CONTENT PAGE

COVER PAGE 1

TABLE OF CONTENT 2

INTRODUCTION TO TRAVERSING 3-4

OBJECTIVE 5

OUTLINE OF APPARATUS 6-9

DATA FIELD 10-15

DISCUSSION 16

CONCLUSION 17

REFERENCES 18

TABLE OF CONTENT

TRAVERSING REPORT

INTRODUCTION TO TRAVERSING

Traversing

1) Traversing is that type of survey in which a number of connected survey lines form the framework and the directions and lengths of the survey lines are measured with the help of an angle measuring instrument and a tape or chain respectively.

Site Surveying Report 2 (Traversing). (n.d.). Retrieved July 1, 2015, from http://www.slideshare.net/Haziq1511/site-surveying-report-2-42339915?related=1

Types of surveying

Open Traverse- Where the line does not end in the starting point. It end in somewhere else.

Close Traverse- When the line form a route and it end in the starting point. This is known as close traverse

Example: Open Traverse and Close Traverse

Station Selection

The station must mark out clearly so it can be seen easily and measure accurately. The following are the requirement of the selection of traversing station.

- The traverse leg height and distance must be equal. - Only neighbouring stations along cross lines need be inter visible.- The stations should form a traverse of suitable shape

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AzimuthThe angular distance usually measured clockwise from the north point of the horizon to the intersection with the horizon of the vertical circle passing through a celestial body Compare altitude (sense 3)

Bearing A bearing is an angle less than 90° within a quadrant defined by the cardinal directions (Penn State College of Earth and Mineral Sciences, 2014).

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OBJECTIVE

• To enhance the students knowledge in traversing procedure.

• To identify the spot relative heights and possible errors occurred.

• To establish a new benchmark.

• To determine the difference in height of discrete points.

• To enable students to get hands-on experience in setting up and working with the theodolite.

TRAVERSING REPORT

Outline of Apparatus

Theodolite

A Theodolite is an instrument for measuring both horizontal and vertical angles, as used in triangulation networks, and geo-location work. It is a tool used in the land surveying and engineering industry, but theodolites have been adapted for other specialized purposes as well. Other specialized purposes make Theodolites ideal for shop and factory floor layout of tools and fixtures. They also work well for layout for the construction of concrete slabs, swimming pools, golf courses, landscaping, and road design.

The horizontal accuracy of Theodolites depends on "seconds". A 2-second theodolite is more accurate than a 5 or 9-second theodolite. If you think about the horizontal circle that a theodolite rotates around, the circle is divided into 360 degrees. Each degree is divided into 60 minutes, and each minute divided into 60 seconds. Think "Degrees / Minutes / Seconds". The horizontal angle is the measure of inaccuracy (hence accuracy) that a theodolite can horizontally measure or locate within. If a theodolites accuracy rating is 2 seconds (written 2") then its only going to lose 2 seconds of horizontal measurement in a given distance. Generally speaking, a 9 second theodolite is for construction sites where you're working relatively up close, say within 200 feet from the instrument. A 2 second you would work 2,000 feet away and still work with some level of accruacy. Most building contractors, whether residential or commercial, can use a 9 second theodolite without experiencing problems due to accuracy. At this distance, more errors are in the form of human errors, such as not leveling the instrument properly or taking a quick reading which lends itself to human error.

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Tripod

This levelling tripod consist of three leg. Each leg can be adjustable with any height and also distance between the legs. This is to make sure that the levelling tripod place horizontal.

Plumb Bob

A plumb bob or a plumet is a weight, for the most part with a pointed tip on the base, that is suspended from a string and utilized as a vertical reference line, or plumb-line. It is basically also known as called a "water level".

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Ranging Rod

A pole for marking positions in surveying. Ranging rod can be purchase easily in anywhere and it is made from a straight pipe.

Levelling

A leveling rod is a surveying tool used to take elevation measurements for the purpose of profiling a section of terrain. There are a number of basic designs available, including versions for optical and digital sighting and record keeping. Surveying supply companies typically sell leveling rods and accessories like cases, replacement components, and other surveying tools. Engineers, surveyors, and members of other professions that need to perform surveys receive instruction in the use of a leveling rod as part of their education.

This tool is also known as a level staff, a reference to the original design, which was simply a tall staff with measurement markings. The surveyor could place the staff in a

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location with a landmark of known height, perform a sighting for reference, and then move the staff to take a series of sightings, looping back to the original site or another known reference for confirmation at the end. While older level staffs are still in use, modern designs are more flexible and tend to be easier to use.

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DATA FIELD

ANGULAR ERROR & ANGLE ADJUSTMENTS

The sum of the interior angles in any loop traverse must equal (n-2)(180°) for geometric consistency, which means the sum has to be 360°

(4-2)(180°) = 2(180°) = 360°

Total angular error = 360°00’00’’ - 359° 41’ 20’’ = 0° 18’ 40’’

station Field angles correction Adjusted anglesA 89° 06’ 20’’ +4’40’’ 89° 11’ 00’’B 90° 26’ 00’’ +4’40’’ 90° 30’ 40’’C 88° 16’ 40’’ +4’40’’ 88° 21’ 20’’D 91° 52’ 20’’ +4’40’’ 91° 57’ 00’’Sum= 358° 100’ 80’’ 360° 00’ 00’’

359° 41’ 20’’

Therefore, error per angle = 18’ 40’’ / 4 = 4’ 40’’ per angle

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COURSE BEARING & AZIMUTH

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89° 11’ 00’’

Azimuth N

89° 11’ 00’’

180° 00’ 00’’

+ 90° 30’ 40’’

+ 89° 11’ 00’’

359° 41’ 40’’

88° 21’ 20’’

-0° 18’ 20’’

88° 03’ 00’

+ 180° 0’ 00’’

268° 03’ 00’’

91° 57’ 00’’

+ 88° 03’ 00’’

180° 00’ 00’’

Bearing

N 89° 11’ 00’’ E

N 0° 18’ 20’’ W

S 88° 03’ 00’ W

S 0° E

90° 30’ 40’’

88° 21’ 20’’

A

B

C

D

?

