1. SCHOOL OF ARCHITECTURE,
BUILDING AND DESIGN
BACHELOR OF QUANTITY SURVEYING (HONOURS)
QSB60103103946-M Site Surveying
Fieldwork Report 2
TRAVERSE
GROUP MEMBERS STUDENT ID
Liew Li Wen 0324297
Lim Kar Yan 0325602
Tan Hwee Min 0326057
Esther Chuah Ning Sie 0321422
2. 1
TABLE OF CONTENT
Content Pages
Cover Page 1
Table of Content 2
Introduction 3 - 8
Objectives 9
Data and Results 10 - 22
Discussion 23 - 25
3. 2
1.0 Introduction to traversing
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.
1.1 Types of Traverse
➔ Closed traverse: When the lines form a circuit which ends at the starting point, it is
known as closed traverse.
➔ Open traverse : When the lines form a circuit ends elsewhere except starting point, it
is said to be an open traverse.
1.11 Open Traverse
An open traverse is one which does not close on the point of the beginning. It begins at a
point of known position and ends at a station whose point is unknown. This traverse type is
not recommended because there is no geometric verification possible with respect to the
actual positioning of the traverse stations.It is commonly used for the line center survey for
highway,railroad and etc.
OPEN TRAVERSE
Image source:www.artillerysurveyors131.com.au
4. 3
1.12 Closed Traverse
A closed traverse is one enclosing a defined area and having a common point for its
beginning and end point or at a point whose relative position is known. It is commonly used
for locating the boundaries of lakes,property and etc.
There are two types of closed traverse:-
1. Loop Traverse - The starting point and the ending point of the loop are located at the
same point, a closed geometric figure called a polygon will be formed. The ending
point will be the same with the beginning point if you were to move along the sides of
the closed traverse. Loop traverse are best surveyed in a counterclockwise
direction,with interior angles ‘turned’ to the right.
Image source:files.carlsonsw.com
2. Connecting Traverse - It looks like an open traverse ,except that it begins and ends
at points (or lines) of known position (and direction) at each end of the traverse.
Deflection angles must be identified as being turned either clockwise,that is,to the
right (R) ,or counterclockwise to the (L).
Image source:jerrymahun.com
5. 4
1.2 Azimuths
The azimuth of a line defined as the clockwise horizontal angle from reference line. The
reference direction normally is from north .The range of the angle should be from 0º to 360º.
The example of the azimuth is 120º or 140º.
1.3 Bearing
A bearing of a line defined as the acute angle(<90º) from the north (N) or the south (S) end
of meridian. It has the addition designation of east (E) or west (W), whichever applies . The
angle of the bearing should never greater than 90º. The example of bearing is S60ºE or
N70ºW.
Image source:www.e-education.psu.edu
1.4 Selection of Traverse Stations
● The chosen control traverse stations need to be as close as possible to the features
or objects
● The chosen control traverse stations need to form a suitable shape.
● Cost and time of the survey will increase if too many points are established
● Sufficient control may not be provided for the survey if too few points are established.
● The ground of the survey area should be accessible where the traverse legs are
tapped.
● The length of the traverse legs are needed to be almost the same.
6. 5
1.5 Acceptable Misclosure
In common, for land surveying an accuracy of about 1:3000 is typical. The acceptable
misclosure can be calculated by using the formulae below:-
Accuracy= 1 : (P/Ec)
P= Perimeter
E= Error of closure (computed from the error in departure and error in latitude ,using the
Pythagorean theorem)
Classification First Order Second Order
(Class I)
Second Order
(Class II)
Third Order
(Class I)
Third Order
(Class II)
Recommended
spacing of
principal
stations
Network
stations 10-
15km ; other
surveys
seldom less
than 3km
Principal
stations
seldom less
than 4km,
except in
metropolitan
area surveys
,where the
limitation is
0.3 km
Principal
stations
seldom less
than 2km,
except in
metropolitan
area surveys
,where the
limitation is
0.2 km
Seldom less
than 0.1 km
in tertiary
surveys in
metropolitan
area surveys
; as required
for other
surveys
Seldom less
than 0.1 km in
tertiary
surveys in
metropolitan
area surveys ;
as required
for other
surveys
Position
closure after
azimuth
adjustment
0.04m √K or
1:100,000
0.08m √K or
1:50,000
0.2m √K or
1:20,000
0.4m √K or
1:10,000
0.8m √K or
1:5000
Table: Traverse Specifications - United States
Source: From Federal Control Committee,United States,1974.
