ADVANCED SURVEYING

FOR THE COURSE OF

CE 406: ADVANCED SURVEYING

WORLD UNIVERSITY OF BANGLADESH DEPARTMENT OF CIVIL ENGINEERING

september2013

© This copy is written for the students of 5th semester of Dept. of civil engineering for 2 credit course of CE 406: Advanced Surveying. It is not for sell or any kind of financial profit making. All rights whatsoever in this book are strictly reserved and no portion of it may be reproduced any process for any purpose without the written permission of the owners. -----------------------------------------------------------------------------------------------------

AUTHOR S M Tanvir Faysal Alam Chowdhoury, B.Sc. (Civil)

Lecturer in Dept. of Civil Engineering

WORLD UNIVERSITY OF BANGLADESH

Written by:

MUHAMMAD MZANUR RAHMAN Student ID:2858 Students of: Batch 59D (It is a course work task) Dept. of Civil Engineering World university of bangladesh

Photogrammetry Photogrammetry: - Photogrammetry is the method of surveying in which plans

and maps are prepared from photographs taken from suitable camera stations. It is also known as photographic survey.

Purposes:- Followings are the purposes of photographic survey:-

1. Preparation of topographic maps; 2. Preparation of composite picture of the ground; 3. Acquisition of military intelligence; 4. Soil classification; 5. Interpretation of geology.

Types of photographic survey:-

1. Terrestrial ground 2. Aerial

Terrestrial photogrammetry:- Terrestrial photogrammetry denotes that

branch of photogrammetry where in maps are prepared from photographs taken from camera axis horizontal. It is a further development of plane table survey.

Elements:-

1. Phototheodolite; 2. Favorable atmosphere.

Classification of terrestrial photogrammetry:- Followings are the

classifications of the terrestrial photogrammetry. 1. Still photography:- Photographs of still object such as building is classified as still photography. 2. Quasi static photography:- Whereas a series of photographs taken in fairly rapid sequence in order to picture, the position of a slow moving object at various circumstances is termed as quasi static photography. Example: movement of a ship near a port. 3. Dynamic photography:- When measurement of an objects which changes its size, shape, position or orientation from one instant to another are made through a motion picture camera, it is termed as dynamic photography. Aerial photograph:- The photographs which are taken from camera stations in the air with the axis of the camera vertical or nearly vertical, are called aerial photographs.

Purposes of aerial photographs:-

(i) Reconnaissance and preliminary surveys; (ii) Roads & Railways; (iii) Water supply; (iv) Power schemes & transmission lines; (v) Acquisition of land; (vi) Town and village planning; (vii) Flood control, irrigation, drainage and soil conservation; (viii) Mining prospects; (ix) Study of geology; (x) Soil and agricultural studies; (xi) Military installations, camping and forbidden zones.

Classification of aerial photographs:- According to the directions of camera

axis, aerial photographs may be divided into following classes:

(i) Vertical photographs:- The photographs which are taken from the air with

the axis of the camera vertical or nearly vertical are called vertical photographs. A truly vertical photograph closely resembles a map.

(ii) Oblique photograph:- The photographs which are taken from the air with

the axis of the camera vertical or nearly vertical intentionally tilted from the vertical are called oblique photograph. It covers large area of the ground. Again oblique photographs are two types are as follows:

(a) Low oblique photograph:- An oblique photograph which does not show the

horizon, is known as low oblique photograph.

(b) High oblique photograph:- An oblique photograph which is sufficiently tilted to

show the horizon, is known as high oblique photograph.

(iii) Convergent photograph:- The low oblique photographs which are taken

with two cameras exposed simultaneously at successive exposure stations with their axis tilted at a fixed inclination from the vertical in the direction of the line of flight, so that the forward exposure of the first station from a stereo pair with the backward exposure of the next station are called convergent photograph.

(iv) Trimetrogon photograph:- This type of photograph is a combination of

vertical slow oblique photographs exposed simultaneously from the air station from two cameras.

Stereophotogrammetry:- Stereoscopy states that if two overlapping air

photographs containing the same object taken from different positions, are viewed through a stereoscope, the corresponding object will fuse and the terrain will appear in three dimensions. Stereoscopic or binocular vision is the facility which makes stereoscopy possible. The perception of depth is made possible in several ways.

