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SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN

BACHELOR OF QUANTITY SURVEYING (HONS)

SITE SURVEYING (QSB 60103)

SEMESTER 2

FIELDWORK 2 : TRAVERSING

NAME STUDENT ID MARKS

TANG LAM YU 0324966

TEE WAN NEE 0325074

TEO CHIANG LOONG 0323762

WONG SHER SHENG 0329950

YAP CHOE HOONG 0323161

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CONTENT

NO CONTENT PAGE COVER PAGE 1 TABLE OF CONTENT 2

1.1 INTRODUCTION TO TRAVERSING 3-13 1.1 Traversing 1.2 Purposes of Traverse Survey 1.3 Advantages of Traversing 1.4 Tools Used 1.5 Types of Traverse 1.6 Components Of Traverse 1.7 Traverse Computation

2.0 OUTLINE APPARATUS 14 - 21 2.1 Theodolite 2.2 Adjustable Leg Tripod 2.3 Levelling Rod/ Levelling Staff 2.4 Optical Plummet 2.5 Bull’s Eyes Level ( Spirit Bubble ) 2.6 Ranging Rod 2.7 Plumb Bob

3.0 OBJECTIVE 22 4.0 FIELDWORK 23 – 34

4.1 Field Data 4.2 Field Average Data 4.3 Field Data – angles 4.4 Angular Error & Angle Adjustment 4.5 Adjusted Data 4.6 Course Bearing & Azimuth 4.7 Stadia Method (Distance/ Length) 4.8 Latitude & Departure 4.9 Coordinates 4.10 Area Of Traverse

5.0 GROUP PHOTO 35 6.0 CONCLUSION 36

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1.1Traversing

Traversing is a method to establish horizontal control network. It is also used in geodetic work. Traverse networks involved placing the survey stations along a line or path of travel, and then using the previously surveyed points as a base for observing the next point. Not only that, traversing also consists of a series of line connecting successive points whose lengths and directions have been determined from field measurement. Precise traverse surveys are much more practical these days with the aid of Electronic Distance Measurement (EDM) device.

1.2 Purposes of Traverse Survey

Traverse surveys are made for many purposes which includes:

Determining the position of existing boundary markers. Establish the position of boundary lines. Determine the position of arbitrary points which data may be obtained for preparing

various types of maps Establish ground control for photographic mapping Establish control for gathering data regarding Earthwork quantities in railroad

highway, utility and other construction work 1.3 Advantages of Traversing

Traverse network has many ADVANTAGES compared to other system, including:-

This system can change to any shape and can accommodate to a great deal of different terrains

Only a few observations need to be taken at each station (other survey networks require a great deal of angular and linear observations)

Free of strength of figure considerations that happen in triangular systems. Scale error does not add up as the traverse is being performed. Azimuth swing

errors can also be reduced by increasing the distance between stations.

1.0 INTRODUCTION TO TRAVERSING

FIGURE 1.1A Traversing FIGURE 1.1B Traversing

Source :https://billboyheritagesurvey.files.wordpress.com/2

010/06/andys-traverse-diagram.png

Source : http://3.bp.blogspot.com/-f3n3he-

1VSc/UXpqD1j74RI/AAAAAAAACuk/KsXLjlhY

b7M/s200/traverse+survey+.jpg

Electronic Device Measurement

(EDM)

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1.4 Tools Used

Figure 1.4A Theodolite Source :http://surveyequipment.com/media/catalog/product/cache/1/image/903be06a881aa18fc50d3dc96e8b9fba/p/r/prexiso-to2-theodolite-8234177.jpg?1496765241

Figure 1.4B Total Stations Source : https://2.imimg.com/data2/DL/YX/MY-802479/topcon-electronic-total-station-500x500.jpg

THEODOLITE

TOTAL STATIONS

STEEL TAPE

Figure 1.4C Steel Tape Source :http://surveyequipment.com/media/catalog/product/cache/1/image/903be06a881aa18fc50d3dc96e8b9fba/f/i/fisco-pacer-tape_1_2.jpg?1496781783

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1.5 TYPE OF TRAVERSE There are two types of traverse surveying, which are:

Open traverse Closed Traverse

1.5.1 Open Traverse

An open, or free traverse is called a first class traverse which starts at a known points plotted in any corresponding linear direction, but do not return to starting point or close upon a point of equal or greater order accuracy. Open traverse is sometimes being used on route surveys but they should be avoided because an independent check for errors and mistakes is not available and the only mean of verifying id to repeat all measurements and computations.

