THE UNIVERSITY OF HONG KONG

DEPARTMENT OF CIVIL ENGINEERING

CIVL 1014 - SUVEYING AND DRAWING

Survey Camp Report-Group 2

Back row (boys), from left to right:Lau Po Man, Fu Shing Kong, Ho Cheuk Yin, Ho Chun Yin, Yin Yan Kit, Ng Chin Him,Yim Yu Wai,Lam Chi Ho,Front row (girls), from left to rightChan OiKwai,Chea Man Shan, Kwok Wing Man

Date: 19-11-2012

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1. Introduction 1.1 Site description

The assigned area for our group is Zone 2 which is located on a sloping area. The zone is generally divided into the upper and lower part by a footpath.Upper part of the zone consists of two buildings. One of the buildings situated next to the major footpath. It houses the washrooms and a few guestrooms. Within this building, there is a corridor leading to a staircase that link to the major footpath. Behind this building is a slope with staircase leading to the second building which is the janitor’s dormitories.On the other hand, lower part of the zone covers the BBQ area which sits on a slope. There is a small path along the slope going through the BBQ area.

1.2 Summary of the survey schemeThe surveying camp was held successfully from 29/10/2012 to 31/10/2012 at the Kadoorie Institute – Shek Kong Centre (KISK). The aim ofthis camp is to collect data for the preparation of a 1 to 200mapfor the assigned zone. Several surveying techniques were employed including leveling, traversing, detailing and contouring.

Within the assigned zone, 8 secondary vertical and 12 horizontal control stations were set. Reduced level and coordinates of these secondary stations were determined by closed-loop leveling and traversing respectively. These control stations with known reduced level and coordinates werethenserve as a framework for contouring and measurements of all non-removable and permanent features in detailing.

Moreover, there was a setting out exercise on the third day. Two control points were chosen by the demonstrator with known coordinates. With coordinates of the two given points together with a computer program prepared before the camp, coordinates of other points of the required pattern was computed. With the coordinates, the corresponding pattern was then drawn on the ground using techniques of detailing and traversing.

The route for levelingof secondary vertical control stations and the route for traverses of secondary horizontal control stations are shown in Figure 1 and 2 respectively.

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Fig.1 Vertical Secondary Control Stations

Fig.2 Secondary Horizontal Control Stations

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2. Complete Set of Data, Calculations, Adjustment and Results 2.1 Secondary Vertical Control Stations

Eight secondary vertical control stations have been set up across the BBQ area of Zone 2. Reduced levels of the control points were determined by the Rise and Fall Method and the final closing error was determined and compared with the accuracy requirement ( , where x is the smallest reading one can take from the staff and n is the number of Foresight Readings taken). As the closing error was within the accuracy requirement, it was evenly distributed to each staff point to calculate the adjusted reduced level.

i) Data of Leveling

Staff Point Backsight (BS)

Foresight (FS) Rise Fall Reduced Level (mPD)

VP3 1.3684 172.084 (Given)C1 0.8376 1.2801 0.0883 172.1723T1 0.4222 1.6766 0.8390 171.3333C2 1.0429 2.1081 1.6859 169.6474C3 0.4821 2.0686 1.0257 168.6217C4 0.0337 2.5075 2.0254 166.5963T2 0.5447 2.5818 2.5481 164.0482C5 3.0118 2.0063 1.4616 162.5866T3 1.9025 0.4682 2.5436 165.1302C6 0.9314 1.2992 0.6033 165.7335C7 3.0887 1.3738 0.4424 165.2911T4 3.4817 1.0730 2.0157 167.3068C8 3.8468 1.2324 2.2493 169.5561

VP3 1.3189 2.5279 172.084SUM 20.9945 20.9945 10.0281 10.0281

ii) Calculations and AdjustmentsSmallest reading that can be taken from the staff (x) = 0.0001Number of foresight reading taken (n) = 13Accuracy Requirement = = =

Closing Error = Rise – Fall = 10.0281 – 10.0281 = 0.0000mAs the closing error is zero, no adjustment can be made to the reduced levels obtained. However, errors may still present in the fieldwork. Just that they happened to cancel out each other to give zero closing error.

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2.2 Secondary Horizontal Control StationsThe following list of tables show the field data of building side and slope side.

First, the angular misclosure was first found out through formula. The

acceptable angular misclosure is for two repetition angular

misclosure. If the total resulted angular misclosure is less than the above maximum value, it is accepted and then correction per angle will be obtained by dividing total correction by number of stations. The total correction will be distributed equally to every angle resulted. However, if the angular misclosure is not acceptable, it will be measured again.

After adjusting angles, the latitude and departure errors were computed. According to the two errors, the linear misclosure was found. The coordinates of secondary point will be adjusted by bowditch’s method, if the resulted fractional linear misclosure is not larger than precision 1: 5000.

