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surveying and geomatics
- 1. R A SH M I B R A S S I S TA N T P R O F E S S O R C I V I L D E PA R T M E N T B I T S , N A R S A M P E T WA R A N G A L
- 2. Syllabus Introduction andBasic Concepts, Measurement of Distances and Directions Leveling, Contouring, Area, Volume Theodolite Surveying, Traversing Curves, Tachometric Surveying, Modern Surveying Methods Photogrammetry Surveying
- 3. Course Objectives Knowthe principle and methods of surveying. Measure horizontal and vertical- distances and angles Recording of observation accurately Perform calculations based on the observation Identification of source of errors and rectification methods Apply surveying principles to determine areas and volumes and setting out curves Use modern surveying equipment’s for accurate results
- 4. Course Outcomes Applythe knowledge to calculate angles, distances and levels Identify data collection methods and prepare field notes Understand the working principles of survey instruments, measurement errors and corrective measures Interpret survey data and compute areas and volumes, levels by different type of equipment and relate the knowledge to the modern equipment and methodologies
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- 11. Primary Division ofSurvey Survey can be divided into 2 groups Plane Survey Geodetic Survey
- 12. Primary Division ofSurvey
- 16. Principles of Surveying Thetwo fundamental principal of surveying are To work from whole to part To fix the position of new points by at least two independent processes or point
- 21. Classification of survey Classificationof survey has been done based upon Nature of the field survey Object of survey Instrument used
- 22. Classification of surveyhas been done based upon Nature of the field survey
- 23. Classification of surveyhas been done based upon Object of survey
- 24. Classification of surveyhas been done based upon Object of survey
- 25. Classification of surveyhas been done based upon Object of survey
- 26. Classification of surveyhas been done based upon Instrument used
- 27. Classification of surveyhas been done based upon Instrument used
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- 47. Shrinkage of Map In old map graphical scale is not shown Only R.F. is written Map get shrink 2 points picked and length calculated using R.F. Same points distance measured on ground Then remaining distances and areas are calculated using
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- 49. Phases of Surveying Asurvey work has the following phases 1. Planning ,Analysis & Decision making. 2. Case and adjustment of instrument. 3. Field work 4. Office work
- 50. Planning ,Analysis &Decision making It involves the following
- 51. Case and adjustmentof instrument.
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- 57. Accessories of surveying Followingaccessories are required for surveying 1. Arrows 2. Pegs 3. Ranging rod 4. Ranging poles 5. Plumb bob 6. Laths 7. Offsets rods
- 58. Measurement of Distancesand Directions Linear distances- Approximate methods- This method are used in resurvey or to detect major mistake. They give better results on smooth roads Error will be within 1 percent
- 59. Types of Approximatemethods Pacing Measured with Passometer Measured with Pedometer Measured with Odometer Measured with Speedometer
- 60. Passometer: • Itis a small instrument which counts the number of paces. Pedometer: • This instrument directly gives the distance by multiplying the number of paces with the average pace length of the person carrying the instrument.
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- 63. Odometer • An odometeris a simple device which can be attached to the wheel of a bicycle or any such vehicle. The odometer registers the number of revolution made by the wheel. The distance covered is equal to the product of the number of revolutions and the perimeter of the wheel.
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- 65. Speedometer This isused in automobile to measure the distance
- 66. Direct Methods Thedirect distance measurement in the field is done using chain or tape
- 67. Instruments Used inChaining • The following instruments are used while chaining. • Chains • Tapes • Arrows • Ranging rods and offset rods • Laths & Whites • Pegs • Plumb bob • Line Ranger
- 68. Instruments Used inChaining Chains • Various types of chains used in surveying are • Metric Chain • Gunter‟s Chain or Surveyor‟s Chain • Engineer‟s Chain • Revenue Chain • Steel Band or band chain
- 69. Metric Chain • Normallythis chain consists of galvanized mild steel wire of 4 mm diameter known as link. The ends of the links are bent into loop and connected together by means of three oval rings which provide the flexibility to the chain and make it less liable to kinking. Both ends of the chain have brass handle with swivel joint so that the chain can be turned round without twisting
- 70. • In ametric chain at every one meter interval of chain, a small brass ring is provided. Brass tallies are also provided at every 5.0 m length of chain. Each tally has different shape which indicates 5 , 10, 15m from any one side of the chain, metric chains are available in 20 m and 30 m length. • A 20 m chain has 100 links each of 20 cm and 30 m chain has 150 links. Length of chain is embossed on the brass handles of the chain.
