978-0134604657 Chapter 8

8 TOTAL STATION INSTRUMENTS; ANGLE OBSERVATIONS

Asterisks indicate problems that have partial answers given in Appendix G.

8.1 Describe the proper procedure for transporting a total station instrument in the field.

From Section 8.5, paragraph 5: “When moving between setups in the field, proper care

8.2 Why should a total station never be transported on a tripod?

8.3 What are the primary sources of random instrumental error in a total station instrument.

Random instrumental errors are:

8.4 Describe under what conditions parallax can exist and how it can be detected.

(*)

8.5 Name and briefly describe the three main components of a total station.

8.6 Why are the bases of total station instruments designed to be interchanged with other

equipment?

8.7 Why is it important not to sight the EDM reflector when turning an angle?

8.8 How are the relative precisions of total station instruments differentiated?

8.9 What is meant by an angular position?

8.10 What is the purpose of the jog/shuttle mechanism on a robotic total station?

From 8.4, subsection 4: In servo-driven total stations (see Figure 8.7), the lock and tangent

8.11 How can the maladjustment of a level vial be detected on a total station?

8.12 Determine the angles subtended for the following conditions:

8.13 What is the error in an observed direction for the situations noted?

*8.14 Intervening terrain obstructs the line of sight so only the top of a 6–ft long pole can be

seen on a 250-ft sight. If the range pole is out of plumb and leaning sideways 0.025-ft per

vertical foot what maximum angular error results?

250 206264.8″/rad = 123.8″

8.15 Same as Problem 8.14, except that it is a 1.5-m pole that is out of plumb and leaning

100 206264.8″/rad = 30.9″

8.16 Discuss the advantages of a robotic total station instrument.

From Section 8.6: “The computer retrieves the direction to the point from storage or

8.17 What instrumental errors are compensated by averaging an equal number of observations

with the telescope direct and reversed?

8.18 Describe the process of placing a point on line between two existing stations when the

two stations are not intervisible.

8.19 An interior angle x and its explement y were turned to close the horizon. Each angle was

observed once direct and once reversed using the repetition method. Starting with an

initial backsight setting of 0°00’00” for each angle, the readings after the first and second

turnings of angle x were 62°38’24” and 62°38’22”, and the readings after the first and

second turnings of angle y were 297°21’38” and 297°21’40” Calculate each angle and

the horizon misclosure.

*8.20 A zenith angle is measured as

84 13 56

 



in the reversed position. What is the equivalent

zenith angle in the direct position?

8.21 What is the average zenith angle given the following direct and reversed readings.

8.22 Direct:

0 00 00 ,84 0236 ,202 22 26 ,285 14 15 ,0 00 02

         

    

8.23 Direct: 0°00′00″,98°22′58″,189°19′33″,267°42′44″,360°00′02″

*8.24 The angles at point X were observed with a total station instrument. Based on 4 readings,

the standard deviation of the angle was ±5.6″. If the same procedure is used in observing

each angle within a six-sided polygon, what is the estimated standard deviation of closure

at a 95% level of probability?

±27″;

 

1.9599 5.6 6 26.9



8.25 The line of sight of a total station is out of adjustment by 5″.

8.26 A line PQ is prolonged to point R by double centering. Two foresight points

R

and

R

are set. What angular error would be introduced in a single plunging based on the

following lengths of QR and

RR

 

respectively?

8.27 Explain why the “principal of reversion” is important in angle measurement.

*8.28 A total station with a 20″/div. level bubble is one divisions out of level on a point with an

altitude angle of 38°50′44″. What is the error in the horizontal pointing?

8.29 What is the equivalent altitude angle for a zenith angle of 86°14′38″?

8.30 What is the equivalent altitude angle for a zenith angle of 265°13′56″?

8.31 What error in horizontal angles is consistent with the following linear precisions?

8.32 Why is it important to check for sloppiness in a tribrach?

8.33 Describe the procedure to adjust a level bubble on a total station.

From Section 8.19.1: “To make the test, the instrument should first be leveled following

the procedures outlined in Section 8.5. Then after carefully centering the bubble, the

8.34 List the procedures for prolonging a line of sight.

See Section 8.15

8.35 A zenith angle was read twice direct giving values of 83°15’34″ and 83°15’30″, and twice

reverse yielding readings of 276°44’16″ and 276°44′20″. What is the mean direct-face

zenith angle? What is the indexing error?

8.36 A zenith angle was read twice direct giving values of 94°05’24″ and 94°05’28″ and twice

reverse yielding readings of 265°54′20″ and 265°54′22″. What is the mean direct-face

zenith angle? What is the indexing error?

8.37 A total station has an ISO 17123-3 specified accuracy of ±2″. What is the estimated

precision of an angle observed with 4 repetitions?

8.38 A total station has an ISO 17123-3 specified accuracy of ±5″. What is the estimated

precision of an angle observed with 2 repetitions?