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Calculations, Adjustments and Results of Traversing (Building Side)

STATION

LEFT HAND ANGLE (LHA)

ADJUSTMENT

ADJUSTED LHA E N

DEG MIN SEC SECDEG

MIN

SECCoordinate of

A5829783.874

832293.589

A4 137 11 60 0.94137 12 0.94

Coordinate of A4

829813.692832328.89

9A5 72 25 17.5 0.94 72 25 18.44 dy -36.31

H1 103 28 30 0.94103 28 30.94

dx-

29.818

H2 266 23 2.5 0.94266 23 3.44

WCB

220.18

H3 88 32 23.5 0.94 88 32 33.44H4 185 17 50 0.94 185 17 50.94H5 93 9 55 0.94 93 9 55.94H6 133 30 45 0.94 133 30 45.94

TOTAL 1079 59 52.5Theoretical 1080 0 0ERROR =

(total angle-180x((number of stations)-2))-7.5

ALLOWABLE ERROR (n=5) +/-8.00

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LINE

BACK

WCBDIST.

COORINATE DIFFERENCES

COORDINATES

ST

STATIO

NLHA

CALCULATED

ADJUSTMENTS

ADJUSTED

E NLIN

EFOR

DEL. E

DEL. N

dE dNDEL. E

DEL. N

DEGREE

RADIA

N(M)

A4-A5

220

10

47.52

220.1799

3.8429

46.2195

-29.820

-35.313

-0.005

0.001

-29.825

-35.312

829813.692

832328.899

A4

A5- 4 1 47

7

A4 0 0.52

A572

25

18.44

A5-H1

112

36

5.95

112.6017

1.9653

20.6875

19.099

-7.951

-0.00

2

0.000

19.096

-7.950

829783.867

832293.587

A5

H1-A5

292

36

5.95

H1103

28

30.94

H1-H2

36

436.89

36.0769

0.6297

9.547

5.622

7.716

-0.00

1

0.000

5.621

7.716

829802.9629

832285.637

H1

H2-H1

216

436.89

H2 26

23

3.44

8

6

H2-H3

122

27

40.33

122.4612

2.1374

8.243

6.955

-4.424

-0.00

1

0.000

6.954

-4.424

829808.584

832293.353

H2

H3-H2

302

27

40.33

H388

32

33.44

H3-H4

31

013.77

31.0038

0.5411

12.36025

6.367

10.594

-0.00

1

0.000

6.365

10.595

829815.538

832288.929

H3

H4-H3

211

013.77

H4185

17

50.94

H4-H5

36

18

4.70

36.3013

0.6336

23.81625

14.100

19.194

-0.00

3

0.000

14.097

19.194

829821.903

832299.524

H4

9

H5-H4

216

18

4.70

H593

955.94

H5-H6

309

28

0.64

309.4668

5.4012

17.69175

-13.658

11.245

-0.00

2

0.000

-13.660

11.246

829836.001

832318.718

H5

H6-H5

129

28

0.64

H6133

30

45.94

H6-A4

262

58

46.58

262.9796

4.5899

8.713

-8.64

8

-1.065

-0.00

1

0.000

-8.649

-1.065

829822.341

832329.964

H6

A4-H6

     

A4              82981 83232 A

10

3.692 8.899 4

TOTAL147.278

0.016

-0.003

FRACTIONAL MISCLOSURE

1:8812.045

MAX. ALLOWABLE LINEAR MISCLOSURE

1:5000

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Calculations, Adjustments and Results of Traversing (BBQ Side)

STATION

LEFT HAND ANGLE

ADJUSTMENT

ADJUSTED LHAE N

DEG MIN SEC SEC DEG Min SecCoordinate

of A5829783.874 832293.589

A4 91 52 35 -1.25 91 52 33.75Coordinate

of A4829813.692 832328.899

H7 157 8 45 -1.25 157 8 43.75 dy -35.31H8 152 38 57.5 -1.25 152 38 56.25 dx -29.818H9 175 45 32.5 -1.25 175 45 31.25 WCB 220.18H10 36 43 20 -1.25 36 43 18.75H11 204 40 35 -1.25 204 40 33.75H12 81 10 27.5 -1.25 81 10 26.25Total 900 0 12.5

Theoretical 900 0 0.0ERROR = (total angle-180x((number of

stations)-2))12.50

ALLOWABLE ERROR (n=5) +/-9.35

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LINE BACK

WCB DIST.

COORINATE DIFFERENCES COORDINATES

STSTATION LHA

CALCULATED

ADJUSTMENTS

ADJUSTEDE N

LINE FOR DEL. EDEL.

NdE dN

DEL. E

DEL. N

13

DEGREE

RADIAN

(M)

