1. PRACTICAL GPS APPLICATIONS IN FORESTRY & AGRICULTURE. MIKE CLIFFORD
PRACTICAL GPS APPLICATIONS IN FORESTRY & AGRICULTURE MIKE CLIFFORD VIRGINIA COOPERATIVE EXTENSION

2. PRACTICAL GPS APPLICATIONS IN FORESTRY & AGRICULTURE
Workshop & Field Tests
Introductions; Workshop & Field Testing Objectives
Basics of the Global Positioning System.
Features and operations of GPS receivers – Garmin eTrex series & others.
Digital topographic maps - MapTech Terrain Navigator & Garmin Mapsource.
Transfer of waypoints, tracks (area perimeter), and routes (cruise lines & plots).
Set up cruise lines on Terrain Navigator and GPS units. Test in the field.
Use GPS to calculate area in the field and compare results to
1. Traditional methods
2. Terrain Navigator's area calculation figures
3. Post-collection DGPS figures.
Discuss available sources and resources.
Evaluation and follow-up.

3. GPS and GIS DEFINITIONS
GPS is short for Global Positioning System which is
"a network of satellites that continuously transmit coded information, which makes it possible to precisely identify locations on earth by measuring distance from the satellites".
Of course, many users also refer to their hand-held GPS receivers as "my GPS" ... as in the statement "my GPS'
batteries went dead and I got lost!"
GIS is short for Geographic Information System(s). "In the strictest sense, a GIS is a computer system capable of assembling, storing, manipulating, and displaying geographically referenced information , i.e. data identified according to their locations. Practitioners also regard the total GIS as including operating personnel and the data that go into the system"
( from: ).

4. PROVIDED BY GPS RECEIVERS . . .
BASIC INFORMATION
PROVIDED BY GPS RECEIVERS . . .
YOUR CURRENT POSITION
COORDINATES (LATITUDE & LONGITUDE, UTM, MGRS, ETC.)
ELEVATION (APPROXIMATE)
DIRECTION TO SPECIFIED WAYPOINTS (“MARKERS”)
(0R BETWEEN WAYPOINTS)
DISTANCE TO SPECIFIED WAYPOINTS
YOUR SPEED OF TRAVEL
YOUR DIRECTION OF TRAVEL

5. . . . AND OFTEN MUCH MORE MAPS TIME OF DAY CROSS TRACK ERROR
ESTIMATED TIME OF ARRIVAL
ESTIMATED TIME ENROUTE
COORDINATES OF CITIES & TOWNS
AREA MEASUREMENT
ETC.

6. SOME GPS APPLICATIONS HIKING HUNTING MILITARY NATURE STUDY MARITIME
COMMERCE & GOVERNMENT
RECREATIONAL
HIKING
HUNTING
NATURE STUDY
FISHING
BOATING
BIKING
SKIING
SNOWMOBILING
GEOCACHING
GOLF !
MILITARY
MARITIME
AUTOMOTIVE
SURVEYING
AVIATION
AGRICULTURE
FORESTRY
ENVIRONMENTAL
PUBLIC SAFETY

7. HOW CAN WE UTILIZE GPS IN 4-H PROGRAMMING?
EDUCATIONAL & OPERATIONAL USES
WILDLIFE MAPPING
HIGH ADVENTURE
LEADER TRAINING
SEARCH & RESCUE
BIG TREE SEARCH
SCIENCE & TECHNOLOGY
HUNTER EDUCATION
TRIP PLANNING & SAFETY
ENVIRONMENTAL EDUCATION
FISHING & CANOEING
AND LOTS MORE !

8. The NAVSTAR System
24 Satellites orbital plates ,000 miles up 12 hour orbit
from GPS Land Navigation by Michael Ferguson

9. THE EARTH: Latitude & Longitude
from GPS Land Navigation by Michael Ferguson

10. ERROR SOURCES Multipath interference Atmospheric/Ionospheric Geometric DOP Clock Ephemeris S.A. (now turned off) and Human Error!
LINE OF SIGHT
from GPS Land Navigation by Michael Ferguson

11. Plot of position accuracy using standard Lowrance GPS receiver (stationary). Note the differences in scale
5.5 hour period immediately prior to shutoff of selective availability
8 hour period immediately after shutoff of selective availability

12. MAP DATUMS
WGS84 World Geodetic System Default datum on Garmin and most other GPS receivers. Most accurate datum, but not yet in wide use on maps.
NAD27 (NAD27CONUS) North American Older datum used on most USGS topographic maps. (We will be using this datum for the workshop)
NAD83 North American Datum Very similar to WGS84. Used on newer USGS maps.
and hundreds of others!

13. COORDINATE SYSTEMS
LATITUDE / LONGITUDE (ANGULAR) DEGREES - MINUTES - SECONDS
UTM / UPS (RECTANGULAR, METRIC) UNIVERSAL TRANSVERSE MERCATOR (WE WILL BE USING UTM IN OUR FIELD EXERCISES) UNIVERSAL POLAR STEREOGRAPHIC
MGRS (UTM USING ALPHANUMERIC I.D.) MILITARY GRID REFERENCE SYSTEM
OTHERS …
TOWNSHIP & RANGE, STATE PLANE COORDINATE, ETC.

