) Go back to the classroom. 10.) Discuss answers as a group. Cartesian Plane and the Lat/Long Coordinate System The Lat/Long coordinate system is much like the Cartesian plane in mathematical applications: the y axis is the Prime Meridian, the x axis is the equator, quadrant I is northeast, quadrant II is northwest, quadrant III is southwest, and quadrant IV is southeast. However, the coordinates are not listed in the same order. Instead of moving over and then up like in mathematics, GPS coordinates move up and then over. This means that the Source: N/S coordinate is always listed before the E/W coordinate. Some GPS units

4 use N, S, E, and W to indicate directionality while others use positive and negative numbers to indicate direction. If the N/S coordinate is positive, it indicates you are north of the equator. If the N/S coordinate is negative, it indicates you are south of the equator. If the E/W coordinate is positive, it indicates you are east of the Prime Meridian. If the E/W coordinate is negative, it indicates you are west of the Prime Meridian. Orienteering Sometimes depending on the weather, tree density, and other similar factors, GPS units may not be able to obtain a satellite signal. When this happens, it is good to have some orienteering skills as a backup. For this part of the exercise, we will be using magnetic compasses. Below is a diagram depicting the various parts of a compass. Source: The magnetic needle and degree dial are key parts of the compass to know. When holding the compass level, the red part of the magnetic needle will always point north unless there is a magnet nearby to interfere. If you line up the degree dial with the magnetic needle you can determine magnetic declination. Magnetic declination indicates a direction of travel in degrees. This is very useful when looking for specific locations. You can use magnetic declination in combination with distances and landmarks to create or use a map. Let s practice!

5 1.) Hold your compass level and determine which direction is north. Point in that direction. 2.) Turn your degree dial so that it lines up with the magnetic needle. At what declination is the SmartBoard? At what declination is the hand sanitizer stand? At what declination is the coat rack? At what declination is the paper towel dispenser? 3.) Choose a partner. Each pair is responsible for creating a map to an object within the classroom. Make sure to choose a clear starting point. You may use the following tools to create your map: compass, meter tape, paper, writing utensil, observational skills, and creativity. 4.) Once everyone is finished, we will switch maps. Each pair will be responsible for finding an object that another group mapped. Good luck! GPS/Orienteering Wrap Up Now that you are familiar with GPS units and orienteering, here s your chance to show off your skills. Each field group will be provided with a GPS coordinate for a hidden object on campus. In your groups, you will be responsible for finding this object and then creating a map to that same object using the principals of orienteering. Once everyone has finished their maps, we will exchange maps and attempt to find a new object using orienteering principals. Keep in mind that your directions do not have to be purely scientific. Go 10 meters at a declination of 20 is nowhere near as fun as take 10 giant steps at a declination of 20 or take 100 baby steps at a declination of 20. You may use the same tools as you did before: compass, meter tape, paper, writing utensil, observational skills, and creativity. Good luck!