A4-H12 205 38 12.52A4 91 52 33.75

A4-H7 297 30 46.27 297.5129 5.1926 10.3252

5-9.158 4.770 0.001 0.000 -9.156 4.770 829813.692

832328.899

A4

H7-A4 117 30 46.27H7 157 8 43.75

H7-H8 274 39 30.02 274.6583 4.7937 5.657 -5.638 0.459 0.001 0.000 -5.638 0.459 829804.536832333.66

9H7

H8-H7 94 39 30.02H8 152 38 56.25

H8-H9 247 18 26.27 247.3073 4.3163 17.0875 -15.765 -6.592 0.002 0.000 -

15.762 -6.592

829798.8984

832334.128

H8

H9-H10 67 18 26.27H9 175 45 31.25

H9-H10 243 3 57.52 243.0660 4.2423 5.36575 -4.784 -2.430 0.001 0.000 -4.783 -2.431 829783.136832327.53

6H9

H10-H9 63 3 57.52H10 36 43 18.75

H10-H11 99 47 16.27 99.7879 1.7416 13.8692

513.667 -2.358 0.002 0.000 13.669 -2.358 829778.353

832325.105

H10

14

H11-H10 279 47 16.27H11 204 40 33.75

H11-H12 124 27 50.02 124.4639 2.1723 17.072 14.076 -9.661 0.002 0.000 14.078 -9.661 829792.023832322.74

8H11

H12-H11 304 27 50.02H12 81 10 26.25

H12-A4 25 38 16.27 25.6379 0.4475 17.5392

57.589 15.812 0.003 0.000 7.591 15.812 829806.101

832313.087

H12

A4-H12      A4      

        829813.692832328.89

9A4

TOTAL 86.916 -0.012 0.000 FRACTIONAL MISCLOSURE 1:6988.613

MAX. ALLOWABLE FRACTIONAL LINEAR MISCLOSURE

1:5000

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2.3 Setting OutIn the survey camp, each group was required to draw a circle with radius of 2m and a star with its five vertexes resting on the circle at a designated area with one of the vertex pointing to North. All apparatus were not to be put inside the circle. The apparatus that each group was able to use were a total station, a theodolite, a prism, a prism pole and two tripods.

Angle-angle method was used in the setting out. Firstly, a random point in the designated area was selected as the centre ( C ) of the circle. With the coordinates of the two known points (A,B) , the coordinate of C was found by the distance between A and angle CAB, CBA. The coordinate for other point is then calculated from basic trigonometry of start. Afterwards, using cosine law the all angles of the points from A and B with respect to B and A are found. Then by using the angles and the prism with maintain the angles from B and A, the actual locations of the points could be found out.

i) Input data

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East: X; North: Y To be inputResult

X Y X Y829806.1 832313.0869 829783.874 832293.6

29.56670174Delta X Delta Y arctan(X/Y)

-22.2266 -19.4979 48.74170274

3 48 25 3.806944

X Y Radius829793.3 832300.2178 2

Distance A-H118.179

Zone 2 Setting Out Programme

Coordinate of H12 Coordinate A5

Angle Between H1-H2 & North, WCB228.7417027

In DEG, MIN, SEC

Coordinate of A

Distance H1H2

Angle A-H1-H2, WCB3.806944444

Angle Between A and North, WCB224.9347583

X

Coordinate

Y

Coordinate

Distance

H1H2

Distance

Respect to

H1

Distance

Respect to

H2

Angle

North_

Point_Center

A5 H12A5

TheodoliteH12 Total Station

Point A 829793.2608 832300.2178 29.5667 18.179 11.49138 0 0.105229 6.029157 3 48 25 6 1 45

Center 829793.2608 832298.2178 29.5667 19.64567 10.46598 n/a 0.261966 15.00956 7 55 49 15 0 34

Point 1 829794.4363 832299.8358 29.5667 17.65352 12.27132 36 0.186003 10.65721 7 23 9 10 39 26

Point 2 829795.1629 832298.8358 29.5667 17.96462 12.44859 72 0.285018 16.33035 11 14 7 16 19 49

Point 3 829795.1629 832297.5997 29.5667 18.96012 11.98017 108 0.37872 21.69903 13 30 37 21 41 57

Point 4 829794.4363 832296.5997 29.5667 20.19608 10.98304 144 0.442412 25.34833 13 27 47 25 20 54

Point 5 829793.2608 832296.2178 29.5667 21.19974 9.747901 180 0.447036 25.6133 11 27 55 25 36 48

Point 6 829792.0852 832296.5997 29.5667 21.63928 8.745745 216 0.368651 21.12214 8 22 28 21 7 20

Point 7 829791.3586 832297.5997 29.5667 21.38171 8.491518 252 0.228168 13.07307 5 9 14 13 4 23

Point 8 829791.3586 832298.8358 29.5667 20.50412 9.140505 288 0.108689 6.227433 2 46 18 6 13 39

Point 9 829792.0852 832299.8358 29.5667 19.28791 10.31727 324 0.069735 3.995549 2 8 10 3 59 44

Point 10 829793.7098 832298.8358 29.5667 18.88454 11.14772 36 0.230052 13.18099 7 44 9 13 10 52

Point 11 829793.9873 832297.9817 29.5667 19.36231 11.02609 108 0.31033 17.78058 10 0 52 17 46 50

Point 12 829793.2608 832297.4538 29.5667 20.23003 10.15126 180 0.329512 18.87967 9 20 40 18 52 47

Point 13 829792.5342 832297.9817 29.5667 20.30305 9.710567 252 0.250679 14.36285 6 48 50 14 21 46

Point 14 829792.8117 832298.8358 29.5667 19.48558 10.36397 324 0.189257 10.84361 5 44 34 10 50 37

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3. Special C ircumstances E ncountered and S olutions T aken 3.1 Leveling

After completing the whole levelingloop for the first time, the closing error obtained was determined to be +3.861m which was much larger than the accuracy requirement in this loop.As a result, the work had to be repeated. This time, digital level was used and closing error of the second loop was found to be zero.