ROUTE SURVEYS

Route surveys is utilized in plotting a strip of land which can then be use route in road/ railway construction.

Figure 1.5.1A Open Traverse Source :https://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Open_traverse.png/250px-Open_traverse.png

Figure 1.5.1B Route Survey Source :

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1.5.2 Closed Traverse

Closed traverse which is called as second class traverse is a practice of traversing when the terminal point closes at the starting point. The control points may envelop, or are set within the boundaries, of the control network. It allows geodetic triangulation for sub-closure of all known observed points. There are 2 types of closed traverse which are:

Loop Traverse Connecting Traverse

LOOP TRAVERSE

Loop traverse is one enclosing defined area and have a common points for its beginning to the end. A closed geometric figure – useful in marking the boundaries of wood/ lakes or properties.

CONNECTING TRAVERSE

Connecting traverse looks like an open traverse except that it begins and ends at points/ lines of known position/ direction at each of the end of traverse

Figure 1.5.2A Closed Loop Traverse Source :http://files.carlsonsw.com/mirror/manuals/Carlson_2014/source/CGSurvey/CGTrav/Reduce_Traverse/Closed_Beg_and_End_known_Traverse.bmp

Figure 1.5.2A Closed Connecting Traverse Source : http://www.globalsecurity.org/military/library/policy/army/fm/6-2/fig5-6.gif

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1.6 COMPONENTS OF TRAVERSE To plot a traverse, bearing which acts as a direction and length of line is needed 1.6.1 Length of Each Traverse Line

Traditionally, this was don’t by using a steel band and applying a series of

correction to allow for the sagging of the tape, temperature effects and so on Length of line can be done electronically with the Surveyor using a highly

sophisticated Total Station that can measure both 1.6.2 Bearing

Bearing of a line is its orientation with respect to grid north. May be found for an initial line by starting at a station with known coordinates and orienting the Total Station with respect to another point.

The directions due to East and West are perpendicular to North-South meridian

A line may fall in one of four quadrant which are :

May be found for an initial line by starting at a statin with unknown coordinates and

orienting the Total Station with respect to another point with known National Grid coordinates whereby :

The Surveyor will locate the Total Station accurately over each traverse station in turn and will measure the horizontal angles.

These measurements are to a high level accuracy and several readings will be taken to minimise the possibilities of measurement errors.

Angles of bearing are being measured in degrees, minutes and seconds whereby a bearing cannot be more than 90 degrees.

Figure 1.6.2A Bearing Source : https://gs-blog-images.grdp.co/blogs/wp-content/uploads/2016/08/27015428/10.png

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1.6.3 Azimuth

An azimuth is a clockwise angular measurement in a spherical coordinate system, between the line and a given reference direction or meridian in a spherical coordinate system, The vector from an observer which is the origin to a point of interest is projected perpendicularly onto a reference plane. The angle between the projected vector and a reference vector on the reference plan is called the azimuth.

1.6.4 Latitude and Departure of a Line

Latitude

Projection on the North-South meridian and is equal to the length of the cosine of its bearing.

Departure

Projection on the East-West meridian and is equal to the length of the line times the sine of the bearing

Figure 1.6.3A Azimuth Source : https://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Azimuth-Altitude_schematic.svg/350px-Azimuth-Altitude_schematic.svg.png

Figure 1.6.3B Explaining Azimuth

Figure 1.6.4A Latitude and Departure Source : http://www.cfr.washington.edu/classes.esrm.304/Spring2011/Documents/Hurvitz_Schiess/procedures/images/image0002.gif

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1.6.5 Error Of Closure

Error of closure is the amount by which a closed traverse fails to satisfy the requirements of a true mathematical figure, as the length of line joining the true and computed position of the same point. The ratio of this linear error to the perimeter of the traverse. Nevertheless, it is expected that data taken from a survey will not close exactly. If the error on closure is acceptably small, the data are improved by corrections calculated from error. The method will then be explained in text further. If the closure exceeds acceptable limit, surveys has to be repeated.

