This document discusses the use of a theodolite for surveying. It begins by explaining that a theodolite is needed to precisely measure horizontal and vertical angles, unlike a compass. It then defines theodolite surveying as surveying that measures angles using a theodolite. The document goes on to classify theodolites based on their horizontal axis and method of reading angles. It describes the basic parts of a transit vernier theodolite and explains terms used in manipulating one. Finally, it discusses methods for measuring horizontal angles, including the general, repetition, and reiteration methods.
The document discusses theodolite traversing and defines key terms related to using a transit theodolite. It describes the main components of a transit theodolite including the telescope, vertical circle, plate bubbles, tribrach, and foot screws. It explains how to perform temporary adjustments like centering the theodolite over a station mark and leveling it using the tripod and foot screws. It also provides details on measuring horizontal and vertical angles with a vernier theodolite.
This document discusses the use of a theodolite for surveying. It begins by explaining that a theodolite is needed to precisely measure horizontal and vertical angles, unlike a compass. It then defines theodolite surveying as surveying that measures angles using a theodolite. The document goes on to classify theodolites based on their horizontal axis and method of angle measurement. It describes the basic parts of a transit vernier theodolite and explains terms used in manipulating one. Finally, it discusses methods for measuring horizontal angles, including the general, repetition, and reiteration methods.
This document provides instructions for using a digital theodolite to take horizontal and vertical angle measurements of reference points by following several steps:
1) Setting up the tripod and centering the theodolite over a reference mark.
2) Leveling the theodolite using circular and plate levels to precisely align it.
3) Taking multiple rounds of horizontal and vertical angle measurements in both face-left and face-right positions to reference points, and calculating the mean values.
4) Packing up the theodolite by reversing the setup steps.
The document provides information about theodolites. It begins with an introduction stating that a theodolite is used to measure horizontal and vertical angles more precisely than a magnetic compass. It then discusses the main parts of a theodolite including the horizontal circle, vertical circle, telescope, and levels. The document also covers the history of theodolites from their early origins to modern electronic versions. It describes how to operate a transit vernier theodolite including terms like centering, transiting, swinging the telescope, and changing face. Finally, it discusses the permanent and temporary adjustments needed to ensure accurate theodolite measurements.
Tacheometric surveying is a method of surveying that determines horizontal and vertical distances optically rather than through direct measurement with a tape or chain. It uses an instrument called a tacheometer fitted with a stadia diaphragm to rapidly measure distances. The key principles are that the ratio of perpendicular to base is constant in similar triangles, allowing horizontal distance and elevation to be calculated from observed angles and staff intercept readings. Common tacheometric systems include fixed hair stadia, subtense stadia, and tangential methods. Distance and elevation formulas are derived for horizontal, inclined, and depressed line of sights depending on staff orientation. Tacheometric surveying is well-suited for difficult terrain where direct measurement is challenging
Levelling, terms related to levelling, methods of levellingMir Zafarullah
Levelling is the branch of surveying that deals with determining elevations and measuring vertical distances. It is important for engineering projects to establish accurate networks of heights. The key principle is obtaining a horizontal line of sight to measure vertical distances of points above or below this line. Common equipment includes dumpy levels, automatic levels, and digital levels. Levelling staffs are used to take readings and determine reduced levels of points. There are different types of levelling operations depending on the project needs.
The document defines levelling as determining the relative heights of points. It discusses the principle of obtaining a horizontal line of sight and objectives of finding point elevations and establishing points at required elevations. Different types of levels, staffs, benchmarks, and adjustments are described. Various levelling classifications are defined including simple, differential, profile, check, reciprocal and precise levelling. The key principle of levelling is to obtain a horizontal line of sight to measure staff readings and determine reduced levels of points.
Surveying is an important part of Civil engineering. Various part like theodolite, plane table surveying, computation of area and volume are useful for all university examination and other competitive examination
The document discusses theodolite traversing and defines key terms related to using a transit theodolite. It describes the main components of a transit theodolite including the telescope, vertical circle, plate bubbles, tribrach, and foot screws. It explains how to perform temporary adjustments like centering the theodolite over a station mark and leveling it using the tripod and foot screws. It also provides details on measuring horizontal and vertical angles with a vernier theodolite.
This document discusses the use of a theodolite for surveying. It begins by explaining that a theodolite is needed to precisely measure horizontal and vertical angles, unlike a compass. It then defines theodolite surveying as surveying that measures angles using a theodolite. The document goes on to classify theodolites based on their horizontal axis and method of angle measurement. It describes the basic parts of a transit vernier theodolite and explains terms used in manipulating one. Finally, it discusses methods for measuring horizontal angles, including the general, repetition, and reiteration methods.
This document provides instructions for using a digital theodolite to take horizontal and vertical angle measurements of reference points by following several steps:
1) Setting up the tripod and centering the theodolite over a reference mark.
2) Leveling the theodolite using circular and plate levels to precisely align it.
3) Taking multiple rounds of horizontal and vertical angle measurements in both face-left and face-right positions to reference points, and calculating the mean values.