Uses of Stereophotogremmetry:- There are several uses of

stereophotogrammetry which are given below:-

(i) Survey of reservoir sites; (ii) Contouring the building maps; (iii) Geological mapping of vertical faces; (iv) Archeological mapping of monument; (v) It is most economical for areas up to 25 square kilometers.

Parallax:- The term parallax is applied to the movement of the image of one

stationary object with respect to the image of another stationary object when the eye is moved side ways.

Basic principle of Terrestrial photography:

The principle of Terrestrial photography was improved upon and perfected by captain Deville, then Surveyor general of Canada in 1888. In Terrestrial photogrammetry, photographs are taken with the camera supported on the ground. The photographs are taken by means of a phototheodolite which is a combination of a camera and a theodolite. Maps are then compiled from photographs.

The principle underlying the method of Terrestrial photogrammetry is exactly similar to the plane table survey, i.e. if the directions of same objects photographed from two extremities of measured base are known, their positions can be located by the intersection of two rays to the same object. However, the difference between this and plane tabling is that more details are at once obtained from the photographs and their subsequent plotting etc. is done by the office while in plane tabling all the detailing is done in the field itself.

In the figure (given below) A and B are two stations at the ends of base AB. The arrows indicate the direction of horizontal pointing of the camera. For each pair of pictures taken from the two ends, the camera axis is kept parallel to each other. From economy and speed point of view, minimum number of photograph should be used to cover the whole area and to achieve this, it is essential to select the best positions of the camera stations. A through study of the area should be done from the existing maps, and a ground reconnaissance should be made. The selection of actual stations depends upon the size and ruggedness of the area to be surveyed. The camera should be directed downward rather than upward, and the stations should be at the higher points on the area.

Phototheodolite:- This equipment consists of the following parts and

accessories: (i) Theodolite; (ii) Camera; (iii) Tripod; (iv) Field glass; (v) Steel; (vi) Plate holder; (vii) Light meter; (viii) Field meter; (ix) Metal dark slider.

Relation between the principle point, plumb point and ISO centre of a tilted photograph.

(i) The distance of the plumb from the principle point is tf tan .

Proof: From geometry we get, prs is a right angled triangle whose;

pr =Perpendicular, rs=Base, ps =Hypotenuse,

tpsr , 90prs and rs=Focal length (f) of the lens.

We know, rs

prt tan

trspr tan ][ frs

tfpr tan (Proved)

(ii) The distance of the ISO centre from the principle point is2

tant

f .

Proof:- From geometry we get, qrs is another right angled triangle whose;

qr =Perpendicular, rs=Base, qs =Hypotenuse,

2

tqsr , 90qrs and rs=Focal length (f) of the lens.

We know, rs

qrt

2tan

2

tant

rsqr ][ frs

2

tant

fqr (Proved)

(iii) The distance of the horizontal point along the principle line from the principle point is equal to tf cot .

Proof:- From geometry we get, vsr is also another right angled triangle whose;

rs=Perpendicular, vr=Base, sv=Hypotenuse,

trvs , 90vrs and rs=Focal length (f) of the lens.

We know, rs

rvt cot

trsrv cot ][ frs

tfrv cot (Proved)

Scale of vertical Photograph:- Let, N is the perspective centre, H is the flying height of the camera, B is the top hill of height h above mean sea level (MSL), V is the ground plumb point, b is the image of the top B on the photograph, d is the plump point of the photograph, f is the focal length of the camera.

Figure:-

Construction:- Draw BK parallel to the ground and perpendicular to the NV

meeting at K. From Nbd & NKB similar triangle we get:

hH

f

NK

Nd

KB

bd

Scale of vertical photograph=hH

f

Displacement of photo image due to height:- Let, N is the camera station,

f is the focal length of the camera, h is the height of the hill above mean sea level (MSL),

H is the flying height of the camera, D is the horizontal distance of A from plump point V, Then the perspective rays from A and B will appear on the photographic plane at a & b respectively,

The Displacement (ab) to the image of point B with respect to the image of the point A is known as height displacement.