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- 72. Günter's chain • A66 feet long chain consists of 100 links each of 0.66 ft it is known as Gunter‟s Chain • Here, 10 sq chain are equal to 1 acre, • 10 chains= 1 furlong and 8 furlongs = 1 mile • This chain is suitable for taking length in miles and areas in acres.
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- 74. Engineer’s Chain • A100 ft chain of 100 links each of 1 foot is known as Engineer’s chain. Brass tags are fastened at every 10 links. This chain is used to measure length in feet and area in square yards.
- 75. Revenue Chain • Revenuechain is 33 ft long chain consisting of 16 links. This chain is used for distance measurements in feet & inches for small areas.
- 76. Steel Band orBand Chain • Steel bands are preferred than chains because they are more accurate, but the disadvantages is that they get broken easily and are difficult to repair in the field. They are 20 and 30 m long, 12 to 16 mm wide and 0.3 to 0.6 mm thick. They are numbered at every metre and divided by brass studs at every 20 cm
- 77. Measuring Tapes • Tapesare used for more accurate measurement. The tapes are classified based on the materials of which they are made of such as: • Cloth or linen tape • Fibre Tape • Metallic Tape • Steel tape • Invar Tape
- 78. Cloth or linenTape • Linen tapes are closely woven linen and varnished to resist moisture. They are generally 10 m, 20 m, 25 m and 30 m long in length and 12 to 15 mm wide. They are generally used for offset measurements. These tapes are light and flexible.
- 79. Fibre Glass Tape •These tapes are similar to linen and plastic coated tapes but these are made of glass fibre. The tapes are quite flexible, strong and non- conductive. These can be used in the vicinity of electrical equipment. These tapes do not stretch or shrink due to changes in temperature or moisture. These tapes are available in length of 20 m, 30 m and 50 m length.
- 80. Metallic Tape • Alinen tape reinforced with brass or copper wires to prevent stretching or twisting of fibres is called a metallic tape. As the wires are interwoven and tape is varnished these wires are visible to naked eyes. This is supplied in a lather case with a winding device. Each metre length is divided into ten parts (decimetres) and each part is further sub-divided into ten parts. It is commonly used for taking offset in chain surveying.
- 81. Steel Tape • Thesteel tape is made of steel ribbon of width varying from 6 to 16 mm. The commonly available length are 10 m, 15 m, 20 m, 30 m and 50 m. It is graduated in metres, decimetres, and centimetres. Steel tapes are used for accurate measurement of distances.
- 82. Invar Tape • Invartape are made of alloy of nickel 36 % and steel 64 % having very low co-efficient of thermal expansion. These are 6 mm wide and generally available in length of 30 m, 50m, 100m. It is not affected by change of temperature therefore, it is used when high degree of precesion is required.
- 83. Ranging When asurvey line is longer than a chain length, it is necessary to align intermediate points on chain line so that the measurements are along the line. The process of locating intermediate points on survey line is known as ranging. There are two methods of ranging viz., direct ranging and reciprocal ranging.
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- 85. Direct Ranging • Ifthe first and last points are intervisible this method is possible. • Stations A and B in which an intermediate point C is to be located. Point C is selected at a distance slightly less than a chain length. At points A and B ranging rods are fixed. The assistant holds another ranging rod near C. Surveyor positions himself approximately 2 m behind station A and looking along line AB directs the assistant to move at right angles to the line AB till he aligns the ranging rod along AB. Then surveyor instructs the assistant to mark that point and stretch the chain along AC.
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- 90. Indirect or ReciprocalLeveling • Due to intervening ground, if the ranging rod at B is not visible from station A, reciprocal ranging may be resorted. Figure shows this scheme of ranging. • It needs two assistants one at point M and another at point N, where from those points both station A and station B are visible. It needs one surveyor at A and another at B. To start with M and N are approximately selected, say M1 and N1. Then surveyor near end A ranges person near M to position M2 such that AM2N1 are in a line. Then surveyor at B directs person at N, to move to N2 such that BN2M2 are in a line. The process is repeated till AMNB are in a line.