4) Packing up the theodolite by reversing the setup steps.
The document provides information about theodolites. It begins with an introduction stating that a theodolite is used to measure horizontal and vertical angles more precisely than a magnetic compass. It then discusses the main parts of a theodolite including the horizontal circle, vertical circle, telescope, and levels. The document also covers the history of theodolites from their early origins to modern electronic versions. It describes how to operate a transit vernier theodolite including terms like centering, transiting, swinging the telescope, and changing face. Finally, it discusses the permanent and temporary adjustments needed to ensure accurate theodolite measurements.
Tacheometric surveying is a method of surveying that determines horizontal and vertical distances optically rather than through direct measurement with a tape or chain. It uses an instrument called a tacheometer fitted with a stadia diaphragm to rapidly measure distances. The key principles are that the ratio of perpendicular to base is constant in similar triangles, allowing horizontal distance and elevation to be calculated from observed angles and staff intercept readings. Common tacheometric systems include fixed hair stadia, subtense stadia, and tangential methods. Distance and elevation formulas are derived for horizontal, inclined, and depressed line of sights depending on staff orientation. Tacheometric surveying is well-suited for difficult terrain where direct measurement is challenging
Levelling, terms related to levelling, methods of levellingMir Zafarullah
Levelling is the branch of surveying that deals with determining elevations and measuring vertical distances. It is important for engineering projects to establish accurate networks of heights. The key principle is obtaining a horizontal line of sight to measure vertical distances of points above or below this line. Common equipment includes dumpy levels, automatic levels, and digital levels. Levelling staffs are used to take readings and determine reduced levels of points. There are different types of levelling operations depending on the project needs.
The document defines levelling as determining the relative heights of points. It discusses the principle of obtaining a horizontal line of sight and objectives of finding point elevations and establishing points at required elevations. Different types of levels, staffs, benchmarks, and adjustments are described. Various levelling classifications are defined including simple, differential, profile, check, reciprocal and precise levelling. The key principle of levelling is to obtain a horizontal line of sight to measure staff readings and determine reduced levels of points.
Surveying is an important part of Civil engineering. Various part like theodolite, plane table surveying, computation of area and volume are useful for all university examination and other competitive examination
This document describes three methods for measuring horizontal angles with a theodolite:
1) Ordinary Method: A horizontal angle is measured between points A and B by sighting each point and recording the vernier readings. The process is repeated by changing instrument faces and the average of readings gives the angle.
2) Repetition Method: A more accurate method where the angle is mechanically added several times by repeatedly sighting point A after sighting B.
3) Reiteration Method: Several angles are measured successively at a station, closing the horizon by resighting the initial point. Any error is distributed among the measured angles.
1. The document provides information on theodolite traversing and describes the parts and functions of a transit vernier theodolite. It discusses how to set up the theodolite over a station and level it up, which are important temporary adjustments.
2. The theodolite is used to measure horizontal and vertical angles precisely and for various surveying applications. It has parts like the telescope, vertical circle, standards, and upper and lower plates.
3. Proper temporary adjustments of the theodolite include setting it up over a station point using a plumb bob, and then leveling the instrument using plate levels and levelling screws.
Introduction, classification of curves, Elements of a simple circular, designation of curve, methods of setting out a simple circular curve, elements of a compound and reverse curves, transition curve, types of transition curves, combined curve, types of vertical curves
This document discusses methods for measuring horizontal distances in chain surveying. It describes direct measurement using tapes, chains, and EDM instruments. Common sources of error in tape measurements include temperature fluctuations, sag, tension applied, and incorrect standardized length. Corrections are made to account for these errors. Perpendicular and oblique offsets from chain lines to features are also measured. Instruments like open cross staffs, adjustable cross staffs, and optical/prism squares are used to lay out right angles when measuring offsets. Proper procedures are outlined for collecting distance and offset measurements in the field.
1) Curves are gradual bends provided in transportation infrastructure like roads, railways and canals to allow for a smooth change in direction or grade.
2) There are two main types of curves - horizontal curves which provide a gradual change in direction, and vertical curves which provide a gradual change in grade.
3) Curves are needed to safely guide vehicles and traffic when changing directions or grades, to improve visibility, and to prevent erosion of canal banks from water pressure.
This document provides information about tacheometry, which is a method of surveying that determines horizontal and vertical distances from instrumental observations. It discusses how tacheometry can be used when obstacles make traditional surveying difficult. The key aspects covered include:
- Defining tacheometry and the measurements it provides
- When tacheometry is advantageous over other surveying methods
- The instruments used, including tacheometers and levelling rods
- How horizontal and vertical distances are calculated using constants
- The different types of tacheometer diaphragms and telescopes
- The fixed hair method for taking readings
This document describes different methods of trigonometric leveling to determine the elevation of points. Trigonometric leveling uses vertical angles measured with a theodolite and distances to calculate elevations. There are methods to determine elevations when the base is accessible and inaccessible, and when instrument stations and objects are in the same or different vertical planes. Calculations use trigonometric functions and relationships between angles and distances in triangles formed by the instrument stations and object.