7. 6
1.6 Traverse Computations
Traverse computations is the process of taking field measurement through a series of
mathematical calculations to determine final traverse size and configuration. These
calculations include error compensation as well as reformation to determine quantities not
directly measured.
Traditional traverse computation steps are:
1. Balance (adjust) angles
2. Determine line directions
3. Compute latitudes and departures
4. Adjust the traverse misclosure
5. Determine adjusted line lengths and directions
6. Compute coordinates
7. Compute area
The order of some steps can be changed. For example, steps 1 and 2 would be reversed for
closed link traverses with directions at both ends. Balancing angles would normally not be
done If a least squares adjustment is used at step 4.
The complete series of computations can only be performed on closed traverses. That's
because some of the steps require adjustment of errors and, as discussed before, errors
can't be identified in an open traverse.
8. 7
1.7 Outline Apparatus
Theodolites are used mainly for surveying applications. It is a
precision instrument for measuring angles in the horizontal
and vertical angles, distance, depth and etc. It is used to
identify the ground level and the ways to construct ‘super-
structure or
sub-structure. A modern theodolite consists of a movable
telescope and it is able to rotate 360 degree on a tripod stand
by the leveling system. When the telescope is pointed at a
target object, the angle of each of these axes can be
measured with great precision. The calculation of the angles is
based on the used in triangulation network and geo-location work.
Tripod stand consists of a portable three-legged frame. It is
used to provide stability by supporting the weight and
maintaining the balance of the instrument on top of it. The
three legs are moved away from the vertical centre and the leg
lengths are adjusted to bring the tripod head to a convenient
height and make it roughly level. After that screw the
instrument on it and make sure both of them are precisely
positioned.
Plumb bob is an instrument to make sure the object is
placed perpendicularly. It is a weight with a pointed
bottom that is suspended from a string to determine a
vertical line. It’s usually used to mark a point directly
under the theodolite.
9. 8
Spirit level is designed to indicate whether the surface is
horizontal or vertical. A slightly curved glass tube which
incompletely filled with either alcohol or spirit, leaving a
bubble in the tube. On a flat surface, the bubble naturally
rest in the center, the highest point.
Optical ‘plumnet is a detachable base for theodolites
to indicate the center of it over a ground station. It is
used in place of plumb bob to center theodolites and
transits over a given point due to its steadiness in
strong winds during surveying process. It can speed
up the set-up procedure and protect the theodolite
from any accident because there’s a lock below it to
screw itself towards the device using during the
fieldwork.
Ranging poles are used to mark areas and to set out
straight lines on the field. They are also used to mark
points that must be seen from a distance, in which
case a flag may be attached to improve the visibility.
Ranging poles are straight round stalks, 3 to 4 cm
10. 9
thick and about 2m long. They are usually painted with alternate red-white or black-white bands.
2.0 Objectives
● To learn the principles of running a closed field traverse.
● To enhance the student knowledge in the traversing procedure
● To be familiar with the setting up of the theodolite
● To determine the error of misclosure in order to compute the accuracy of the work
● To determine the adjusted independent coordinates of the traverse station so that they