1.6.6 Station Selection

Selecting a station should be precisely done to avoid increasing the work of measuring traverse which is by positioning the control traverse stations as close as possible to the features or objects to be located. Nevertheless, establishing too many points increases the time and cost of survey and establishing too few points may not provide sufficient control for the project. Selection of positions control traverse stations has to be precisely done due to the uneven varying terrains which can be an obstacles.

Figure 1.6.4A Latitude and Departure Source : http://surveying.structural-analyser.com/_internal/images/ErrorOfClosure_622x416.png

Figure 1.6.6A Selection of Station

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(n – 2)(180°)

1.7 TRAVERSE COMPUTATION

Traverse computation is the process of taking field measurement through aserioes of mathematical calculation to determine final traverse size and configuration. These calculations include error compensation as well as reformation to determine quantities not directly measured. Traverse computation steps are: 1.7.1 BALANCE AND ADJUSTING ANGLES

Before the areas of a place of land can be computed, it is necessary to have closed traverse.

The interior angle of the closed traverse should be total of

Where n is the number of sides of the traverse

1.7.2 DETERMINING THE BEARINGS AND LINE OF DIRECTIONS

Figure 1.7.1A Selection of Station Source : http://www.globalsecurity.org/military/library/policy/army/fm/3-34-331/ch5-1.gif

Figure 1.7.2A Selection of Station Source : http://www.globalsecurity.org/military/library/policy/army/fm/3-34-331/ch5-1.gif

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1.7.3 DETERMINING THE BEARINGS AND LINE OF DIRECTIONS

Latitude

- Lines with Northerly bearing – (+) LAT - Lines with Southerly bearing – (-) LAT - L cos ᵝ

Departure

- Lines with Easterly bearing – (+) DEP - Lines with Westerly bearing – (-) DEP - L sin ᵝ

BY USING BEARING

1.7.4 ACCURACY CHECK

Accuracy check or acceptable misclosure An average ratio of 1: 3000 is acceptable in land surveying

Figure 1.7.3A Latitude and Departure – Azimuth Source : https://image.slidesharecdn.com/fieldwork2ss-2-141203080515-conversion-

gate01/95/fieldwork-2-7-638.jpg?cb=1417593945

Error in Latitude

Error in Departure

Total Error =

1 : Length of Traverse/

Ec

Ec

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1.7.4 ADJUSTING TRAVERSE MISCLOSURE

Correction in Latitude Total Latitude Misclosure Traverse Perimeter

Correction in Departure Total Departure Misclosure Traverse Perimeter

1.7.5 DETERMINE ADJUSTED LINE LENGTHS AND DIRECTIONS AND COMPUTING COORDINATES

N₂ = N₁ + Lat₁₋₂ E₂ = E₁ + Dep₁₋₂ Where,

N₂ and E₂ = the Y and X coordinates of Station 2 N₁ and E₁ = the Y and X coordinates of Station 1 Lat₁₋₂ = the latitude of course 1-2 Dep₁₋₂ = the departure of course 1-2

1.7.6 COMPUTING AREA

X Length of Station

X Length of Station

Figure 1.7.4A Adjusting traverse misclosure Source : http://engineeringtraining.tpub.com/14070/img/14070_131_18.jpg

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2.1 THEODOLITE 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 it’s 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 accuracy. 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 levelling the instrument properly or taking a quick reading which lends itself to human error.