The theodolite is an instrument used to measure horizontal and vertical angles that is more precise than a magnetic compass. It can measure angles to an accuracy of 10-20 seconds whereas a compass is only accurate to 30 minutes. The theodolite is used to measure horizontal and vertical angles when objects are at a distance or elevation where more precise measurements are needed. The method of surveying that uses a theodolite to measure angles is called theodolite surveying. The theodolite can be used to measure angles, bearings, distances, elevations, set out curves, and for mapping and construction applications.
Tacheometric surveying uses a tacheometer to determine horizontal and vertical distances through angular measurements. A tacheometer is a theodolite fitted with stadia hairs and an anallatic lens. The tacheometric formula relates the staff intercept, focal length, stadia interval and additive constant to calculate horizontal distances. Methods include stadia, fixed/movable hair, and non-stadia techniques. Determining the tacheometer constant involves measuring distances and staff intervals at stations to solve equations. Errors arise from incorrect stadia intervals or graduations. Tacheometric surveying provides distances in rough terrain but with less precision than other methods.
This document summarizes methods for setting out simple circular curves based on linear and angular methods. The linear methods discussed are by offsets from the long chord, successive bisection of arcs, offsets from tangents, and offsets from chords produced. The angular methods discussed are Rankine's method of tangential angles, the two theodolite method, and the tacheometric method. Each method is briefly described in one or two sentences.
1. Levelling is used to determine relative heights and elevations of points and establish points at required elevations. It involves using instruments like levels and staffs.
2. There are different types of levels (dumpy, tilting, wye, automatic) and staffs (self-reading, target). Precise levelling is done to establish permanent benchmarks.
3. Adjustments must be made to level instruments during setup and permanently. Methods like differential, profile and cross levelling are used depending on the task. Reciprocal levelling involves backsight-foresight exchange to check for errors.
1) Levelling is the process of determining the relative elevations of points on or near the earth's surface. It is important for engineering projects to determine elevations along alignments.
2) Levelling is used to prepare contour maps, determine altitudes, and create longitudinal and cross sections needed for projects.
3) Key terms include bench mark, datum, reduced level, line of collimation, and height of instrument. Different types of levelling include simple, differential, fly, longitudinal, and cross-sectional levelling.
The document provides information about theodolite surveying including:
1. A theodolite is an instrument used to measure horizontal and vertical angles which can also be used to prolong lines, measure distances indirectly, and for leveling.
2. Theodolite traversing involves establishing control points by measuring angles and distances between traverse stations to calculate positions.
3. Components of a theodolite include a telescope that can rotate vertically and a compass to determine direction, along with accessories like a tripod, rods, and tapes used in surveying.
This document discusses various topics related to surveying including: the objectives and processes involved in surveying like decision making, fieldwork, data processing, mapping, and stakeout; different types of surveys like plane, geodetic, topographic, route, hydrographic, land, and military surveys; instruments used like theodolites, tacheometers, planes tables, and compasses; and concepts like bearings, meridians, and reducing bearings. The key aspects covered are the goal of producing maps, the consideration or disregard of earth's curvature depending on survey type, and classification based on area, instruments, or purpose.
Levelling is a surveying technique used to determine relative elevations of points above or below a datum. The principle is to obtain a horizontal line of sight and measure vertical distances of points from this line. The objective is to find the elevation of given points with respect to an assumed reference line called the datum. Common types of levelling include differential, fly, profile, precise, check, reciprocal, trigonometric, barometric and stadia levelling. Errors in levelling can be due to personal or instrumental factors. Levelling has various uses including preparing contour maps, determining altitudes, and preparing layouts for water distribution and engineering projects.
The document discusses different types of traverses and methods for conducting traverse surveys. It describes two types of traverses: open traverses that begin and end at points of known and unknown positions, and closed traverses that begin and end at points of known positions, including closed-loop traverses that begin and end at the same point. It also outlines four methods for determining directions during traversing: chain angle method, free needle method, fast needle method, and measuring angles between lines. Finally, it discusses instruments used for measuring angles like compasses and theodolites, and defines different types of bearings including true, magnetic, and arbitrary bearings.
This document discusses the topic of chain surveying for a civil engineering class project. It provides definitions of chain surveying, noting that it involves measuring linear distances between survey stations to divide an area into triangles without taking angular measurements. It then outlines the key principles and terms of chain surveying, such as defining main stations, subsidiary stations, tie stations, main survey lines, base lines, check lines, and tie lines. Finally, it provides the basic procedures for conducting a chain survey between two stations.
This document provides an overview of surveying and leveling. It defines surveying as determining the relative positions of points on Earth through direct or indirect measurements. The main objectives of surveying are preparing maps and plans. Leveling is defined as determining relative heights or elevations of points through direct measurement of vertical distances from a reference level. Common instruments used for leveling include a level, tripod, staff, tape, and pegs. Leveling follows the principle of obtaining a horizontal line of sight to measure vertical distances of points above or below this line. Key leveling terms defined include bench mark, height of instrument, backsight, foresight, and change point. Methods for recording level data in a field book are also
The document discusses theodolite surveying and the use of a theodolite to measure horizontal and vertical angles more precisely than a compass. It defines theodolite surveying as surveying that measures angles using a theodolite. It also describes the basic parts and functions of a transit vernier theodolite, how to manipulate it, adjustments that need to be made, and methods for measuring horizontal angles.
