Assignment3 Surveying

Group 1

Alfiya Kulmukhanova

Bakhtiyar Rakhmetov

Rassul Bairamkulov

Sanzhar Askaruly

2014

Introduction

Surveying - is the technique, profession, and science of accurately

determining the terrestrial or three-dimensional position of points

and the distances and angles between them, commonly practiced by

licensed surveyors, and members of various building professions.

These points are usually on the surface of the Earth, and they are

often used to establish land maps and boundaries for ownership,

locations or other governmentally required or civil law purposes.

Equipment

Total station is an electronic/optical instrument used in

modern surveying and building construction. The total station is an

electronic theodolite integrated with an electronic distance meter

to read slope distances from the instrument to a particular point.

Figure 1. Total station

It consists of 3 main parts:

1) Tripod - to supports any one of a number of surveying instruments and for rough adjustment of the instrument.

2) Tribrach – used to hold the total station installation and further fine adjustment.

3) Total station - – Multifunctional electronic surveying instrument. Theodolite integrated with electronic distance meter.

Figure 2. Tripod Figure 3. Tribrach Figure 4. Total station

Another important part of total station is surveying prism.

Figure 5. Surveying prism

Surveying prisms are manufactured from high-quality optical glass

which is worked to strict specifications. All reflective surfaces

are provided with a resistant coating so that the reflectivity is

not adversely affected by dirt or condensation.

Personnel:

o Amangul Imanghaliy for the instructioning and general

guidelines

o Kunsulu Bekish and Umut Bakhbergenova, the 2 year civil

engineering students for more detailed info about

surveying.

Adjustment technique

The tripod was unfolded and placed on the flat floor between 8 and 9

blocks. Tribrach and total station were put and fixed on the top of

tripod. The station was adjusted in two steps. Firstly, the tripod

legs were adjusted in order to achieve flat position of the station.

This is done by stretching or shrinking tripod legs and is

controlled by looking at an air bubble on the top of tripod. Also

the light beam from the below of the station helped to perform this

operation. Then, the fine adjustment was made using the rotating

parts of the tribatch. The instrument helped to perform fine

adjustment of the instrument. So the necessary fine flatness was

reached.

Surveying procedure

After fine installation of the total station two team members placed

two prisms at different points it the distances over 15m from the

station. Then the distance from the station to the prisms was

measured. Also, the horizontal and vertical distances and face left/

face right angles were measured.

The key principle of prism is the reflection of the light coming

inside it. There are three reflecting surfaces inside the device;

each 2 of them make 90 degrees with each other. So the light coming

inside the prism is reflected straight to the source. During the

distance measurement, the light beam is sent from the station to the

prism and comes back. Measuring time between sending and receiving

the signal, the distance from the station to the prism is measured

by the Electronic Distance measurement device.

Total station is advanced technology and calculates all the values

automatically from the vertical angle and slope (inclined distance)

between the station and surveying prism. To calculate horizontal and

vertical distances then, slope and vertical angle measurements are

manipulated automatically in the device. To check the accuracy of

measurements, along with values required in the task slope and

vertical angle were also noted to calculate the required values

manually and to compare manual and measured results. As for vertical

angle measurement zero value is set in the vertical direction

pointing upwards, the actual angle value between slope and

horizontal distance will be (90°- vertical angle).

The level of preciseness of stations value is very high. However, it

is still affected by outside noise such as people’s movement and

touching the station. The level of values oscillation was very low

(around 3mm for distances and few degrees for angles) so our group

noted the average values given by the station.

Measured values:

Horizontal angle PAQ (face right) = 32°25’

Horizontal angle PAQ (face left) = 212°26’

Horizontal distance AP=27.946m

Horizontal distance AQ=27.340m

Relative height difference between A and P = 0.045m

Between A and Q = -

0.239m

Manual calculations:

Slope AP = 27.946m

Vertical angle = 89°54’28’’

Horizontal distance AP = Slope AP*(90°-Vertical

angle)=27.946*(90°-89°54’28’’)=27.946m

Relative height between A and P = Slope AP*(90°-89°54’28’’)

=0.045m

Slope AQ = 27.341m

Vertical angle=90°30’03’’

Horizontal distance AQ = Slope AQ*(90°-Vertical

angle)=27.341*(90°-90°30’03’’)=27.340m

Relative height between A and Q = Slope AQ*(90°-90°30’03’’) =-

0.239m

Comparing calculated and measured results for horizontal and

vertical distances, it is obvious that the level of accuracy of

total station is extremely high.

After getting distances between station and points Q and P, and

checking their values, horizontal and vertical distances between P

and Q can be calculated.

HorizontaldistancePQ=√AP2+AQ2−2AP∗AQ∗cos (PAQ)=15.443m

VerticaldistancebetweenP∧Q=¿ VerticaldistancebetweenA∧P−VerticaaldistancebetweenA∧Q=¿

¿0.045−(−0.239 )=0.284m

Conclusion

During this laboratory work our team learnt essential basics of surveying procedure and was able to gain practical experience of measuring surveying data using total station. Techniques for adjustment of station level and taking measurements were also learnt. Measurements were checked manually using geometric relations and manual calculations have shown that the values given by total station are very accurate.