2.0 OUTLINE APPARATUS

Figure 2.1A Theodolite Source :http://surveyequipment.com/media/catalog/product/cache/1/image/903be06

a881aa18fc50d3dc96e8b9fba/p/r/prexiso-to2-theodolite-8234177.jpg?1496765241

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Like other leveling instruments, a theodolite consists of a telescope mounted on a base. The telescope has a sight on the top of it that is used to align the target. The instrument has a focusing knob that is used to make the object clear. The telescope contains an eyepiece that the user looks through to find the target being sighted. An objective lens is also located on the telescope, but is on the opposite end as the eyepiece. The objective lens is used to sight the object, and with the help of the mirrors inside the telescope, allows the object to be magnified. The theodolite's base is threaded for easy mounting on a tripod. A theodolite works by combining optical plummets (or plumb bobs), a spirit (bubble level), and graduated circles to find vertical and horizontal angles in surveying. An optical plummet ensures the theodolite is placed as close to exactly vertical above the survey point. The internal spirit level makes sure the device is level to to the horizon. The graduated circles, one vertical and one horizontal, allow the user to actually survey for angles

Figure 2.1B Side View of Theodolite Source : http://www.johnsonlevel.com/Content/files/TheodoliteParts.png

Figure 2.1C Sectional View of Theodolite Source : http://www.johnsonlevel.com/Content/files/TheodoliteParts.png

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2.2 ADJUSTABLE LEG TRIPOD ( TRIPOD STAND )

A surveyor's tripod is a device used to support any one of a number of surveying instruments, such as theodolites, total stations, levels or transits. Modern tripods are constructed of aluminum, though wood is still used for legs. The feet are either aluminum tipped with a steel point or steel. The mounting screw is often brass or brass and plastic. The mounting screw is hollow and has two lateral holes to attach a plumb bob to center the instrument e.g. over a corner or other mark on the ground. After the instrument is centered within a few cm over the mark, the plumb bob is removed and a viewer (using a prism) in the instrument is used to exactly center it. https://4.imimg.com/data4/WH/YB/MY-1658977/aluminium-tripod-for-auto-level-500x500.png

The tripod is placed in the location where it is needed. The surveyor will press down on the legs' platforms to securely anchor the legs in soil or to force the feet to a low position on uneven, pock-marked pavement. Leg lengths are adjusted to bring the tripod head to a convenient height and make it roughly level and being locked by a lever clamp ( left ) or screw (right).

Once the tripod is positioned and secure, the instrument is placed on the head. The mounting screw is pushed up under the instrument to engage the instrument's base and screwed tight when the instrument is in the correct position. The flat surface of the tripod head is called the foot plate and is used to support the adjustable feet of the instrument.

Positioning the tripod and instrument precisely over an indicated mark on the ground or benchmark requires intricate techniques.

Figure 2.2A Adjustable Leg Tripod

Figure 2.2B clamp and screw of leg tripod

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2.3 LEVELING ROD / LEVELING STAFF

A level staff, also called levelling rod, is a graduated wooden or aluminium rod, used with a levelling instrument to determine the difference in height between points or heights of points above a datum surface. It cannot be used without a leveling instrument.

Levelling rods can be one piece, but many are sectional and can be shortened for storage and transport or lengthened for use. Aluminum rods may be shortened by telescoping sections inside each other, while wooden rod sections can be attached to each other with sliding connections or slip joints, or hinged to fold when not in use.

There are many types of rods, with names that identify the form of the graduations and other characteristics. Markings can be in imperial or metric units. Some rods are graduated on one side only while others are marked on both sides. If marked on both sides, the markings can be identical or can have imperial units on one side and metric on the other.

Figure 2.3A leveling staffs

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Reading the Leveling Staff

The staff starts at zero, on the ground. Every 10 cm is a number, showing (in meters to one decimal) the height of the bottom of what appears to be a stylized E (even numbers) or 3 (odd numbers), 5 cm high. The stems of the E or 3 and the gaps between them are each 10mm high. These 10mm increments continue up to the next 10 cm mark.

To read the staff, take the number shown below the reticle. Count the number of whole 10mm increments between the whole number and the reticle. Then estimate the number of mm between the last whole 10mm block and the center of the reticle. The diagram above shows 4 readings:- 1.950, 2.000, 2.035 and 2.087.

The person holding the staff should endeavor to hold it as straight as possible. The leveler can easily see if it is tilted to the left or right, and should correct the staff-holder. However, it cannot easily be seen that the staff is tilted towards or away from the leveler. In order to combat this possible source of error, the staff should be slowly rocked towards and away from the leveler. When viewing the staff, the reading will thus vary between a high and low point. The correct reading is the lowest value.