Unit No 2 Theodolite Surveying and Traversing.pptxADCET, Ashta
1. The document discusses theodolite surveying, which is a method of surveying that uses a theodolite to measure horizontal and vertical angles.
2. A theodolite can be classified based on its horizontal axis as either a transit or non-transit theodolite, and based on how it reads angles as a vernier, micrometer, or electronic digital theodolite.
3. Common steps in using a transit vernier theodolite include setting it up over a station point, leveling it, and measuring horizontal and vertical angles through methods such as general, repetition, and reiteration.
This document describes three methods for measuring horizontal angles with a theodolite:
1) Ordinary Method: A horizontal angle is measured between points A and B by sighting each point and recording the vernier readings. The process is repeated by changing instrument faces and the average of readings gives the angle.
2) Repetition Method: A more accurate method where the angle is mechanically added several times by repeatedly sighting point A after sighting B.
3) Reiteration Method: Several angles are measured successively at a station, closing the horizon by resighting the initial point. Any error is distributed among the measured angles.
1. The document provides information on theodolite traversing and describes the parts and functions of a transit vernier theodolite. It discusses how to set up the theodolite over a station and level it up, which are important temporary adjustments.
2. The theodolite is used to measure horizontal and vertical angles precisely and for various surveying applications. It has parts like the telescope, vertical circle, standards, and upper and lower plates.
3. Proper temporary adjustments of the theodolite include setting it up over a station point using a plumb bob, and then leveling the instrument using plate levels and levelling screws.
Introduction, classification of curves, Elements of a simple circular, designation of curve, methods of setting out a simple circular curve, elements of a compound and reverse curves, transition curve, types of transition curves, combined curve, types of vertical curves
This document discusses methods for measuring horizontal distances in chain surveying. It describes direct measurement using tapes, chains, and EDM instruments. Common sources of error in tape measurements include temperature fluctuations, sag, tension applied, and incorrect standardized length. Corrections are made to account for these errors. Perpendicular and oblique offsets from chain lines to features are also measured. Instruments like open cross staffs, adjustable cross staffs, and optical/prism squares are used to lay out right angles when measuring offsets. Proper procedures are outlined for collecting distance and offset measurements in the field.
1) Curves are gradual bends provided in transportation infrastructure like roads, railways and canals to allow for a smooth change in direction or grade.
2) There are two main types of curves - horizontal curves which provide a gradual change in direction, and vertical curves which provide a gradual change in grade.
3) Curves are needed to safely guide vehicles and traffic when changing directions or grades, to improve visibility, and to prevent erosion of canal banks from water pressure.
This document provides information about tacheometry, which is a method of surveying that determines horizontal and vertical distances from instrumental observations. It discusses how tacheometry can be used when obstacles make traditional surveying difficult. The key aspects covered include:
- Defining tacheometry and the measurements it provides
- When tacheometry is advantageous over other surveying methods
- The instruments used, including tacheometers and levelling rods
- How horizontal and vertical distances are calculated using constants
- The different types of tacheometer diaphragms and telescopes
- The fixed hair method for taking readings
This document describes different methods of trigonometric leveling to determine the elevation of points. Trigonometric leveling uses vertical angles measured with a theodolite and distances to calculate elevations. There are methods to determine elevations when the base is accessible and inaccessible, and when instrument stations and objects are in the same or different vertical planes. Calculations use trigonometric functions and relationships between angles and distances in triangles formed by the instrument stations and object.
The theodolite is an instrument used to measure horizontal and vertical angles that is more precise than a magnetic compass. It can measure angles to an accuracy of 10-20 seconds whereas a compass is only accurate to 30 minutes. The theodolite is used to measure horizontal and vertical angles when objects are at a distance or elevation where more precise measurements are needed. The method of surveying that uses a theodolite to measure angles is called theodolite surveying. The theodolite can be used to measure angles, bearings, distances, elevations, set out curves, and for mapping and construction applications.
Tacheometric surveying uses a tacheometer to determine horizontal and vertical distances through angular measurements. A tacheometer is a theodolite fitted with stadia hairs and an anallatic lens. The tacheometric formula relates the staff intercept, focal length, stadia interval and additive constant to calculate horizontal distances. Methods include stadia, fixed/movable hair, and non-stadia techniques. Determining the tacheometer constant involves measuring distances and staff intervals at stations to solve equations. Errors arise from incorrect stadia intervals or graduations. Tacheometric surveying provides distances in rough terrain but with less precision than other methods.
This document summarizes methods for setting out simple circular curves based on linear and angular methods. The linear methods discussed are by offsets from the long chord, successive bisection of arcs, offsets from tangents, and offsets from chords produced. The angular methods discussed are Rankine's method of tangential angles, the two theodolite method, and the tacheometric method. Each method is briefly described in one or two sentences.
