South Carolina Geographic Alliance Global Positioning Systems for the Classroom

1. South Carolina Geographic AllianceGlobal Positioning Systemsfor the Classroom Mark Musselman Audubon Center at Francis Beidler Forest Harleyville, South Carolina

2. Where is the SC Geographic Alliance?

3. Capitol Southeast of the Lawmakers

4. Library and reflecting pool East of the Books

5. Horseshoe Southeast of the Old Campus

6. Russell House Close to Campus Dining

7. The SCGA is here! The Callcott Building

8. Where is the SCGA? Would any of the previous descriptions have been sufficient for a person to find the SCGA in this building? Maybe, but is there a more precise method to describe your location on the Earth’s surface? Photo credit: NASA

9. Latitude and Longitude Angles measure in degrees, minutes, and seconds of an arc.

10. Latitude and Longitude Latitude (is "fatitude" around the waist of the Earth) measured north and south of the Equator

11. Latitude and Longitude Longitude measured east and west of the Prime Meridian

12. Latitude and Longitude • Minutes (represented as ' ) and seconds (represented as '' ) of arc are different than the minutes and seconds on a clock. • 1o=60'=3600'' • In fact... • 1 hour of Earth's rotation covers 15o longitude (360o/24 hrs = 15o)

13. Latitude and Longitude • Key lines of latitude are: • Equator (0o) divides the Earth into the • Northern and Southern Hemispheres

14. Latitude and Longitude • Key lines of latitude are: • North Pole (actually, a point at 90oN)

15. Latitude and Longitude • Key lines of latitude are: • South Pole (actually, a point at (-90o or 90oS)

16. Latitude and Longitude • Key lines of latitude are: • Tropic of Cancer (23.5oN)

17. Latitude and Longitude • Key lines of latitude are: • Tropic of Capricorn (-23.5o or 23.5oS)

18. Latitude and Longitude • Key lines of longitude are: • Prime Meridian (0o): The Western and Eastern Hemispheres are measured west and east of the Prime Meridian to where they meet at the 180th Meridian • 180th Meridian: (180oE and 180oW, generally the International Date Line)

19. Latitude and Longitude The combination of a latitude coordinate and a longitude coordinate designates a unique point on the surface of the Earth. For example… True or false: xoS/yoW is not a point within the United States.

20. Latitude and Longitude • True • Even without values for x and y (xoS/yoW ), you can answer that the statement is true because no U. S. points lie within the Southern Hemisphere.

21. Global Positioning System The basis of GPS is triangulation from a selection of the 24 satellites in known Earth orbit.

22. Global Positioning System To "triangulate," a GPS receiver (GPSr) measures distance between the receiver and the satellites using the travel time of radio signals. speed x time = distance where speed is assumed to be 300,000 km/s (speed of light)

23. Global Positioning System Mathematically four satellite ranges are needed to determine exact position. Three are enough if we reject ridiculous answers (points in the center of the Earth or high in the atmosphere).

24. Global Positioning System • GPSr accuracy is diminished by: • Clock inaccuracies within satellites • Satellite location inaccuracies • Atmospheric signal interference • Signal interference caused by obstructions (trees, buildings, mountains, etc.) • Number of satellites available to the user (above the horizon) and their positions in relation to each other

25. How can I identify a GPSr? Basic GPSr Operation

26. Basic GPSr Operation Power up! Press and hold the bottom right button until the welcome page appears.

27. Basic GPSr Operation Getting started! Press the top button three times. The satellite page will appear. Scroll through the pages by continuing to push this button.

28. Basic GPSr Operation

29. Basic GPSr Operation

30. Basic GPSr Operation Satellite Page

31. You are here Basic GPSr Operation

32. Basic GPSr Operation Marking your position – waypoint Press the “mark” button and your current position (coordinates) will be shown with a default 3-digit name assigned to the waypoint.

33. Basic GPSr Operation Marking your position – waypoint A waypoint is a “point along the way.” It may be somewhere you’ve never been or a place to which you wish to return. Press OK to save the waypoint with the assigned name – in this case, it is 001.

34. Basic GPSr Operation Marking your position –waypoint To change the waypoint name, toggle down until 001 is highlighted. Press the center of the thumb stick to reveal the keyboard. Toggle across the keyboard to edit.

35. Basic GPSr Operation Entering waypoints in advance Waypoints can be downloaded directly from a computer using free software such as EasyGPS at http://www.easygps.com, which accommodates most GPS models. For example, all 280 waypoints of the Foothills Trail in SC are available at http://www.travelbygps.com/premium/foothills/foothills.php

36. Basic GPSr Operation Entering waypoints in advance With a few clicks of the mouse, all the data for the Foothills Trail can be loaded to your GPS unit!

37. Basic GPSr Operation Entering waypoints in advance Pre-trip waypoints can be displayed on topographic maps, which can be loaded to a GPS unit. A desire for the easiest route is all the motivation one needs to understand contour lines.

38. Basic GPSr Operation Entering waypoints in advance Just as the name can be changed, so too can the location (coordinates). Toggle down until the location field is highlighted. Press the center of the thumb stick to reveal a number keypad for editing.

39. Basic GPSr Operation Navigating to your waypoint If you have a waypoint already displayed, simply toggle to the Goto button and press the center of the thumb stick.

40. Basic GPSr Operation Navigating to your waypoint If you already have waypoints loaded to your unit, press the bottom button on the left side to reveal the options. Select “Waypoints”. Waypoints may be displayed by name or by the nearest to your current position.

41. Basic GPSr Operation Navigation Page

42. Basic GPSr Operation Navigation Page After selecting to “Goto” a waypoint, the compass navigation page will appear. The compass is a graphic and not magnetic, so it likely will not be pointing toward the correct direction of travel. Once you begin to move, it will orient properly with the arrow pointing toward the destination.

43. Basic GPSr Operation Navigation Page An inexpensive magnetic compass and a map are essential items in the event your GPS unit fails to operate.

44. Basic GPSr Operation Navigation Page Turn off the unit whenever practical to conserve battery life. Remember, batteries will ALWAYS fail at the most inconvenient moment. Push and hold button until screen clears.

45. Geocaching

46. What is a Cache?

47. What is a Cache? Cache - (kash) n. 1. a hiding place for treasure or provisions. 2. hidden treasure or provisions. (caching, v.) to place in a cache

48. Cache Name

49. Cache Waypoint

50. Cache Coordinates