1. Angle, Distance, Traverse, and Leveling Errors

2. Angle Errors Reading errors – repetition and direction
Pointing errors – lining up the crosshairs
Combined reading and pointing errors
Target centering errors
Instrument centering errors
Leveling error (alignment of vertical axis)

3. Reading and Pointing Reading - repetition Reading - direction Pointing
Reading and pointing – total station (DIN)

4. Target Centering For two targets at D1 and D2 distance away:
NOTE – RESULT IS IN RADIANS!

5. Instrument Centering
Given a backsight distance D1, a foresight distance D2, and a distance D3 between targets:
NOTE – RESULT IS ALSO IN RADIANS!
For leveling error, see textbook pp

6. Combined Angular Errors
Note: Some values are in arc-seconds and some in radians. They must be converted to a consistent unit. Also, leveling error is not considered.

7. Interior Angles of a Polygon
Error propagation is error of a sum. With all interior angles measured once, there is one (1) degree of freedom. If angles are measured multiple times, they are correlated (in practical cases). Use t statistic for testing closure.

8. EDM Errors
Given instrument specifications where a is the constant portion, and b is the parts per million value …

9. Error Propagation in a Traverse
Error propagation for any type of horizontal network (including traverse) can be conveniently and properly determined through a full least squares analysis. Therefore, we will not cover traverse as a special case.

10. Fuzzy Traverse

11. Errors in Differential Leveling
Systematic
Collimation
Earth curvature and refraction
Both can be avoided by balancing BS & FS
Random
Reading (usually given in ft/ft or mm/m)
Instrument leveling
Rod leveling
In practical cases, random error is relative, based on distance or number of setups

12. Trigonometric Leveling

14. Propagation of Random Error

15. Estimated Error in a Measured Zenith Angle

16. Zenith Angle Error With Total Station