can be plotted on the drawing sheet
12. 11
3.1 Compute the angular error and adjust the angles.
The sum of the interior angles in any loop must be equal (n - 2) (180º) for geometric
consistency;
Sum of interior angle= (n - 2) (180º)
= (4 - 2) (180º)
= 360º
Total angular error = 360º 00’ 00’’ - 359º 57’ 40’’
= 0º 02’ 20’’
Error per angle = 0º 02’ 20’’ / 4
= 0º 0’ 35’’ per angle
Station Angles Correction Adjusted Angles
A 82º 44’ 30’’ + 0º 0’ 35” 82º 45’ 05’’
B 94º 39’ 50’’ + 0º 0’ 35” 94º 40’ 25’’
C 87º 46’ 30’’ + 0º 0’ 35” 87º 47’ 05”
D 94º 46’ 50’’ + 0º 0’ 35” 94º 47’ 25”
Sum 359º 57’ 40’’ 360º 00’ 00”
13. 12
3.2 Calculate the Horizontal and Vertical Distance Between the Survey Points and the
Theodolite
Survey Points and the Theodolite
The horizontal and vertical distances between the survey points and the theodolite can be
calculated using the equations as follows:
Equation
;
D = k x S x cos2 (θ) + C x cos
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 readings
K = Multiplying constant given by the manufacturer of the theodolite,
(normally = 0 )
C = Addictive factor given b y the manufacturer of the theodolite
(normally = 0 )
14. 13
Distance A-B
Top Stadia: 1.730
Medium Stadia: 1.465
Bottom Stadia: 1.250
Top Stadia: 1.670
Medium Stadia: 1.475
Bottom Stadia: 1.280
Distance A-B = [ (K x s x Cos2 θ) + ( C x Cos θ )
= [ 100 x ( 1.730 - 1.250 ) Cos2 θ ] + ( 0 x Cos θ )
= 53.7742 m
Distance A-B = [ (K x s x Cos2 θ) + ( C x Cos θ )
= [ 100 x ( 1.670 - 1.280 ) Cos2 θ ] + ( 0 x Cos θ )
= 45.5760 m
Average distance = ( 53.7742 m + 45.5760 m ) / 2
= 49.6751 m
Distance B-C
Top Stadia: 1.520
Medium Stadia: 1.453
Bottom Stadia: 1.263
Top Stadia: 1.326
Medium Stadia: 1.260
Bottom Stadia: 1.080
Distance B-C = [ (K x s x Cos2 θ) + ( C x Cos θ )
= [ 100 x ( 1.520 - 1.263 ) Cos2 θ ] + ( 0 x Cos θ )
= 33.7420 m
Distance B-C = [ (K x s x Cos2 θ) + ( C x Cos θ )
= [ 100 x ( 1.326 - 1.080 ) Cos2 θ ] + ( 0 x Cos θ )
= 24.7060 m
Average distance = ( 33.7420 m + 24.7060 m ) / 2
= 29.2240 m
15. 14
Distance C-D
Top Stadia: 1.490
Medium Stadia: 1.272
Bottom Stadia: 1.030
Top Stadia: 1.620
Medium Stadia: 1.550
Bottom Stadia: 1.130
Distance C-D = [ (K x s x Cos2 θ) + ( C x Cos θ )
= [ 100 x ( 1.490 - 1.030 ) Cos2 θ ] + ( 0 x Cos θ )
= 49.7726 m
Distance C-D = [ (K x s x Cos2 θ) + ( C x Cos θ )
= [ 100 x ( 1.620 - 1.130 ) Cos2 θ ] + ( 0 x Cos θ )
= 46.4762 m
Average distance = ( 49.7726 m + 46.4762 m ) / 2
= 48.1244 m
Distance D-A
Top Stadia: 1.463
Medium Stadia: 1.350
Bottom Stadia: 1.189
Top Stadia: 1.826
Medium Stadia: 1.680
Bottom Stadia: 1.530
Distance D-A = [ (K x s x Cos2 θ) + ( C x Cos θ )
= [ 100 x ( 1.463 - 1.189 ) Cos2 θ ] + ( 0 x Cos θ )
= 30.9954 m
Distance C-D = [ (K x s x Cos2 θ) + ( C x Cos θ )
= [ 100 x ( 1.826 - 1.530 ) Cos2 θ ] + ( 0 x Cos θ )
= 31.9806 m
Average distance = ( 30.9954 m + 31.9806 m ) / 2
= 31.4880 m
16. 15
3.3 Compute course bearing and azimuth
Azimuth Bearing
A-B 00° 00’ 00” N 00° 00’ 00”