COURSE LATTITUDE & DEPARTURE

Cos β Sin β Lcosβ Lsinβ

station Bearing, β Length, L cosine sine latitude departure

A N 89° 11’ 00’’ E 20.30 0.014253 0.9998984 0.2893367 20.297937

B N 0° 18’ 20’’ W 55.78 0.999985 0.0053329 55.779206 0.2974705

C S 88° 03’ 00’ W 20.57 0.034027 0.9994209 -0.6999425 -20.558087

D S 0° E 55.35 1.000000 0 -55.350000 0

152.00 0.0186002 0.0373214

Accuracy= 1 : (P/Ec), typical=1:3000

Ec = [(sum of latitude)2 + (sum of departure)2 ]1/2

= 0.042P = 152.00Accuracy = 1: (152.00/0.042)

= 1: 3645

∴The traversing is acceptable

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Adjusted Latitude & Departure

Compass Rule:Correction = - [∑Δy] ÷ P x L or - [∑Δx] ÷ P x L

CorrectionAB Lat= -0.0186002 ÷ 152.00 x 20.30 = -0.0024841

CorrectionBC Lat= -0.0186002 ÷ 152.00 x 55.78 = -0.0068258

CorrectionCD Lat= -0.0186002 ÷ 152.00 x 20.57 = -0.0025171

CorrectionDA Lat= -0.0186002 ÷ 152.00 x 55.35 = -0.0067732

CorrectionAB Dep=-0.0373214÷ 152.00 x 20.30 =-0.0049844

CorrectionBC Dep= -0.0373214÷ 152.00 x 55.78 = -0.0136960

CorrectionCD Dep= -0.0373214÷ 152.00 x 20.57 = -0.0050501

CorrectionDA Dep= -0.0373214÷ 152.00 x 55.35 = -0.0135904

Unadjusted Corrections Adjustments

Station Latitude Departure Latitude Departure Latitude Departure

A 0.28933 20.29794 -0.00248 -0.00498 0.28685 20.29296B 55.77920 0.29747 -0.00683 -0.01370 55.77237 0.28377C

-0.69994 -20.55809 -0.00252 -0.00505 -0.70245 -20.56314D -55.35000 0 -0.00677 -0.01359 -55.35677 -0.01359

Check 0.01860 0.03732 -0.01858 -5.08272 0 0

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Table & Graph of Station Coordinates

N2 = N1 + Lat1-2

E2 = E1 + Dep1-2

Where:N2 and E2 = the Y and X coordinates of station 2N1 and E1 = the Y and X coordinates of station 1Lat1-2 = the latitude course 1-2Dep1-2 = the departure course 1-2

Course Adjusted Latitude

Adjusted Departure

Station N Coordinate Latitude (y-axis)

E Coordinate Departure (x-axis)

A 100.0000(Assumed) 100.0000(Assumed)

AB 0.28685 20.29296B 100.28685 120.29296

BC 55.77238 0.28377C 156.05923 120.57673

CD -0.70245 -20.56314D 155.35678 100.01359

DA -55.35677 -0.01359 A 100.0000 (Checked) 100.0000 (Checked)

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DISCUSSION

Before executing the process, we need to decide where should point A, B, C and D

laid out on the site respectively. As the number of theodolite prepared was limited,

we would have to take turn as we were sharing the theodolite. Thus, we learnt from

other groups and discussed among each other as we failed for the first attempt.

This is a closed loop traverse. The angles of the theodolite must be read from left to

right in order to obtain a more accurate reading.

The total recorded angles must be 360°. However, there was some errors occurred

and the recorded angles had difference of 18’ 40’’. Thus, we had to adjust it. Lastly,

we had to tabulate data and draw graph based on the result.

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CONCLUSION

According to the data obtained by using the theodolite, the angle obtained is not

exactly 360°. Hence, there are angular errors occurred and angles must be adjusted.

To adjust the angles, the amount of exceeding angles shall be divided into 4 set ups

and added or subtracted by the 4 angles obtained on site. With the data obtained,

we are able to produce this fieldwork report.

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REFERENCE

1) (n.d.). Retrieved June 28, 2015, from https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http://www.hayesinstrument.com/st_prod.html?p_prodid=2151&ei=wZ-PVdb4O5K3uQSI6oKYAQ&bvm=bv.96783405,d.c2E&psig=AFQjCNFFHbzBaRSpahCZwzDT3IefL-m6eA

2) Site Surveying Report 2 (Traversing). (n.d.). Retrieved July 1, 2015, from http://www.slideshare.net/Haziq1511/site-surveying-report-2-42339915?related=1

3) McMahon, M., & Fann-Im, N. (n.d.). Retrieved July 1, 2015, from http://www.wisegeek.com/what-is-a-leveling-rod.htm

4) Theodolites. (n.d.). Retrieved July 1, 2015, from http://www.engineersupply.com/Theodolites.aspx

5) Difference Between Azimuth and Bearing. (2012, December 12). Retrieved July 1, 2015, from http://www.differencebetween.com/difference-between-azimuth-and-vs-bearing/

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