1. Levelling is used to determine relative heights and elevations of points and establish points at required elevations. It involves using instruments like levels and staffs.
2. There are different types of levels (dumpy, tilting, wye, automatic) and staffs (self-reading, target). Precise levelling is done to establish permanent benchmarks.
3. Adjustments must be made to level instruments during setup and permanently. Methods like differential, profile and cross levelling are used depending on the task. Reciprocal levelling involves backsight-foresight exchange to check for errors.
1) Levelling is the process of determining the relative elevations of points on or near the earth's surface. It is important for engineering projects to determine elevations along alignments.
2) Levelling is used to prepare contour maps, determine altitudes, and create longitudinal and cross sections needed for projects.
3) Key terms include bench mark, datum, reduced level, line of collimation, and height of instrument. Different types of levelling include simple, differential, fly, longitudinal, and cross-sectional levelling.
The document provides information about theodolite surveying including:
1. A theodolite is an instrument used to measure horizontal and vertical angles which can also be used to prolong lines, measure distances indirectly, and for leveling.
2. Theodolite traversing involves establishing control points by measuring angles and distances between traverse stations to calculate positions.
3. Components of a theodolite include a telescope that can rotate vertically and a compass to determine direction, along with accessories like a tripod, rods, and tapes used in surveying.
This document discusses various topics related to surveying including: the objectives and processes involved in surveying like decision making, fieldwork, data processing, mapping, and stakeout; different types of surveys like plane, geodetic, topographic, route, hydrographic, land, and military surveys; instruments used like theodolites, tacheometers, planes tables, and compasses; and concepts like bearings, meridians, and reducing bearings. The key aspects covered are the goal of producing maps, the consideration or disregard of earth's curvature depending on survey type, and classification based on area, instruments, or purpose.
Levelling is a surveying technique used to determine relative elevations of points above or below a datum. The principle is to obtain a horizontal line of sight and measure vertical distances of points from this line. The objective is to find the elevation of given points with respect to an assumed reference line called the datum. Common types of levelling include differential, fly, profile, precise, check, reciprocal, trigonometric, barometric and stadia levelling. Errors in levelling can be due to personal or instrumental factors. Levelling has various uses including preparing contour maps, determining altitudes, and preparing layouts for water distribution and engineering projects.
The document discusses different types of traverses and methods for conducting traverse surveys. It describes two types of traverses: open traverses that begin and end at points of known and unknown positions, and closed traverses that begin and end at points of known positions, including closed-loop traverses that begin and end at the same point. It also outlines four methods for determining directions during traversing: chain angle method, free needle method, fast needle method, and measuring angles between lines. Finally, it discusses instruments used for measuring angles like compasses and theodolites, and defines different types of bearings including true, magnetic, and arbitrary bearings.
This document discusses the topic of chain surveying for a civil engineering class project. It provides definitions of chain surveying, noting that it involves measuring linear distances between survey stations to divide an area into triangles without taking angular measurements. It then outlines the key principles and terms of chain surveying, such as defining main stations, subsidiary stations, tie stations, main survey lines, base lines, check lines, and tie lines. Finally, it provides the basic procedures for conducting a chain survey between two stations.
This document provides an overview of surveying and leveling. It defines surveying as determining the relative positions of points on Earth through direct or indirect measurements. The main objectives of surveying are preparing maps and plans. Leveling is defined as determining relative heights or elevations of points through direct measurement of vertical distances from a reference level. Common instruments used for leveling include a level, tripod, staff, tape, and pegs. Leveling follows the principle of obtaining a horizontal line of sight to measure vertical distances of points above or below this line. Key leveling terms defined include bench mark, height of instrument, backsight, foresight, and change point. Methods for recording level data in a field book are also
The document discusses theodolite surveying and the use of a theodolite to measure horizontal and vertical angles more precisely than a compass. It defines theodolite surveying as surveying that measures angles using a theodolite. It also describes the basic parts and functions of a transit vernier theodolite, how to manipulate it, adjustments that need to be made, and methods for measuring horizontal angles.
Unit No 2 Theodolite Surveying and Traversing.pptxADCET, Ashta
1. The document discusses theodolite surveying, which is a method of surveying that uses a theodolite to measure horizontal and vertical angles.
2. A theodolite can be classified based on its horizontal axis as either a transit or non-transit theodolite, and based on how it reads angles as a vernier, micrometer, or electronic digital theodolite.
3. Common steps in using a transit vernier theodolite include setting it up over a station point, leveling it, and measuring horizontal and vertical angles through methods such as general, repetition, and reiteration.
The document discusses theodolite surveying. It explains that a theodolite is used to measure horizontal and vertical angles more precisely than a compass when objects are at a distance or elevation. The theodolite surveying system involves measuring angles with a theodolite. A theodolite is the most accurate surveying instrument and is used to measure angles, locate points, prolong lines, find differences in level, set out grades, and more. The document also describes how to measure horizontal angles using the ordinary method with a theodolite.