Digital levels electronically read a bar-coded scale on the staff. These instruments usually include data recording capability. The automation removes the requirement for the operator to read a scale and write down the value, and so reduces blunders. It may also compute and apply refraction and curvature corrections.

Figure 2.3B Reading the leveling staff

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2.4 OPTICAL PLUMMET

In surveying, a device used in place of a plumb bob to centre transits and theodolites over a given point, preferred for its steadiness in strong winds. The device consists of two triangular metal plates connected at their corners by levelling thumbscrews, a bubble level, a locking mechanism and often an optical plummet. The device will be attached to the tripod and placed over the plummet. The bubble shown in Figure 2.4B (left) is being adjusted using the foot screw so that the foot screw can be in the middle of the cross hair as shown in Figure 2.4B (right)

2.5 BULL’S EYES LEVEL ( SPIRIT BUBBLE )

Spirit level is a tool that is being used to indicate how parallel (level) or perpendicular (plumb) a surface is relative to the earth. A spirit level gets its name from the mineral spirit solution inside the level. The vials in a spirit level are yellowish-green colour with additives for UV protection and maximum performance in temperatures ranging from -20ºF – 130ºF. The best spirit level is accurate to within plus or minus 0.5 mm/M, or 0.005 inches/inch or 0.029º. The next level of accuracy displayed is 0.75mm/M or 0.043º. The vial bodies of a spirit level, also referred as a bubble level can be shaped like a barrel, like rectangular block or even curved, banana-shaped, to measure slope in fractions per foot of pitch, and are mostly made from acrylic today versus glass originally. Sensitivity is an important specification for spirit level as the accuracy depends a lot on the sensitivity. The sensitivity of level is given as the change of angle or gradient required to move the bubble by unit distance.

Figure 2.4A Optical Plummet

Figure 2.5 Spirit Bubble

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2.6 RANGING ROD A ranging rod is a surveying instrument used for marking the position of stations and for sightings of those stations as well as for ranging straight lines. Initially these were made of light, thin and straight bamboo or of well-seasoned wood such as teak, pine or deodar. They were shod with iron at the bottom and surmounted with a flag about 25 cm square in size. Nowadays they are made of metallic materials only. The rods are usually 3 cm in diameter and 2 m or 3 m long, painted alternatively either red and white or black and white in lengths of 20 cm (i.e. one link length of metric chain). These colors are used so that the rod can be properly sited in case of long distance or bad weather. Ranging rods of greater length, i.e., 4 m to 6 m, are called ranging poles and are used in case of very long survey lines. Ranging poles are usually painted with alternate red-white and black-white bands. If possible wooden ranging poles are reinforced at the bottom by metal points. Another type of ranging rod is known as an offset rod, which has no flag at the top. It is used for measuring small offsets from the survey line when the work is of an ordinary nature.

Figure 2.6A Ranging Rod and Offset rod Source : http://www.civilengineeringx.com/building/bce/rod.jpg

Figure 2.6A Ranging Rod Source : https://2.imimg.com/data2/YJ/IT/MY-2739368/ranging-rod-250x250.jpg

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2.7 PLUMB BOB The plumb bob or plumb line employs the law of gravity to establish what is “plumb” (that is, what is exactly vertical, or true). You don’t have to be a physics whiz to understand that a string suspended with a weight at the bottom will be both vertical and perpendicular to any level plane through which it passes. In a sense, the plumb bob is the vertical equivalent of the line level or also called as the “water-level” The plumb consists of a specially designed weight and coarse string made of twisted cotton or nylon threads. (Masons prefer nylon because it stands up better over time to the dampness that comes with the trade.) At one end of the string the weight is affixed. Precisely machined and balanced bobs have pointed tips, and can be made of brass, steel, or other materials, including plastic. Surveyors sometimes use plumb bobs for lining up points or transferring them. Excavation and foundation contractors rely upon the plumb line, and constructing a chimney the tool can indicate whether a flue is running true vertical or veering off plumb.