B-C 180° 00’ 00”
+ 94° 40’ 25”
_____________
274° 40’ 25”
_____________
N 85° 19’ 35” W
18. 17
3.4 Compute Latitude and Departure
Image source:www.cfr.washington.edu
Cos β Sin β L cos β L sin β
Station Bearing, β Length, L Cosine Sine Latitude Departure
A
N 00° 00’ 00” 49.6751 1.0000 0.0000 + 49.6751 0.0000
B
N 85° 19’ 35” W 29.2240 0.0818 0.9967 + 2.3905 - 29.1276
C
S 2° 27’ 30” W 48.1244 0.9991 0.0429 - 48.0811 - 2.0645
D
S 82° 45’ 05” E 31.4880 0.1262 0.9920 - 3.9738 + 31.2361
A
Total Perimeter (P) = 158.5115
Sum of
Latitude:
ΣΔy = 0.0107
Sum of
Departure:
ΣΔx = 0.0440
19. 18
3.5 Determine The Error of Closure
Accuracy = 1 : (P/Ec)
For average land surveying an accuracy of about 1 : 3000 is typical
Ec = [ (sum of latitude)2
+ (sum of departure)2
]1/2
= [ ( 0.0107 )2
+ ( 0.0440 )2
]1/2
= 0.0453 m
P = 158.5115 m
Accuracy = 1 : ( 158.5115 / 0.0453 )
= 1 : 3499
Therefore, the traversing is acceptable.
20. 19
3.6 Adjust Course Latitude and Departure
The Compass Rule
Correction = - [ ΣΔy ] / P x L or - [ ΣΔx ] P / L
Where,
ΣΔy and ΣΔx = The error in latitude and departure
P = Total length of perimeter of the traverse
L = Length of a particular course
Station Unadjusted Corrections Adjusted
Latitude Departure Latitude Departure Latitude Departure
A
+ 49.6751 0.0000 - 0.0034 - 0.0138 + 49.6717 - 0.0138
B
+ 2.3905 - 29.1276 - 0.0020 - 0.0081 + 2.3885 - 29.1357
C
- 48.0811 - 2.0645 - 0.0032 - 0.0134 - 48.0843 - 2.0779
D
- 3.9738 + 31.2361 - 0.0021 - 0.0087 - 3.9759 + 31.2274
A
Σ= + 0.0107 + 0.0440 - 0.0107 - 0.0440 0.00 0.00
Check Check
21. 20
Latitude correction
● The correction to the latitude of course A-B is
[ - 0.0107 / 158.5115 ] x 49.6751 = - 0.0034
● The correction to the latitude of course B-C is
[ - 0.0107 / 158.5115 ] x 29.2240 = - 0.0020
● The correction to the latitude of course C-D is
[ - 0.0107 / 158.5115 ] x 48.1244 = - 0.0032
● The correction to the latitude of course D-A is
[ - 0.0107 / 158.5115 ] x 31.4880 = - 0.0021
Departure correction
● The correction to the departure of course A-B is
[ -0.0440 / 158.5115 ] x 49.6751 = - 0.0138
● The correction to the departure of course B-C is
[ -0.0440 / 158.5115 ] x 29.2240 = - 0.0081
● The correction to the departure of course C-D is
[ -0.0440 / 158.5115 ] x 48.1244 = - 0.0134
● The correction to the departure of course D-A is
[ -0.0440 / 158.5115 ] x 31.4880 = - 0.0087
3.7 Compute station coordinates
22. 21
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
Station N Coordinate* Latitude E Coordinate* Departure
A 100.0000 ( Assumed )
+ 49.6717
129.1495
-0.0138 Start/ return here for lat. check
Start/ return here for dep. Check
(Course lat. and dep.)
B 149.6717
+2.3885
129.1357
-29.1357
C 152.0602
-48.0843
100.0000
-2.0779
D 103.9759
-3.9759
97.9221
+31.2274
A 100.0000 129.1495
* Compass - Adjusted Coordinates
Table 0f Computation of Station Coordinate
23. 22
3.8 Loop Traverse Plotted Using Coordinate ( Graph)
The adjusted loop traverse plotted by coordinates.