There are two main reasons behind the failure in the first measurement after evaluation. Firstly, the upper and lower stadia were not recorded that made tracing back errors difficult. Secondly, backsight readings might have beenwronglyrecorded as foresight readings in the field book and vice versa.

3.2 ContouringContouring was only performed for the lower part of the assigned zone– the BBQ area as it was difficult and dangerous to perform fieldwork for the upper part of the site due to its densely planted steep slopes.

In the proposal, radiating line method was proposed to be used. However, this method is quite time consuming especially in a rainy day. Additionally, there was an apparatus constraint that no spares theodolitewas available. Therefore,gridding was employed and interpolation was used to give the contour lines.

The adopted procedures were:(1) The target slope area was divided into grids of known dimensions.(2) A point was then selected as the centre point which was intervisible

with a secondary control point and corners of grids assigned in the previous step.

(3) The level was placed at the centre point and backsight of the secondary control station was measured for the calculation of the height of collimation of the level.

(4) Staff readings of corners of the assigned grids were measured and recorded.

(5) Reduced levels of the corners of the gridswerecalculated using the reduced level of the secondary control point, the height of collimation and the staff readings.

(6) Steps (1) to (5) were repeated for slopes that have not been covered.

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(7) Contour lines (with 1 meter vertical interval) were drawn by interpolation of the reduced levels obtained.

3.3 TraversingWhen obtaining set angles with a large deviation of reading on the four readings, it indicated that errors existed in the measurement. To solve the problem, the other person should be responsible to take readings and check for data in order to minimize the errors.

3.4 DetailingOn day 2, an advanced instrument – electrical theodolitewas given to our group to carry out detailing work. This theodolite was much more convenience than total station because it made use of laser to focus the points, i.e. no more prismswere needed. The angle and distance were obtained directly from the instrument. The accuracy of results was higher than that of the total station.

4. Comparison B etween the S cheduled and R evealed progress, and R easons for the D elay A ssociated

On the first day of survey camp, the whole group gathered in HKU at 9 am. After arriving the camp site,three sub-groups were divided. Lower BBQ loop has been performing detailing and leveling by sub group 1 and 3, while upper building loop has been performing horizontal traversing. Work had been carrying on until 1800. On the second day of survey camp, contouring and traversing had been performing in the BBQ loop while building and BBQ had been performing detailing. Work had been carrying on until 1750. On the third day of survey camp, as contouring had not been completed, setting out had been started by sub group 1 and 2. However, setting out tasks was time consuming and our group had some problems about the programme. All tasks completed about 1600.

The revealed progress turned out to be quite similar to the scheduled progress. However, the progress had turned out to be tight, using up nearly all the emergency time. The following would be the reasons for the delay:

4.1 Raining and Instrument ErrorsDuring day 2 , the weather was extremely bad as there was heavy rain which seriously affect our efficiency. The rainy weather blocked the sunlight which

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causes more difficulties while using the total station and theodolite. Also , the rainy weather causes some difficulties in setting up the tripod as the ground become wet and some soil may settle.

4.2 Time Crush with Other GroupAs our group and group 1 had the same area that needed to be surveyed. Thus, our group and group had some time crushes of using some turning points. Internal crushes were also an issue, for example, detailing and leveling group crushed on BBQ loop on first day.

4.3 Error of MeasurementDue to some mistakes made in leveling and transverse, some of the secondary control points need to be done again to ensure the data collected is correct. Also, it was unclear which station had mistake. Most of the secondary control points needed to double check and re-measure until the error calculated fit the limits from the instruction.

4.4 ProgrammeProblem The setting out programme that we were using was incorrect, thus some of time was wasted to correct the programme into a proper one. Different approaches and programs has been used for trying to correct the program.

5. Comments and Suggestions 5.1 Traversing

(1) Some detailing points are too closed to the total station and there are difficulties in reading the target on the prism. The position of the total station has to be revised after several detailing measurements to ensure the total station is still positioned exactly on the secondary control point.

(2) The light condition become very poor in the late afternoon in the covered area in front of the office building, which make the detailing measurement more difficult for the total station. The same person should be responsible for taking each set of readings to reduce the errors due to personal judgement.

(3) During detailing, the position of the total station was found to be slightly displaced from the secondary control point after a certain period of measurement. The recorded data have to be checked immediately to ensure consistency. The legs of the tripod of the apparatus should step on

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a chosen roughly ground surface to prevent any undesirable movement of the apparatus.

(4) The prism pole cannot be placed strictly still and some errors will be made in the measurement. The tripod of the apparatus after setting up should be monitored to ensure no group-mates would accidentally kick or move the tripod. Moreover, caution should be taken for the operator of the total stations in order to minimized the undesirable movement of the apparatus.

5.2 Leveling(1) There were some errors in the first day result and the measurement had to

be redone on that day. The main problem encountered in using level was the removal of parallax.

(2) The staff holder should ensure that the circular bubble was at the centre when viewing the bubble right up above.

(3) The distance of backsight and foresight should be kept nearly the same. Otherwise the collimation error would not be cancelled out.

(4) The distance between the staff and level shouldn’t be too large. Otherwise the reading on staff would be too small, resulting in greater error.

(5) The uppermost part of the staff should not be used as the error was increased significantly due to greater vibration of staff.