This document provides an introduction to theodolite traversing and surveying. It defines a theodolite as a telescopic instrument used to measure horizontal and vertical angles with high precision. It describes the main types of theodolites as transit and non-transit theodolites, as well as vernier and micrometer theodolites. The document also defines various surveying terms related to theodolites and their use such as centering, transiting, face left/right, and line of collimation. Finally, it outlines the basic process for temporarily adjusting a theodolite in the field, including leveling, centering, and focusing the telescope.
The document provides information about lectures on surveying topics including:
- Classification of theodolites as transit, non-transit, vernier, and micrometer theodolites.
- Uses of theodolites for measuring horizontal and vertical angles, locating points, and other surveying tasks.
- Terms used in manipulating a transit vernier theodolite such as centering, transiting, swinging the telescope, and changing face.
- Bearings and the rules for converting whole circle bearings to quadrantal/reduced bearings.
- Definitions of open and closed traverses and the formula to check the interior angles of a closed traverse.
- An example problem on calculating
Mass diagram and its characeristics .pptNITINSURESH30
The document discusses the use of a theodolite for surveying. It describes the main parts of a theodolite including the levelling head, horizontal and vertical circles, telescope, plate levels, and clamps. It also defines important terms used when manipulating a transit vernier theodolite such as centering, transiting, swinging the telescope, and changing face. The theodolite is used to measure horizontal and vertical angles which is important for tasks like setting out grades, locating points, and tacheometric surveying.
The document discusses various surveying techniques including trigonometric leveling, tacheometry, aerial photogrammetry, and curve surveying. It provides definitions and procedures for measuring horizontal and vertical angles using a theodolite. It also describes adjusting theodolites, focusing the eyepiece, and leveling the instrument. Tacheometry is introduced as a method to determine horizontal and vertical distances through angular observations. Applications of aerial photography for engineering projects are outlined. Finally, it covers setting out simple and compound curves, as well as transition curves.
Introduction About Theodolite Instrument Theoretical part Bahzad5
Plane and Applied Surveying -2
Theodolite Theoretical part -1
Prepared by
Asst. Prof. Salar K. Hussein
Asst. Lecturer Mr. Kamal Yaseen
Overview
v Introduction About Theodolite Instrument
v Theodolite and its classification
v Parts of Theodolite
v Theodolite Axis and conditions
v Setting up the Theodolite
v Levelling & Centring - the Theodolite
v Readings in the Theodolite
v Theodolite – Instrument Checks
v Sources of errors
Erbil Polytechnic University
Technical Engineering College
Civil Engineering Department
The document provides information about the basics of using a theodolite for angle measurements in surveying. It defines key terms like angle, vertex, and degrees. It describes the main components of a theodolite including the telescope, horizontal and vertical axes, plate bubbles, and screws. It explains how to perform temporary adjustments and measure both horizontal and vertical angles using methods like ordinary, repetition, and reiteration. Precise angle measurements are important for surveying applications like setting grades, ranging curves, and tachometric surveys.
The document discusses angle measurement using transits, theodolites, and total stations. It provides definitions of horizontal, vertical, and zenith angles. It describes the basic components and functions of transits and theodolites, including different types like repeating theodolites. The document outlines procedures for measuring horizontal and vertical angles, including methods of repetition and reiteration. It also discusses instrumental errors and how to perform temporary and permanent adjustments of a theodolite.
This document provides instructions for experiments in surveying lab II, including measurement of horizontal angles using repetition and reiteration methods, trigonometric leveling to determine heights and distances, tacheometric surveying, curve setting using offset methods, and use of a total station for area determination and remote height measurement. The document includes objectives, equipment used, procedures, formulas and expected record keeping/marking for each experiment.
The theodolite is a precise instrument used to measure horizontal and vertical angles. It has greater accuracy than a magnetic compass, able to measure angles to within 10-20 seconds. The main components are a horizontal circle to measure horizontal angles, a telescope that can rotate vertically and horizontally, and spirit levels. Measurements involve setting the instrument over points and using the horizontal and vertical circles to measure angles to other points using techniques like repetition or reiteration. The theodolite is used for tasks like traversing, measuring deflection angles, and computing latitude and departure distances.
this is a surveying practicals work book in which different practicals are described with tables and graphs which are performed during a course of bachelors of civil engineering
The document discusses digital theodolites, which are optical survey instruments used to measure horizontal and vertical angles. It describes the fundamental axes of a theodolite including the vertical axis, horizontal axis, and line of collimation. Technical terms like centering, transiting, and swinging are also defined. The components of a theodolite including its telescope, eyepiece, objective lens, and threaded base are outlined. Applications like navigation, surveying, and building alignment are listed. Temporary adjustment procedures for setting up, centering, leveling, and focusing a theodolite are summarized.
The document discusses theodolite surveying. It defines theodolite surveying as surveying that measures angles using a theodolite instrument. It describes the main components of a theodolite including the trivet, lower plate, upper plate, telescope, and vertical and horizontal circles. It explains the different types of theodolites based on their method of measuring angles, such as vernier theodolites and micrometer theodolites. It also outlines the common uses and procedures for taking measurements with a theodolite.