Figure 2.7A Plumb Bob Source : https://cdn2.tmbi.com/TFH/Step-By-Step/display/FH04FEB_LEVTIP_07.JPG

Figure 2.7B Plumb Bob Source :

https://www.wonkeedonkeetools.co.uk/media/wysiwyg/11PB-Plumb-Bobs-David/11PB04/11PB-4-

8_TBTW_Plumb-bob_with_ring_attached_for_string_.jpg

Figure 2.7C Plumb Bob Source :

https://www.wonkeedonkeetools.co.uk/media/wysiwyg/11PB-Plumb-Bobs-David/11PB04/11PB-4-1_TB_Plumb-bob_with_labelled_parts_.jpg

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To learn the principles of running a close field traverse

To enhance student’s knowledge in traversing

To establish ground control for photographic mapping.

To enable student to identify the error and make adjustment to the data.

To enable student to get hands-on experience in the usage of theodolite.

To be familiar with types and methods of traverse surveying.

3.0 OBJECTIVE

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Theodolite

Station Station Sighted Top Reading Bottom Reading Vertical θ Horizontal θ

Height of

Theodolite

First Reading

A B 218.60 181.10 88°33'20" 0 115 mm

A D 210.60 189.40 87°40'00" 70°34'20"

Second Reading

A B 219.00 181.00 271°27'00" 0

A D 210.90 189.50 272°20'40" 70°34'00"

First Reading

B C 211.30 188.90 88°28'20" 0 116.30mm

B A 218.90 181.40 88°51'40" 102°56'40"

Second Reading

B C 211.00 188.90 271°32'00" 0

B A 218.50 181.50 271°8'00" 102°56'00"

First Reading

C D 217.70 182.30 88°39'40" 0 131.30mm

C B 211.00 189.00 87°35'40" 74°32'10"

Second Reading

C D 217.50 182.00 271°20'20" 0

C B 211.00 189.00 272°24'20" 74°32'30"

First Reading

D A 210.40 189.30 87°47'40" 0 119.10mm

D C 217.60 182.30 88°57'20" 111°56'00"

Second Reading

D A 210.50 189.50 272°12'40" 0

D C 217.50 182.00 271°02'40" 111°56'20"

4.0 FIELD DATA

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Theodolite Station Station Sighted Top Reading Bottom Reading Vertical θ Horizontal θ

A B 218.80 181.05 88°33'10"

A D 210.75 189.45 87°39'40" 70°34'10"

B C 211.15 189.40 88°28'10"

B A 218.70 182.15 88°51'50" 102°54'20"

C D 217.60 182.15 88°39'40"

C B 211.00 189.00 87°35'40' 74°32'20"

D A 210.45 189.00 88°28'10"

D C 217.55 181.50 88°51'50" 111°56'10"

4.1 FIELD AVERAGE DATA

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STATION FIELD ANGLES

DEGREE (°) MINUTE (‘) SECOND (“)

A 70 34 10 B 102 54 20 C 74 32 20 D 111 56 10

SUM 357 176 60 359 57 00

4.3 FIELD DATA

A

D

C

B

70° 34’ 10”

111° 56’ 10”

102° 54’ 20”

74° 32’ 20”

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4.1 Interior Angle = (n-2) X 180° = (4-2) X 180° = 360° Total Angular Error = 360° - 359° 57’ 00” = 00° 03’ 00” Error Per Angle = 00° 03’ 00” ÷ 4 = 00° 00’ 45” / 45” per angle

STATION FIELD ANGLE CORRECTION ADJUSTED ANGLE

A 70° 34’ 10” + 00° 00’ 45” 70° 34’ 55”

B 102° 54’ 20” + 00° 00’ 45” 102° 55’ 5”

C 74° 32’ 20” + 00° 00’ 45” 74° 33’ 5”

D 111° 56’ 10” + 00° 00’ 45”

111° 56’ 55”

TOTAL 359° 57’ 00” + 00° 03’ 00” 360° 00’ 00”

4.4 ANGULAR ERROR & ANGLE ADJUSTMENT

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STATION FIELD ANGLES

DEGREE (°) MINUTE (‘) SECOND (“)