- 91. Indirect or ReciprocalLeveling
- 92. Indirect or ReciprocalLeveling
- 93. Indirect or ReciprocalLeveling
- 94. Indirect or ReciprocalLeveling
- 95. Indirect or ReciprocalLeveling
- 96. Indirect or ReciprocalLeveling
- 97. Prismatic Compass APrismatic compass is a navigation and surveying instrument which is extensively used for determining course, waypoints and direction, and for calculating bearings of survey lines and included angles between them
- 98. Bearing The bearing ofa line is the horizontal angle which it makes with a reference line(meridian). Type of bearings True Bearing Magnetic Bearing Grid Bearing Arbitrary Bearing
- 99. 1) True Bearing:The true bearing of a line is the horizontal angle between the true meridian and the survey line.The true bearing is measured from the true north in the clockwise direction. 2) Magnetic Bearing: the magnetic bearing of a line is the horizontal angle which the line makes with the magnetic north. 3) Grid Bearing: The grid bearing of a line is the horizontal angle which the line makes with the grid meridian. 4) Arbitrary Bearing: The arbitrary baring of a line is the horizontal angle which the line makes with the arbitrary meridian.
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- 101. • Magnetic meridian:- The direction shown by a freely suspended needle which is magnetized and balanced properly without influenced by other factors is known as magnetic meridian • True meridian :- True meridian is the line which passage through the true north and south. The true meridian at any point can be determinate by either observing the bearing of the sun at 12 noon or by sun’s shadow. • Arbitrary meridian :- In case of small work or in places were true meridian or magnetic meridian cannot be determined, then any direction of prominent object is taken as a reference direction called as arbitrary meridian.
- 105. The bearing aredesignated in the following two system:- 1) Whole Circle Bearing System.(W.C.B) 2) Quadrantal Bearing System.(Q.B) Measurement of Bearings :
- 106. •The bearing ofa line measured with respect to magnetic meridian in clockwise direction is called magnetic bearing and its value varies between 0ᴼ to 360ᴼ. •The quadrant start from north an progress in a clockwise direction as the first quadrant is 0ᴼ to 90ᴼ in clockwise direction , 2nd 90ᴼ to 180ᴼ , 3rd 180ᴼ to 270ᴼ, and up to 360ᴼ is 4th one. Quadrantal bearing system(Q.B.) •In this system, the bearing of survey lines are measured wrt to north line or south line which ever is the nearest to the given survey line and either in clockwise direction or in anti clockwise direction Whole Circle Bearing System.(W.C.B)
- 107. • When thewhole circle bearing is converted into Quadrantal bearing , it is termed as “REDUCED BEARING”. Thus , the reduced bearing is similar to the Quadrantal bearing. •Its values lies between 0ᴼ to 90ᴼ, but the quadrant should be mentioned for proper designation. Reduced bearing (R.B) W.C.B OF ANY LINE QUADRANT IN WHICH IT LIES RULES FOR CONVERSION QUADRANT 0 TO 90 I RB=WCB N-E 90 TO 180 II RB=180-WCB S-E 180 TO 270 III RB =WCB-180ᴼ S-W 270 TO 360 IV RB=360ᴼ - WCB N-W
- 110. Fore bearing andBack bearing The bearing of a line measured in the forward direction of the survey lines is called the ‘fore bearing’(F.B.) of that line. The bearing of a line measured in direction backward to the direction of the progress of survey is called the ‘back bearing’(B.B.) of the line.
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- 121. Assignment 1. Define surveying.What is geodetic surveying? 2. write a short notes on A) ranging rod B) metric chain C) plumb bob 3. the following are observed fore bearing of the line PQ 170º 12', AB N80º 22' W, MN 350º 18' RS 210º 56' find the back bearing 4. the following interior angles are measured with a sextant in a closed traverse. The bearing of the line AB was measured as 65 with PC calculate the bearing of all lines if angle A = 135º 10' angle B = 93º 8' angle C =59º 22' angle D =72º 20' 5. convert the following quadrantle bearing into whole circle bearing system N 30º 30'E, S72º 42'E, S46º 35'W, N60º 59'E, N85º 30'W 6. explain quadrantle bearing system with example 7. define fore bearing and arbitrary meridian 8. list different kinds of chain commonly used in surveying state the advantages of each