Figure:-

Construction:- Through B, draw BK perpendicular to NV meeting at K. Joint

NB and extend it up to the horizontal line VA. From similar triangle Nab & NAC we get,

H

f

NV

Nd

NA

Na

AC

ab

H

f

AC

ab

H

ACfab

……………………… (i)

From NKB & ABC similar triangle we get,

h

hH

AB

NK

AC

KB

h

hH

AC

KB

hH

KBhAC

hH

DhAC

……………………… (ii)

Substituting the value of AC in (i) we get,

hH

Dh

H

fab

)( hHH

fDhab

……………………. (iii)

Again from NKB & Nbd we get,

f

hHD

Nd

NK

db

KB

f

hHD

f

hHD

)(

……………….. (iV)

Using this value of D in (iii) we get,

)(

)(

hHH

f

hHfh

ab

)(

1)(

hHHf

hHfhab

H

hab

This is the Displacement of photo image due to height.

Photo mosaic:- A series of air vertical photograph in their relative position so

as to form map like photograph of the ground is called photo mosaics. There are two types of photo mosaics: (i) Controlled mosaics:- Mosaic which is obtain from air vertical photograph carefully assembled so that the horizontal control point agree with their relative plotted position is called controlled mosaics. (ii) Uncontrolled mosaics:- Mosaic which is plotted without any control points is called uncontrolled mosaics.

Advantages:-

(i) A photo mosaic can be compiled from available photographs more rapidly and economically with a map. (ii) Interpretation of terrain features from a mosaics may be done rapidly and accurately of details as compared than a map. (iii) A photo mosaic show details whereas a map is show only selected details.

Disadvantages:-

(i) The horizontal distances are not accurate due to unequal scale. (ii) The visualization of configuration of terrain in vertical direction from a mosaic is difficult. (iii) Due to the vegetation cover on a mosaic the important details such as mosque, temple etc are not observed.

Problem:- A vertical photograph were taken from the height of 3000m above the

terrain of 15cm. focal length. Calculate the scale of photograph.

Solution:- Given,

.3000mfH And focal length, f =15cm.

We know,

Scale of photograph=hH

f

3000

15.0

15.0

300015.0

15.0

2000

1

2000:1 Or (Ans.)

Problem:- A straight length of highway AB appears to be 12.5cm. on vertical air

photograph of 15cm, focal length. The corresponding distance of highway on a 1:50000 topographical maps is 6.25 cm. Assuming average elevation of the terrain of the terrain as 1250m. above MSL. Calculate the flying height of the camera.

Solution:- We know,

distance Map

scale Map

distance

scale

Photo

Photo

distance Map

scale Mapdistance scale

PhotoPhoto

25.6

50000

15.12

25.6

1

50000

15.12

25000

1

Scale of photograph= 25000:1

Scale of photograph=hH

f

1250

15.0

25000

1

H

37501250 H 12503750 H

.5000mH (Ans.)

Problem:-, A scale of photograph is 1cm.=100m. The size of photograph is

.2020 cmcm The longitudinal overlap is 60%, Side lap 30%, Number of photograph

to cover the area of .1010 kmkm Find the total nos. of photograph.

Solution:- Given, Length of covered area, L=10Km. Width of covered area, W=10Km. Length of picture l=20cm.0.2m.

Width of picture w=20cm.0.2m.

Longitudinal overlap, lP =60%

Side lap, wP =30%

Scale of photograph, s=1cm=100m

10000:110000

1

100100

1

100

1

cm

cmcm

m

cm

1)1( 1

1

pl

LSN

1

)100

601(

100

2010000

1100010

1

N

145.13)15.12(1 N

Similarly,

)1(

2pww

WSN

)100

301(

100

2010000

1100010

2

N

814.7)114.6(2 N

Number of photograph= 21 NN

.112814 Nos (Ans.)

