Surveying Lab5 - Lexa.docx

Visayas State University College of Engineering Department of Geodetic Engineering Visca, Baybay City, 6521-A, Leyte, Philippines Vision: A globally competitive university in science, technology and environmental conservation. Mission: Development of a highly competitive human resource, cutting-edge scientific knowledge and innovative technologies for sustainable communities and environment.

ESci 121n –Fundamentals of Surveying Laboratory Exercise No. 5 INCLINED STADIA SIGHTS Name: Kenny Peter A. Yao

Date Performed: March , 2019

Course and Year: BSABE-1

Date Submitted: March , 2019

I.

Score:_____ __

INTRODUCTION In this lab exercise the class used a theodolite in determining the inclined stadia sights. So, what is a theodolite? A theodolite is a precision instrument for measuring angles in the horizontal and vertical planes. In this exercise the class used the instrument to measure the angle in vertical plane. In this exercise the class must be able to determine 3 things. The height of the instrument, the hair readings, and the angle in vertical plane using the theodolite.

II.

LEARNING OUTCOMES

At the end of the laboratory class, the students should be able to:

III.

•

Determine inclined stadia distance and its horizontal and vertical components

•

Determine the elevation of a distant point

MATERIALS AND TOOLS NEEDED

The materials and tools needed in this laboratory exercise are: - theodolite or engineer’s transit - tripod - stadia rod - field notebook

IV.

PROCEDURE

The instrument was set-up and levelled on one end of the designated line, point A. the rodman was directed to hold the levelling or stadia rod vertically at the other end of the line, point B and a foresight was taken on the rod. The apparent location of the stadia hairs on the rod was observed and the upper stadia hair reading, and lower stadia hair reading was recorded. Also, the apparent location of the horizontal cross hair on the rod was recorded as the rod reading. Next, the vertical angle was read, and its quantity was recorded. Afterwards, using the stadia rod, the actual height of the instrument above the occupied point was measured and recorded as HI. Lastly, all measured and computed values were tabulated accordingly using the sample format provided.

RESULTS AND DISCUSSION

V. HI:

1.29

ELEVATION OF POINT A:

0

Hair Reading

Sta. Occ.

Sta. Obs.

Upper

Hor.

Lower

0

63.64

1.68

1.51

1.34

K: 100 Stadia Distance

S

Vert. Angle

HD

VD

ID

0.34

13038’

32.11

7.79

33.04

The occupied point is 0 and the observed point is 63.64. The upper reading is 1.68 and the lower reading is 1.34. The horizontal/middle reading, 1.51 is obtained by getting the sum of the upper and the lower reading and divided this into 2. The stadia intercept denoted by s is 0.34 which was obtained by getting the difference between the upper and the lower hair reading. The vertical angle is 13038’ which was obtained from the vernier. The instrument height is 1.29 which was measured by using the stadia rod. The stadia distances, HD, VD and ID with measurements 32.11, 7.79 and 33.04 were obtained from computations using the vertical angle as alpha or the reference angle. Formula in determining the horizontal, vertical and inclined distances for external and internal focusing are the following:

External Focusing HD= KsCos2(α) + CCos(α) VD= KsCos(α)Sin(α) + CSin(α) ID= KsCos(α) + C

Internal Focusing 2

HD= KsCos (α) VD= KsCos(α)Sin(α) ID= KsCos(α) External and internal focusing can be distinguished depending on the specifications of the instrument used.

VI.

SKETCH

VII. CONCLUSION

VIII.

AND RECOMMENDATION(S)

REFERENCES