This document provides information about the theodolite including its main parts, how to measure horizontal and vertical angles, methods for traversing, and how to compute latitudes and departures. It discusses sources of errors in theodolite measurements and how to balance a traverse using Bowditch's rule. It also includes an example problem to calculate latitudes, departures, and closing error for a given traverse and adjust it.
This document discusses theodolite surveying. It defines a theodolite as an instrument used to accurately measure horizontal and vertical angles. The document outlines the components of a theodolite and different types including transit, non-transit, vernier, micrometer, digital/electronic, and optic theodolites. It also defines various technical terms used in theodolite surveying such as swinging, transiting, face left, face right, and changing face. The main uses and functions of a theodolite are to measure horizontal and vertical angles, magnetic bearings, deflection angles, horizontal distances, and elevations.
The document describes a field experiment to measure a base line using manual surveying methods. It provides details on the equipment used, including a theodolite, auto level, thermometer, spring balance, supporting stands, pegs, steel tape, fiber glass tape and leveling staff. It also gives the objectives and relevant theory on base lines and how to measure them accurately using corrections for temperature, pull on the tape, and other factors. The goal is to find the length of the base line with complete accuracy by applying all necessary corrections.
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An In-Depth Exploration of Natural Language Processing: Evolution, Applicatio...DharmaBanothu
Natural language processing (NLP) has
recently garnered significant interest for the
computational representation and analysis of human
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contemporary trends, and challenges. Finally, we
discuss some available datasets, models, and
evaluation metrics in NLP.
2. THEODOLITE SURVEYING
INTRODUCTION:
So far we have been measuring
horizontal angles by using a Compass with respect to
meridian, which is less accurate and also it is not
possible to measure vertical angles with a Compass.
So when the objects are at a considerable
distance or situated at a considerable elevation or
depression ,it becomes necessary to measure horizontal
and vertical angles more precisely. So these
measurements are taken by an instrument known as a
theodolite.
2
4. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
CLASSIFICATION OF THEODOLITES
Theodolites may be classified as ;
A.BASE ON HORIZONTAL AXIS
i) Transit Theodolite.
ii) Non Transit Theodolite.
B.BASE ON ANGEL
i) Vernier Theodolites.
ii) Micrometer Theodolites.
iii)Electronic digital theodolite.
8
5. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
CLASSIFICATION OF THEODOLITES
A. Transit Theodolite: A theodolite is called a transit
theodolite when its telescope can be transited i.e
revolved through a complete revolution about its
horizontal axis in the vertical plane, whereas in a-
Non-Transit type, the telescope cannot be
transited. They are inferior in utility and have now
become obsolete.
9
6. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
CLASSIFICATION OF THEODOLITES
B.(a)Vernier Theodolite: For reading the graduated
circle if verniers are used ,the theodolite is called as a
Vernier Theodolite
(b) Whereas, if a micrometer is provided to read the
graduated circle the same is called as a Micrometer
Theodolite.
( c )reading directly providing as digital num. if
electronic distance measuring is attached with it then
it’s call total station
Vernier type theodolites are commonly used .
10
7. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
SIZE OF THEODOLITE
A theodolite is designated by diameter of the
graduated circle on the lower plate.
The common sizes are 8cm to 12 cm while 14 cm to
25 cm instrument are used for triangulation work.
Greater accuracy is achieved with larger
theodolites as they have bigger graduated circle with
larger divisions hence used where the survey works
require high degree of accuracy.
11
8. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
USES OF THEODOLITE
The Theodolite is a most accurate surveying
instrument mainly used for :
• Measuring horizontal and vertical angles.
• Locating points on a line.
• Prolonging survey lines.
• Finding difference of level.
• Setting out grades
• Ranging curves
• Tacheometric Survey
4
11. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
DESCRIPTION OF A
TRANSIT VERNIER THEODOLITE
A Transit vernier theodolite essentially consist of the
following :
1. Levelling Head. 6. T- Frame.
2. Lower Circular Plate. 7. Plumb –bob.
3. Upper Plate. 8. Tripod Stand.
4. Telescope.
5. Vernier Scale.
12
12. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A TRANSIT VERNIER THEODOLITE.
1.Centering : Centering means setting the
theodolite exactly over an instrument- station
so that its vertical axis lies immediately above
the station- mark. It can be done by means of
plumb bob suspended from a small hook
attached to the vertical axis of the theodolite.
The centre shifting
arrangement if provided with the instrument
helps in easy and rapid performance of the
centring.
13
13. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
2. Transiting :
Transiting is also known as plunging or
reversing. It is the process of turning the
telescope about its horizontal axis through 1800
in the vertical plane thus bringing it upside
down and making it point , exactly in opposite
direction.
14
14. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
3. Swinging the telescope
It means turning the telescope about its
vertical axis in the horizontal plane.
A swing is called right or left according as the
telescope is rotated clockwise or counter
clockwise.