Remote sensing:- Remote sensing is the acquisition of interpretation about

an object or phenomenon, without making any physical contact with the object. There are main two types of remote sensing: (i) Passive remote sensing: Passive remote sensing detect natural radiation that is emitted or reflected by the object or surrounding areas. Reflected sunlight is the most common sources of radiation measured by the passive sensors. Examples: passive remote sensors include film photography, infrared, charge-coupled devices and radiometers. (ii) Active remote sensing: emits energy in order to scan objects and areas whereupon a sensor then detects and measures the radiation that is reflected or backscattered from the target. Examples: RADAR and RIDAR are examples of active remote sensing where the time delay between emission and return is measured, establishing the location, height, speeds and direction of an object. Applications:

(i) Monitoring deforestation in area such as the Amazon Basin, glacial features in Arctic and Antarctic regions. (ii) Collection of data about dangerous border areas for military. (iii) Remote sensing also replaces costly and slow data collection on the ground. (iv) Aerial traffic control, early warning of danger. (v) Monitoring speed limits. (vi) Meteorological data collection such as wind speed and direction of wind.

Remote sensing software: Remote sensing data is processed and analyzed with computer software, known as a remote sensing application. The most used applications in remote sensing are as follows:

ERDAS ESRI GRASS GIS ILWIS QGIS OSSIM IDRISI etc.

Geographic information system(GIS)

Definition:- Geographic information system (GIS) is a system designed to capture, store, manipulate, analyze, manage and present all types of geographic data. Benefits of GIS:-

GIS benefits organizations of all sizes and in almost every industry. There is a growing awareness of the economic and strategic value of GIS. The benefits of GIS generally fall into five basic categories. Coast saving and increased efficiency, Better decision making, Improved communication, Better record keeping, Manage geographical data. GIS gives us a new way to look at the world around us with GIS. Map where things are, Map qualities, Map densities, Find what is inside, Find what is nearby, Map change.

Global positioning system (GPS):- The Global positioning system (GPS) is a

space-based satellite navigation system that provides location and time information in all weather, anywhere on or near the earth, where there is an unobstructed line of sight to four or more GPS satellites. It is maintained by the United States government and is freely accessible to anyone with a GPS server.

Basic concept of GPS:- A GPS receiver calculates its position by precisely

timing the signals sent by GPS satellites high above the earth. Each satellite continually transmits massage that include. The time is message was transmitted, Satellite position at the time of message transmission.

Application:-

While originally a military project, GPS is considered a dual-use technology, meaning it has significant military and civilian applications. Civilian uses:- Many civilian applications use one or more of GPS’s three basic components: absolute location, relative movement and time transfer. Cartography:- Both civilian and military cartographers use GPS extensively.

Cellular telephony:- Clock synchronization enables time transfer, which is critical for synchronizing its spreading codes with other base stations to facilitate inter-cell hand off and support hybrid GPS or cellular position detection for mobile emergency calls and other applications. Clock synchronization:- The accuracy of GPS time signals ( 10 Ns) is second only to the atomic clocks upon which they are based. Disaster relief or emergency services depend upon GPS for location and timing capabilities. Geotagging:- Applying location coordinates to digital objects such as photographs and other documents for purposes such as creating map over lays. GPS aircraft tracking. GPS tours:- location determines what content to display, for instance information about an approaching point of interest. Navigation:- Navigators value digitally precise velocity and orientation measurements. Surveying:- Surveyors use absolute locations to make maps and determine property boundaries. Tectonics:- GPS enables direct fault motion measurement in earthquakes. Telemetric:- GPS technology integrated with computers and mobile communications technology in automotive navigation system. Uses of GPS:- Finding geographical position, Acquiring the satellite signals,

Following a route. Mobile phone tracking:- Refers to the attaining of the current position of a mobile phone, stationary or moving. Localization may occur either via multilateration of radio signals between (server) radios towers of the network and the phone, or simply via GPS. To locate the phone using multilateration of radio signals, it must emit at least the roaming signal to contact the next nearby antenna tower, but the process does not require on active call. GSM is based on the signal strength to near by antenna masts.