14. STANDARD CIVILIAN RECEIVERS (Selective Availability OFF)
ACCURACY
STANDARD CIVILIAN RECEIVERS (Selective Availability OFF)
HORIZONTAL ACCURACY TO 15 METERS (49.2’) OR BETTER
VERTICAL ACCURACY (altitude) TO 100 METERS (328’)

15. SYSTEMS TO IMPROVE POSITION ACCURACY
DIFFERENTIAL GPS (DGPS)
SYSTEMS TO IMPROVE POSITION ACCURACY
Coast Guard
Commercial Ground & Satellite Based Correction
Wide Area Augmentation System (WAAS)

16. WIDE AREA AUGMENTATION SYSTEM
FAA SPONSORED GEO-STATIONARY SATELLITES (# 35 for us) FREE ACCESS ACCURACY TO 3 METERS INSTALLED ON MOST NEW (2001+) GPS MODELS

18. NAVIGATION BASICS 1. KNOW YOUR POSITION 2. PLAN YOUR ROUTE
3. STAY ON YOUR ROUTE
4. RECOGNIZE YOUR DESTINATION

19. Garmin eTrex Models with Area Measurement Capability “eTrex+”
Venture $149.00
Legend $209.00
Vista $285.00

32. ENTERING COORDINATES TO CREATE A NEW WAYPOINT IN ETREX +
ON MENU PAGE, SELECT MARK.
NAME IT & SELECT SYMBOL (optional)
ENTER ELEVATION (optional)
ENTER COORDINATE DATA
SELECT “OK” AND YOU’RE DONE

33. PROJECTING COORDINATES TO CREATE A NEW WAYPOINT IN ETREX+
CREATE A NEW WAYPOINT BY ENTERING A BEARING AND DISTANCE FROM YOUR CURRENT POSITION OR ANY EXISTING WAYPOINT
ON MENU PAGE SELECT FIND.
SELECT AN EXISTING WAYPOINT AND ENTER
FROM MENU OPTION, SELECT PROJECT.
NAME IT & SELECT SYMBOL (optional)
ENTER DISTANCE
ENTER BEARING
SELECT OK AND YOU’RE DONE

34. ETREX+ AREA MEASUREMENT: Venture Legend Vista
Legend & Vista only
All 3 models
All 3 models

35. AREA MEASUREMENT TECHNIQUES
Using Venture/Legend/Vista GPS Receiver alone: *Calculate from perimeter measurement *Accessories - “area calculation” function *Route - “route area’ function (not Venture).
Using Terrain Navigator (TN) alone: *Distance Tools - trace & calculate. *Track Tool - trace, finish, calculate. *Route Tool - trace, edit/loop, calculate.
Using combination of GPS and Terrain Navigator: *Transfer GPS track to TN for calculation. *Transfer GPS route to TN for calculation. *Transfer GPS corner waypoints to TN. *Transfer TN waypts, track, or route to GPS.

36. AREA MEASUREMENT USING “ACCESSORIES”
1. On Menu page, enter Accessories
2. Enter Area Calc. (area calculation triangle).
3. Highlight and press Start (stop will appear).
4. Travel perimeter of the tract, then press Stop.
5. Record and save (as a track) if desired.
6. Clear the track log.
Area and perimeter measurements can be displayed in in a variety of units.

37. AREA MEASUREMENT USING “ROUTE” (Legend & Vista only)
1. On Main Menu page, enter Route.
2. Enter New (unless using an existing route).
3. Enter a sequence of waypoints (first and last should be the same).
4. Name and save the route.
5. Highlight route and select Route Area on the options menu.
Area measurement can be displayed in a variety of units.
Perimeter and leg distances can be viewed as selectable fields

38. SETTING UP GPS CRUISE LINES & PLOTS OR OTHER LINEAR SAMPLING
IN THE FIELD WITH GPS RECEIVER: Mark starting waypoint Project (enter bearing & distance) additional plot points Create route (cruise line & plots) (This is one of several possible methods)
USING TERRAIN NAVIGATOR: Mark starting waypoint; determine bearing & distances Use Route tool to draw cruise lines and plots Transfer to GPS receiver (This also is one of several possible methods)

39. TOPOGRAPHIC MAPS

40. AERIAL PHOTO
TOPOGRAPHIC MAP

41. TOPO MAP MARGIN INFO: BOTTOM CENTER

42. TOPO MAP MARGIN INFO: BOTTOM LEFT

43. TOPO MAP MARGIN INFO: BOTTOM RIGHT

46. MapTech TERRAIN NAVIGATOR
DEMONSTRATIONS:
MapTech TERRAIN NAVIGATOR
and
Garmin MAPSOURCE

47. THE END