(6) The same person should be responsible for taking each set of readings to reduce the personal errors as different people have different sighting.

5.3 Setting Out(1) Manual methods of tape sticking and marker labeling were deployed in

recording the positions of relevant points to allow greater flexibility in angle measurements. However, human errors involved accounted for high uncertainties which can otherwise be prevented by using prisms;

(2) Precision of total station and theodolite in angle measurements are deviated to a certain extent, where preference is always given to the former apparatus. However, both of them were used simultaneously to specify a point without compromising their controversy in accuracy;

(3) The assumed level site condition was intervened with slight irregularities on ground surfaces;

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(4) All the task points established were solely based on the known coordinates of total station and theodolite without subjecting to a checking mechanism.

(5) Some errors were found in the excel programs used to generate the coordinates of the detailing points. The excel programs were changed to accommodate our situation on the first night. It is suggested that the excel program should be rechecked by all the members in the group before the survey camp in order to prevent this.

5.4 Detailing(1) Ambiguities were risen for the programming treatment of raw data, in the

sense that the equation for computing point coordinates did not take into account angles larger than 180 (hence the possible locations of data points were not exhausted).

(2) Occasional strong wind was encountered during the measurement process, such that the staff was subjected to slight movement from time to time. Deviations were expected for the readings;

(3) Features distributed in the sitting-out area were often embedded or hidden by nearby vegetations, inducing difficulties for theodolite line of sight. In addition, some items are closely placed and can barely be distinguished.

(4) Particular selected features could not be viewed simultaneously from two reference point, which were essential for angle determination under the 2 repetitive method.

(5) Staff positioning could not be strictly vertical at restrained terrains (e.g. hillsidemanholes and signposts), giving rise to uncertainties in taking measurements.

6. Conclusio n Throughout the survey camp, we had made use of the Total Station, the Theodolite and the level to carry out the surveying work in the field. The coordinates and reduced level at different points of our zone was found and plotted as a map using AutoCAD. In this map all the features in our zone including all the buildings, slopes, staircases had been shown. After surveying camp, we have not only gained some hand-on experience on practical surveying work, but also learnt the limitations of practical surveying work in field. All these helped us to have a more understanding in the subject of surveying.

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7. Appendix

AppendixA - Fieldbook

YIN Yan Kit (2010261626)

I was the leader of group 2. Coordinating and division of labor was my main goal and responsibility. During pre-camp, we have mainly divided the area into two loop with BBQ and building loop. Firstly, in order to connect A4 and A5, we plan to have a loop in the slope. However, in the survey camp due to the bad weather condition, we form our loop excluding those in the slope for safety. Also, we have some misunderstanding for the detailing and added some more redundant point in the loop, in which we finally eliminated them.

In the surveying camp, I was belonging to the traversing group. While we started traversing, the error was quite large with some up to a minute between the two repetitions. There was also a significant difficulty regarding reading of H5 from H6 as there are insufficient of light. At the end of first day, we managed to finish the building loop for building loop and start quite a few for BBQ loop. The data for building loop shows quite a significant error for angular disclosure. For the other group process, detailing group was a little bit too slow and leveling have finish the leveling with acceptable error.

On the second day, this was a heavily rainy day especially at the morning. Detailing group had started working in the morning while the traversing and leveling decided to wait. Traversing finished the BBQ loop and re-took some of the building loop at the end of the second day. The progress was quite smooth as we are more familiar with the equipment. The lack of light for H5 was finally dealt with the help of torque for providing light to prism. Detailing group and leveling also had finished their responsible part.

On the third day, we all started for the setting out. However, the program was found to have error despite the simple check at the end of second day. Quite a lot of times were spent for checking for the program. Different method was used so as to find a way to work. Finally, an angle-angle method was used with the corrected program.

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All in all, the survey camp was quite successfully done. I needed to thanks for all our members for cooperation, and also the tutors for help. FUShing Kong Anson (3035011905)

I was in group 2 in the surveying camp, which was responsible for zone 2. In my group, I was in the traversing team, which was responsible to find out the coordinates of the secondary horizontal control stations. There were two traversing loops that were needed to be done. They are A5-H1-H2-H3-H5-H6-A4-A5 and A4-H2-H8-H9-H10-H11-H12-A4. During the traversing loop, I was to set up the total station and operate the total station to get the angle and distance required.

The first day 29-10-2012At around 10 am in the morning, I and my group mates arrived at the camp site. At first, we did not know what to do and so we did not start the work until around 11 am. Although I have attended the training session of using the equipment, we still cannot use the equipment efficiently due to the unskillfulness of us using to the equipment. So as a result, we had only done 3 traversing points during the whole morning. In the afternoon, as we became more and more skillful, we were able to finish one and a half traversing loop and catch up with the working schedule by the end of the day. In the night, my group mates computed the result and inputted the data of the loop finished during the day and found out that the angular misclosure was 1 degree, which is too much. So I and my traversing teammates discussed and decided to re-measure a few traversing points that we deemed to be not accurately measured.

The second day 30-10-2012It was a rainy day. We started work at around 11 am due to rain. We quickly finishedthe second loop in the morning and calculated the angular misclosure of the second loop. We found out that the angular misclosure was 4 degree. During lunch, wedecidedthat we should re-measure the first loop then re-measure the second loop.In the night, we calculated the angular misclosures by using the re-measured dataand finally they are within the acceptable range.