A 70 34 55 B 102 55 05 C 74 33 05 D 111 56 55

SUM 357 178 120 360 00 00

4.5 ADJUSTED DATA

A

D

B

70° 34’ 55”

111° 56’ 55”

102° 55’ 5”

74° 33’ 5”

C

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STATION BEARING

A B C D A

A

D

B

C

70° 34’ 55”

102° 55’ 5”

111° 56’ 55”

74° 33’ 5”

180° - 102° 04’ 55” - 10° = 67° 04’ 55”

74° 33’ 5” - 67° 04’ 55” = 7° 28’ 10”

180° - 111° 56’ 55” - 7° 28’ 10” = 60° 34’ 55”

S 60° 34’ 55” E

N 10° E

N 67° 04’ 55” W

S 7° 28’ 10” W

S 60° 34’ 55” E

4.6 COURSE BEARING & AZIMUTH

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D = K x s x cos² (θ) + C x cos (θ) Where,

D = horizontal distance between survey point and instrument S = Difference between top stadia and bottom stadia

Θ = vertical angle of telescope from the horizontal line when capturing the stadia reading K = multiplying constant given by the manufacturer of the theodolite, (normally = 100) C = addictive factor given by the manufacturer of the theodolite,

(normally = 0)

DISTANCE BETWEEN A AND B

B – A = 100 x (2.187 – 1.815) x cos² (90° - 88° 51’ 50”) = 100 x (0.372) x cos² (1° 8’ 10”) = 37.185 A – B = 100 x (2.188 – 1.810) x cos² (90° - 88° 33’ 10”) = 100 x (0.378) x cos² (1° 26’ 50”) = 37.776

Average Distance = (37.185 + 37.776) ÷ 2 = 37.481

DISTANCE BETWEEN B AND C

C – B = 100 x (2.110 – 1.890) x cos² (90° - 87° 35’ 40”) = 100 x (0.22) x cos² (2° 24’ 20”) = 21.961 B – C = 100 x (2.112 – 1.890) x cos² (90° - 88° 28’ 10”) = 100 x (0.222) x cos² (1° 31’ 50”) = 22.184

Average Distance = (21.961+22.184) ÷ 2 = 22.073

4.7 STADIA METHOD (DISTANCE/LENGTH)

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DISTANCE BETWEEN C AND D

D – C = 100 x (2.176 – 1.822) x cos² (90° - 88° 57’ 20”) = 100 x (0.354) x cos² (1° 2’ 40”) = 35.388 C – D = 100 x (2.176 – 1.821) x cos² (90° - 88° 39’ 40”) = 100 x (0.355) x cos² (1° 20’ 20”) = 35.481

Average Distance = (35.388 + 35.481) ÷ 2 = 35.435

DISTANCE BETWEEN D AND A

A – D = 100 x (2.108 - 1.895) x cos² (90° - 87° 39’ 40”) = 100 x 0.213 x cos² (2° 20’ 20”) = 21.265 D – A = 100 x (2.105 – 1.894) x cos² (90° - 87° 47’ 30”) = 100 x 0.211 x cos² (2° 12’ 30”) = 21.069

Average Distance = (21.265 + 21.069) ÷ 2 = 21.167

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4.5 LATITUDE AND DEPARTURE

cos ᵝ sin ᵝ L cos ᵝ L sin ᵝ

Station Bearing, ᵝ Length, L Cosine Sine Latitude Departure

A

B

C

D

A

TOTAL ∑= 116.156 ∑= -0.023 ∑=+0.010 ACCURACY CHECK

FORMULA = 1: (∑ Length/ Ec) = 1: (116.156 / 0.025) = 1: 4646.24

Therefore, traversing is ACCEPTABLE

N 10° E 37.481

N 67° 04’ 55” W

S 7° 28’ 10” W

S 60° 34’ 55” E 21.167

35.435

22.073

+ 18.438

0.9211 + 8.596 0.3894

+ 6.509 0.1736 + 36.912 0.9848

- 10.396 0.4912

- 4.606 0.1299 - 35.134 0.9915

- 20.331

0.8711

ERROR IN LATITUDE ∑ ∆ L cos ᵝ = - 0.023

ERROR IN DEPARTURE ∑ ∆ L sin ᵝ = + 0.010

A

A’