24. 23
4.0 Discussion
In this field work, we are required to investigate the survey method which is the closed loop
traverse. A traverse is a series of consecutive lines whose ends have been marked on the
field, and whose lengths and directions (angle, bearing, or azimuth) have been determined
from measurements. There are two types of traverse which is the closed traverse and open
traverse. We found that the close traverse gives a higher accuracy because open traverse
offers no means of checking for errors or mistakes.
First, we are exposed to the method of using the apparatus which is the electronic distance
measurement (EDM). A detailed explanation has been given by our lecturer before the work
is conducted. Four points are roughly set and was noted as station A, B, C and D. These
four points are set to form a quadrilateral shape as we are conducting the simplest closed
loop traverse.
Then, we used the theodolite to measure the angle of the station A, B, C and D and the data
is recorded for further calculations. We first start with the angle measurement at station A.
The apparatus is set up at station A, the data is collected by reading through the theodolite
on station B and D. This step is repeated by setting the apparatus on the following stations
to obtain the angle on that particular station. Both vertical and horizontal angles which are
showed on the digital panel of the theodolite have been recorded.
The stadias (top, middle and bottom) readings are recorded for calculation of the horizontal
25. 24
and vertical distances between the stations. This is known as the stadia method. The
calculation is given by the equation:
D = k x S x cos2 (θ) + C x cos
When calculating the error, we have obtained 359º 57’ 40’’ for our total interior angle, which
is 2’ 20’’ less than the optimum total interior angle of a quadrilateral (360º). The optimum
total interior angle is calculated by
𝛴 = (𝒏− 𝟐) ∗ 𝟏𝟖𝟎º
The error at each angle has been calculated and each angle is adjusted by adding 0º 0’ 35”.
Latitude and departure error is calculated then, which are 0.0107 and 0.0440 respectively.
The total error is 0.0453 which is given by equation
Ec = [ (sum of latitude)2
+ (sum of departure)2
]1/2
And so, the accuracy is calculated with equation
Accuracy = 1 : (P/Ec)
The value obtained is 1:3499 which meets the optimum accuracy for average land surveying
1:3000 and hence, our traverse survey is acceptable.
Latitude and departure are then being adjusted by using the compass rule:
Correction = - [ ΣΔy ] / P x L or - [ ΣΔx ] P / L
Lastly, a graph is plotted with the coordinates achieved for all the four stations.
There are few precautions have to be taken in consideration when using the apparatus when
measurement is conducting.
26. 25
1. Special care should be taken to avoid any situation that might result in the theodolite
being dropped or otherwise subjected to a severe jar.
2. Inspect the theodolite for loose parts and screws. Remove dust from the objective
lens and eyepiece with a lens brush and lens tissue using procedures consistent with
delicate optics. Keep the lens covered with the theodolite is not in use. Use a
sunshade to protect the lens from the direct rays of the sun.
3. The graduated circles and venires are coated with a lacquer to retard oxidation.
Avoid touching these parts. A thin film of oil applied with a lintless cloth will aid in
keeping the surfaces clean.
4. Store the theodolite in its case or other dry dust free location when not in use.
5. If the theodolite is to be taken from a cool environment to a warm one (especially in
humid conditions) allow the theodolite to warm up inside its case where it will not be
subject to condensation.
As any surveyor should understand, all measurements are in error. We may only try to
minimize error and calculate reasonable tolerances, but not eliminating the errors.
In conclusion, we have gained some useful knowledge on how a survey is done as it’s a
hand-on work that we have to conduct ourselves to obtain the data needed. It links up all the
theories we learned in class, giving us a deeper understanding as we worked practically on
field. It can be useful in the future as we know how a distance is measured in order to
construct a level building, or how a boundary of certain area is determined by this surveying
method.
It is pleased to have team members which are able to work together as a team in completing
the task given. The objectives set primarily are achieved easily since everyone in the team
gives fully support and cooperation throughout the survey work and report writing. Each
team members is willing to share their thoughts and ideas when discussion is conducted and
it’s a good attitude as we are able to learn from each other and broaden our mindset. Credits
are to be given to our lecturer as well for teaching and guiding us on how the survey work is
done and how the apparatus is used. It will be our pleasure if we are able to work together in
the next work soon.