The third day 31-10-2012As our team had already done all the traversing work and our group mates has also finished their work, we started to do the setting out early at around 10 am. We got a theodolite, a total station and a prism to do the setting out. However, we were not able to find out the north point due to that we did not input data correctly. Until afternoon when we finally got the setting out program working properly, we finished

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the setting out quickly at 4pm. Then we waited until 6:30 pm to leave the camp site.

LAU Po Man (3035009964)

In the surveying camp, I belonged to group 2, and was assigned into the traversing team. The leader of whole group was Kelvin Yin, while the leader of our traversing team was Anson Fu. The task of our team was to traverse the two loops, which we designed in preparation stage, in zone 2. To be precise, my duty in traversing team was setting the tripods for total station and prisms, and to make sure the pods are in horizontal level and minimize the error caused. 29/10In this first morning of surveying camp, we started with the upper loop. However, as all members are still not skilful enough in handling our equipment, the process was rather slow. Plus it was light raining, our schedule was further disturbed. After working for two hours before lunch, only 4 points had been finished.Then, after the lunch, the skill of setting up tripods and taking reading of total station was improved. Although there was trouble as another group was studying the same area, the process was still far much better than that of the morning. Before dinner, the upper loop was finished and about half of the BBQ loop was also done. The data of that day was entered at night and found that there was error in the upper loop that needed to be solved next day.30/10The next day was still a rainy day and it in fact rained quite heavy in the morning. We are forced to stay indoor and cannot precede our work. Traversing task was continued at once when the rain become smaller as we would like to make sure there is enough time in case of any error that a second time of traversing of loop is needed. The BBQ loop was first finished, and then some points of upper loop was tested again as it was thought that point was the main reason the error of the upper loop.Data was inputted and acceptable results are collected from both loops. After finishing works of traversing, we assisted the detailing team.31/10For the last day, as traversing was already finished, setting out was the only task on that day. Again, my main role was setting up the tripods and make sure they are in horizontal level. At first, it was found that the original programme had problem that could not give out correct coordinates. It was not solved until the lunch. A back up programme was used, which was based on angle-angle method instead of distance-angle method that was used initially. The task proceeded smoothly afterwards, and completed around four o’clock.

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LAM Chi Ho Leo (3035012155)

In the surveying camp, I was assigned into the detailing group working with my teammates including Mike, York and Bosco. Our main objective and role in this camp is to find out all the permanent and non-removable objectssuch as lamppost, drainage, fence and buildings in our assigned area which is zone 2. Before the surveying camp, we had already communicated with the traversing team to set up the secondary horizontal control stations in the best location so as to make us easier to find out all the objects.1 st Day On the first day, after picking up the equipment, the first thing we did was the planning of the detailing work and division of labors. Our team decided to separate our zone into BBQ area and non-BBQ area. Then, we planned to finish the BBQ part in the first day and the rest would be done in the second day. We had totally four people in our group and I set up and used the theodolites to observe the readings, Mike marked down the reading I observed on the map we drafted, York held the staff and Bosco used meter rule. Since we spent some time to get used to the instruments and face some difficulties in do detailing in such a large and steep BBQ area. Therefore, we had just finished half of the detailing work in the first day.2 nd Day In the morning, since we had already got familiar with each of our post the equipment we used, we did faster and faster in the non-BBQ area. However, the heavy rain and foggy weather slow down our process or even made things worst. Since we could not stop and had no choice to keep doing detailing (otherwise it was impossible to finish all the detailing before we leave the camp), we found that the theodolites got malfunctioned due to the water entered it and we then stopped our work inevitably.In the afternoon, we seek “saiwaigor” for help and he would arrange a total station for us when other group finished using it. We waited until 3pm for the total station and this is much faster than the theodolites when doing detailing because it has digital display and quick response. Thus, we spent only two hours to finish all the detailing work.3 rd Day We used the whole day for doing setting out. Since we have prepared an excel program for the setting out, it was quite straightforward for this part and I was responsible in using the theodolites to take the reading. Although we initially found

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the program got something wrong, but we whole team stuck together to find out the problems, then we quickly start doing the setting out again and finished before 4pm.

CHEA Man Shan (3035014074)

In the survey camp, I was a member of team 1 of group 2 being responsible for the leveling and contouring work and worked with my group mates Chan OiKwai(Aki) and Kwok Wing Man (Vivian).

In the first day,after collecting the equipment, we immediately started our leveling. We first located our secondary vertical control points by placing coins on ground. Then, we started doing the leveling loop. For looping,I worked as an observer and data recorder, Vivian was responsible for holding staff and Aki took part in checking data and taking photos.

We finished our first loop within 4 hours; however unfortunately,we found out that there was nearly 4 m closing errorswhich was far from satisfaction. As a result, we had to repeat our work. This time, we had a chance to work with the digital level. With its high efficiency, we finally finished our second loop with zero closing error before the dinner.

