1. Location and Direction
Chapter 07

2. Latitude and Longitude
The earth is gridded by imaginary lines called:
Longitude
Latitude

3. Building 16-105 @ Highline CC
Latitude =
Longitude =

4. GPS coordinates
Global Positioning System
Geocaching

5. Length of a degree of Longitude
The length of a degree of longitude decreases as you travel from the equator to the north or south pole.
Seattle: 1˚ ≈ 47 miles

6. Length of a degree of Latitude
Parallels are constructed approximately the same distance apart.
Seattle: Seattle: 1˚ ≈ 69 miles

8. Distances
Your text book covers finding the distance between to locations.
Remember: The earth can be approximated as a sphere.

9. Direction The angular relation of one line to another
Measured in Degrees
A complete circle is equal to 360˚

10. Degrees….not base10 360˚ = complete circle 1˚ = 60’ = 60 minutes
60’ = 60” = 60 seconds
For example: 50˚30’45”

11. Calculations
Converting from decimal degrees to degree/minutes/seconds.
Adding Angles
Subtracting Angles
borrowing

12. Surveyor’s Compass
Used to measure bearings or included angles.

13. True North (TN)
Location of the North Pole

14. Magnetic North (MN)
Magnetic North is where the compass north arrow points.

15. Magnetic Declination
The meridian indicated by the needle on a compass seldom coincides with the true meridian.

17. Bearings
Angle to the north or south meridian from the quadrant east or west.

18. Plotting a traverse
POB – Point of beginning
Error of closure