TOTAL ERROR √0.023² + 0.010² = 0.025

EC

4.8 LATITUDE & DEPARTURE

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4.6 ADJUSTMENT OF LATITUDE AND DEPARTURE

Station

UNADJUSTED

CORRECTIONS

ADJUSTED

Latitude Departure Latitude Departure Latitude Departure

A

B C D A

TOTAL - 0.023 + 0.010 + 0.023 - 0.010 0 0 CHECK CHECK

The Compass Rule

Correction = - [∑∆y] / P x L or – [∑∆x] / P x L

Where, ∑∆y and ∑∆x = Error in latitude or in departure P = Total length or perimeter of the traverse L = The length of a particular course

4.7 COORDINATES

Station N Coordinate *Latitude E Coordinate* Departure

A 100.000 118.436 Start / return here for lat. check

+ 36.920 + 6.506

B 136.920 124.942

+ 8.600 -20.333

C 145.520 104.609

- 35.127 -4.609

D 110.393 100.000 Start / return here for dep. check

- 10.393 + 18.436

A 100.000 118.436

+ 36.912

+ 8.596

- 35.134

- 10.397

+ 6.509

- 20.331

- 4.606

+ 18.438

- 0.002 +36.920

+ 0.004 + 0.008

+ 0.007

+ 0.004

- 0.003

- 0.003

- 0.002

+ 6.506

- 35.127 - 10.393

+ 8.600

- 4.609

+ 18.436

- 20.333

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50

100

150

200

50 100 150

no

rth

, N

East, E

THE ADJUSTED LOOP TRAVERSE PLOTTED BY COORDINATES

A

N 100.000 E 118.436

N 136.920 E 124.942

N 110.393 E 100.000

N 145.520 E 104.609

B

C

D

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4.8 AREA OF TRAVERSE

AREA = ½ x {[(EA x NB) + (EB x NC) + (EC x ND) + (ED x NA)] – [(NA x EB) + (NB

x EC) + (NC x ED) + (ND x EA)] } = ½ x {[(118.436 x 136.920) + (124.942 x 145.520) + (104.609 x 110.393) + (100.000 x 100.000)] – [(100.000 x 124.942) + (136.920 x 104.609) + (145.520 x 100.000) + (110.393 x 118.436)]} = ½ x {[55945.918] – [54443.769]} = ½ x (1502.148) = 751.074 m²

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FROM LEFT TO RIGHT : YAP CHOE HOONG, TANG LAM YU, TEE WAN NEE,

WONG SHER SHENG, TEO CHIANG LOONG

5.0 GROUP PHOTO

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In this second fieldwork, a closed loop traverse survey is being carried out. The survey was done at car park. A closed loop traverse starts and ends at the same point. Due to this special characteristics, we are able to form a closed geometric figure. So we were assigned a group which consists of 5 peoples. We work as a team where one of us is recording down the data, two of us is taking the reading for the survey and another two is holding the leveling staff.

Theodolite is used to measure the angle of 4 points(A,B,C,D). We placed the theodolite at point A and the horizontal angle of point A is taken by reading the theodolite through point D to B. in order to maintain the accuracy of the reading, the readings must read from left to right. Horizontal and vertical angle are also taken down. The steps are repeated for the remaining points. Furthermore, top, middle and bottom stadia readings have also been recorded for calculation purposes.

For this second fieldwork, we need to take second attempt since we failed to get an accurate result in the first attempt. This is because we may have not get use to the equipment. For the second attempt, we enquiry our lecturer about the correct way to use the theodolite and we have successfully to get an accurate result. An average accuracy is 1:3000.

After the fieldwork have completed, we have learnt that group work and team cooperation are vital in this fieldwork. The survey could not be done smoothly if one of the group member is absence. This fieldwork let us learn some hands-on knowledge where we could not get it from the lecture. Lastly, we appreciate the help of our lecturer in this fieldwork. We hope that we can get more opportunity in the future to get more hands-on knowledge.

6.0 CONCLUSION