In the second day, because we had already finished the leveling loop, we began to work on contouring.However, due to heavy rain, work started at 10 am. To minimize the work load and save time,we employed gridding and used the interpolation method to give the contour lines. Before 5 pm, we had already finished 2 lines, one near the fence and one at the upper BBQ site, however, while we worked for our 3rd line,the rain suddenly became heavy and the sky turned black that leveling was no longer possible, so we had to stop our work.

In the third day, thanks to god, the weather was good so that we could continue the contouring work at 9 am and could finish it before lunch. Then we worked on the setting outexercise. As the programme wrote did not run probably, we helped to calculate the coordinates of the points by hands based on the two reference points and their angles. Luckily, the bugs were finally detected and debugged. Otherwise, we had to do tedious mathematics for long time.

In conclusion, our surveying camp was quite successful as all the works were finished on time.

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KWOK Wing Man (3035009653)

In the survey camp, I was in charge of team 1 which was responsible for leveling and contouring. There were three members in the sub-group including me, Chea Man Shan Mandy and Chan OiKwai Aki. Main duty of our group is to determine the reduced levels of the eight secondary vertical control points across lower part of the assigned zone, the BBQ area and to carry out contouring for slopes within the zone.

On the first day of arrival, we began our work right after the apparatus collection. I was responsible for holding the staff, Aki observed and took record while Mandy took photos and checked the readings taken for accuracy. We first worked on the primary control station VP3 while the other teams located the secondary control points. After learning the exact location of the secondary points, we carried out our work smoothly and completed the first loop. However, the closing error of this loop was found to be

+3.861m which was way larger than the allowable accuracy requirement ( )

that the whole measurement for the loop was repeated.

For the second measurement, we were given the chance to use the digital level. Using the digital level, our speed of work was greatly increased that we were able to complete the loop and calculate the closing error before dinner and decided to perform contouring on the second day. In this measurement, the closing error was determined to be zero. We inputted the data into the computer and prepared the program for computing all the reduced levels at night.

On the second day, it was raining heavily but as we were concerned about the limiting time for contouring, we began our work before noon. We employed the gridding approach instead of the radiating line method as proposed for contouring. Reasons behind this were that the proposed method is time-consuming and there wasn’t a theodolite for us to apply the method. Without a tape, we first divided the target area with railings at the top of the slope and completed half of the work as it got darker.

On the third day, we quickly finished the remaining contouring work and joined the other teams on the setting out practice. The practice was not carried out as smooth as expected with bugs in the prepared programme. With the other teams trying to fix the program, our team attempted to work out the coordinates by hand. Luckily, the

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program was fixed and we were able to complete the practice on time. All in all, the survey camp was a great experience filled with fun and unexpected challenges.

CHAN OiKwai (3035010963)

I belonged to Team 1 of group 2. I was responsible for the leveling and contouring of our assigned zone with my other 2 members: CHEA Man Shan Mandy and KWOK Wing Man Vivian. To improve the efficiency of our work progress, each member was assigned with one task beforehand. I was in charge of checking the reading and taking photo for reference. Mandy was the one who observed the reading and Vivian was the one who held the staff.

On the first day, our team started work after collecting the equipment. After locating our secondary vertical control points, we began doing the leveling loop. The whole work went on quite smooth and it took us about 3 hours to finish the first loop. However, after computing the data, we found that there were approximately 4 meters of error, which is far beyond the acceptable closing error. As we had not recorded the values of the upper and lower stadia, it was difficult for us to trace back the most invalid data. We decided to do the second leveling loop straight afterwards. This time, we granted an opportunity to use the digital level. The use of digital level definitely saved our time on reading the readings from the level and we spent about 2 hours to complete the loop. With the use of the digital level, the closing error of the second loop was found to be zero. Since it was about dinner time after the second leveling loophad finished, we decided to do contouring on the second day.

The second day was a rainy day. As we were afraid the weather on the third day would be even worse, we determined to start our contouring work. We used the gridding method instead of radiating line method as proposed because of 2 reasons. First, radiating line method is quite time consuming particularly in a rainy day. Second, there was an apparatus constraint that no spare theodolite was available. Since the BBQ area was quite slippery due to rain, we had 2 main considerations when we carried out our work. We needed to consider the safety of our members and the location to place the level and staff stably. Due to the poor sight in a dim, rainy environment afterwards, we were forced to stop our contouring work early (at around 5pm). We had done half of the slope area at the end of that day.

On the third day, we immediately started our work after breakfast. We finished the remaining work in the morning thanks to the fine weather. In the afternoon, our team assisted with our group members on the setting out exercise. The setting out exercise

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did not run smoothly as expected because of some bugs in the programme. What our team could help was to calculate the coordinates manually. Luckily, thanks to the efforts of our members, the bugs were finally detected and debugged. Therefore, our group could finish the setting out exercise on time.Ho Chun Yin Kelvin (3035012894)

In the memorable survey camp, I am one of the group mates of Group2 and the sub group 2 in Group 2. My group mates are Kelvin (leader), Po man and Anson. We had a mission of transverse in both the BBQ site and dormitory.

During the first day of survey camp, we were working in the upper horizontal loop. In the very beginning of our traversingmission, we were not very familiar with the equipment. Thus, the time for us for setting up the prism and totalstation takes a rather long time. Also, as our sub group had a time crash with other group in using some of the secondary control points, so we took a long time to finish the upper horizontal loop , which takes about 5 hour. Moreover, after we had arrived the area, we found some of the proposed turning points were not suitable for setting up equipment, so we limit our secondary control to eight in the upper horizontal loop. We finish the first time looping in about 1700. However, some of our control points were not recorded very precisely, so we decided to redo some of our control points.