Errors in surveying Definition:- By error in surveying, we mean discrepancy between the observed value and true value of any measured quantity. Error in surveying may be classified in to the following groups:

(i) Mistake, (ii) Cumulative errors, (iii) Compensating errors, (iv) True errors, (v) Residual errors, (vi) Probable errors, (vii) Constant errors, (viii) Systematic errors, (ix) Accidental errors, (x) Average errors, (xi) Standard errors, (xii) Permissible errors. Mistake:- Mistakes are errors which arise from inattention, inexperience, careless, poor judgment or confusion in mind of the observer. If this type of error is undetected, it produces a serious effect upon the final result. Example: The counting of 8 for 3. Cumulative errors:- A cumulative error makes the observed reading either too large or too small. Variation of temperature, humidity, pressure, wind, velocity, curvature and refraction etc are the causes of this type of error. Example: The faulty alignment of a line. Compensating errors:- This type of error tends to occur in both direction and thereby compensating each other. Example: Inaccuracy of chain length of the ground. True errors:- It is difference between the true and observed value of a quantity. Residual errors:- It is difference between the most probable value of quantity and its observed value. This is also known as apparent errors. Probable errors:- This is defined by saying that errors are equally likely to be numerically greater or less than the probable error. Constant errors:- It is an error which has got the same effect in all the observations. As for an example, if the tape is 0.01’ to long, it will give an error of 0.01’ in the measurement of each tape length. Systematic errors:- It is the error which occurs systematically. Due to the rise or fall of temperature, there will be expansion or contraction of the measuring appliances such as steel tape. Errors resulting from this from this are systematic.

Accidental errors:- Same as compensating errors. Permissible errors:- The permissible error is the maximum allowable limit that a measurement may vary from the true value, or from a value previously adopted as correct. Average errors:- Standard errors:-

Hydrographic surveying Hydrographic surveying:- It is a method of surveying which includes works for projects in rivers, lake, harbors, bays and costal areas. Purposes of Hydrographic surveying:- Hydrographic surveying is performed for the following purposes:

1. Measurements of discharge and quantity of water in connection with water resources schemes, power schemes, flood control and drainage projects.

2. Determination of bed depths by sounding for navigation including location sand bars, rock navigation lights, etc.

3. Location of station of river beds and any bay mouths and their dredging operations.

4. Determination of directions of currents for the location of sewer out falls areas subjected to scour and silt.

5. Preparation of contour maps under water, nautical charts.

6. Measurements of tides for marine structures in costal defence, harbors and ports. Project surveying:- Project surveying includes all field works and requisite calculations together with maps, profiles and other related drawings involved in the planning and construction of any engineering projects like railways, highways, irrigation canals, sewer lines, tunnels, dams etc. Irrigation Project:- The surveying that is conducted for the completion of an irrigation project may be classified into three different categories. They are:

(1) Preliminary survey; (2) Detail survey; (3) Construction survey.

Hydrographic Project:- A hydrographic Project includes the determination of shore lines, sounding and silting, navigable depth, velocity and characteristics of the flow of water, location of buoys light houses, sand bars, etc. Survey of shore lines:- This is executed either from a speed boat or by running a traverse along with shore first the control stations are fixed and surveyed by traversing sound the cost. Soundings:- The measurement of depth below the water surface is known as sounding. The object of sounding is to take cross-section or the longitudinal section of the water profile from the bed.

Project Survey

Mass diagram:- Mass diagram is such a diagram is presented to the predict the

proper distribution of excavated earth position borrow pits and possible location of banks along the alignment of project which may involve: Roads Railways Irrigation etc.

Problem:- A portion of thr longitudinal section is given, where the volume of

earthwork has already been calculated from the available field data. Draw the mass diagram.

Chainage (m) Cutting ( 3m ) Filling ( 3m )

0-50 +150

50-100 -120

100-150 -90 +60

150-200

200-250 -100

250-300 +80

300-350 +120

350-400 -130

Solution:-

Section Chainage (m)

Cutting

( 3m )

Filling

( 3m )

Sum cutting & filling

Net volume

( 3m )

1 0 0 0 0 0

2 50 +150 +150 +150

3 100 -120 +150 - 120 +30

4 150 -90 +30 - 90 -60

5 200 +60 -60+60 0

6 250 -100 0-100 -100

7 300 +80 -100+80 -20

8 350 +120 -20+120 +100

9 400 -130 +100-130 -30