During the second day of survey camp, as a serious raining happened, we first decided to redo some control points in the upper horizontal loop because the environment in the BBQ site was bad. After we had finished the checking of controlpoints, as the error this time within the required range, so we started the transverse in the BBQ site . However, due to the heavy rain, the progress was so slow that we only completed four control points at about three pm. Luckily, the weather was getting well after four pm , so we completed the lower horizontal loop before sunset.

During the third day of survey camp, as we have completed the whole area transverse, so we started the setting out task. Unfortunately, our setting out programme was incorrect, so we had to correct it into another programme. We finished the corrected programme after lunch, we completed the setting out task at about 1600. And then we leave the campsite about 1800.

This survey camp is unforgettable and useful. I have learned how to use varies surveying equipment and how to corporate with other group mates. Last but not least, it helps me to know the actual work environment of an professional civil engineer.

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NG Chin Him (2012521290)

In the survey camp, I am one of Group 4 members.The sub group that I belong to is detailing. In my sub group, we have 4 members including me, Mike (leader), Leo and York. Our aim is to complete the detailing part in BBQ site and dormitory area.

We had a short briefing after we reached the camp site. Then we started to check the equipment that provided and picking up our equipment straight away to the BBQ site. We did the upper part of the BBQ site and small part of the dormitory area on the first day. At start, we were not getting used to use equipment, so we took longer time to work on each turning point. The turning points that we used were recorded by the transverse team. They stick a coin on each point to notify us. Then we set the tripod base on those coins and measured objects around us. We made us of division of labour to increase our efficiency after lunch. Somebody did the observation, somebody read out the numbers from theodolite, etc. We also swap the duties, this is because we could try different kind of jobs and understood more about detailing. Just before we had dinner we had finished the small part of the dormitory area and stop working. The reason is because there were insufficient of light to read the number on staff. The number of working hour on the first day was 5 hours.

Unfortunately on the second day there was a heavy rain, but we have to finish the detailing of the rest of the area (lower part of BBQ site and major of dormitory areas). We worked on the dormitory area from morning till early afternoon. Basically we did the same thing on the first day. However after we had lunch, the theodolite does not work for some reason. Therefore we used total station instead of it. After that the progress had been raised up. At night I drew a rough map of our zones, we also discuss the work that we are going to do on the last day.

We all did the setting out task together. In the morning we were figuring out how to set up the total station and theodolite, as we could get a spare theodolite. Then we got a problem of the programmed that we prepared before, but we soft it after lunch. We finished the setting out about 4pm and we left around 6pm

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From my point of view, this is a definitely one of the highlight in my first year university life. I think it is a really chance for us to learn stuff outside of class, for example, we could learn how to cooperate and communicate with other people.

YIM YU WAI (3035010743)I was the sub-group team leader of the detailing sub-group team. Our group had 4 members in total. Initially, we had a theodolite, a staff and a tape for carrying out the detailing work.During the first day, we examined again the location we had to carry out detailing work. After traversing team successfully located their traversing points by putting the marked coins on the located they wanted, we started to carry out detailing work based on their traversing point. Since, the region we needed to carry out detailing work was a bit of large. All of us knew it would be very tough in the following days. Firstly, in the first day morning, we selected the middle part of Zone 2 (the road and the building) for detailing works. At the beginning, we were not used of the equipment and the method of measurement. There were other 2 teams waiting for using our point at that time and they urged us to carry the works as quickly as possible. Since there many floors and corners of the external wall of the building, choosing points for detailing were difficult. With being urged by other teams and not being used of the measurement method, lots of important points for detailing work in this region were missed. As the weather seemed not good, we decided to carry out detailing work at the BBQ site first in considering the safety. We spent the whole afternoon of the first day in the BBQ site. After we had measured lots of point with using the theodolite, the staff and the tape, we were used to that equipment and could carry out the measuring work in a very short time. Although we could measure very quickly, there lots of points needed to be measured; we still have not finished our detailing work at BBQ site. At that time, it was rained. Before we went to dinner, we measure the building of the middle part of the zone 2 again since there was not enough light for us to carry out detailing work in the BBQ site. During the second day morning, we carried out the detailing works at the middle part of the zone 2. A great problem was encountered during the measuring work. The theodolite got wet so that we could not use it to precisely locate the coin under it. We had reported that problem and asked for replacing the equipment. However, all theodolites had been borrowed by other teams. We had to use the total station and a pole with a prism for detailing. We spent some time for learning how to use that equipment. Since using the total station for detailing was more convenient than using the theodolite, we had done the measuring works for nearly the whole zone 2 region

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within the day2. During the night, we had examined the data we measured and checked whether there were problems in the detailing work. We found that some points were missed and some data were wrongly recorded. In this camp, we had learned lots of surveying techniques and gained experience how to cooperate with other people as well.Appendix B – Raw DataA) Traversing

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B) Leveling

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C) Contouring

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Surveying Camp Report (Zone 2)

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