15
15. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
4. Face Left
If the vertical circle of the instrument is on
the left side of the observer while taking a
reading ,the position is called the face left and
the observation taken on the horizontal or
vertical circle in this position, is known as the
face left observation
16
16. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
5. Face Right
If the vertical circle of the instrument is on
the right side of the observer while taking a
reading ,the position is called the face right and
the observation taken on the horizontal or
vertical circle in this position, is known as the
face right observation.
17
17. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
6. Changing Face
It is the operation of bringing the vertical
circle to the right of the observer ,if originally it
is to the left , and vice – versa.
It is done in two steps; Firstly revolve the
telescope through 1800
in a vertical plane and
then rotate it through 1800
in the horizontal
plane i.e first transit the telescope and then
swing it through 1800
.
18
18. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
7. Line of Collimation
LINE OF
COLLIMATION
DIAPHRAGM
TELESCOPE
It is also known as the line of sight .It is an
imaginary line joining the intersection of the
cross- hairs of the diaphragm to the optical
centre of the object- glass and its continuation.
19
19. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
8. Axis of the telescope
AXIS OF THE TELESCOPE
TELESCOPE
It is also known an imaginary line joining the
optical centre of the object- glass to the centre
of eye piece.
OBJECT GLASS
.
20
20. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
9. Axis of the Level Tube
It is also called the bubble line.
It is a straight line tangential to the longitudinal
curve of the level tube at the centre of the tube.
It is horizontal when the bubble is in the centre.
21
21. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TERMS USED IN MANIPULATING A
TRANSIT VERNIER THEODOLITE.
10. Vertical Axis
It is the axis about which the telescope can be
rotated in the horizontal plane.
11. Horizontal Axis
It is the axis about which the telescope can be
rotated in the vertical plane.
It is also called the trunion axis.
22
24. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
ADJUSTMENT OF A THEODOLITE
Temporary Adjustment
The temporary adjustments are made at each set
up of the instrument before we start taking
observations with the instrument. There are three
temporary adjustments of a theodolite:-
i) Setting up & Centering.
ii) Levelling.
iii) Elimintion of parallax.
26
26. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
i) general Method. To measure horizontal angle AOB:-
i) Set up the theodolite at station point O
and level it accurately.
ii) Set the vernier A to the zero or 3600
of
the horizontal circle. Tighten the
upper clamp.
iii) Loosen the lower clamp. Turn the
instrument and direct the telescope
towards A to bisect it accurately with
the use of tangent screw. After
bisecting accurately check the reading
which must still read zero. Read the
vernier B and record both the
readings.
o
A B
HORIZONTAL ANGLE AOB
28
27. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
i) General Method. To measure horizontal angle AOB:-
iv) Loosen the upper clamp and turn the
telescope clockwise until line of sight
bisects point B on the right hand side.
Then tighten the upper clamp and
bisect it accurately by turning its
tangent screw.
v) Read both verniers. The reading of the
vernier a which was initially set at
zero gives the value of the angle AOB
directly and that of the other vernier
B by deducting 1800
.The mean of the
two vernier readings gives the value of
the required angle AOB.
o
A B
HORIZONTAL ANGLE AOB
29
28. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
i) general Method. To measure horizontal angle AOB:-
vi) Change the face of the instrument
and repeat the whole process. The
mean of the two vernier readings
gives the second value of the angle
AOB which should be approximately
or exactly equal to the previous value.
vii) The mean of the two values of the
angle AOB ,one with face left and the
other with face right ,gives the
required angle free from all
instrumental errors.
o
A B
HORIZONTAL ANGLE AOB
30
29. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
ii) Repetition Method.
This method is used for very accurate
work. In this method ,the same angle
is added several times mechanically
and the correct value of the angle is
obtained by dividing the accumulated
reading by the no. of repetitions.
The No. of repetitions made usually in
this method is six, three with the face
left and three with the face right .In
this way ,angles can be measured to a
finer degree of accuracy than that
obtainable with the least count of the
vernier.
o
A B
HORIZONTAL ANGLE AOB
31
30. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
ii) Repetition Method.
To measure horizontal angle by
repetitions:-
i) Set up the theodolite at starting point
O and level it accurately.
ii) Measure The horizontal angle AOB.
iii) Loosen the lower clamp and turn the
telescope clock – wise until the object
(A) is sighted again. Bisect B
accurately by using the upper tangent
screw. The verniers will now read the
twice the value of the angle now.
o
A B
HORIZONTAL ANGLE AOB
32
31. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
ii) Repetition Method contd...
iv) Repeat the process until the angle is
repeated the required number of times
(usually 3). Read again both verniers .
The final reading after n repetitions
should be approximately n X (angle).
Divide the sum by the number of
repetitions and the result thus obtained
gives the correct value of the angle AOB.
v) Change the face of the instrument.
Repeat exactly in the same manner and
find another value of the angle AOB. The
average of two readings gives the
required precise value of the angle AOB.
o
A B
HORIZONTAL ANGLE AOB
33
32. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
iii) Reiteration Method.
o
A
B
Reiteration Method
C
D
This method is another precise and
comparatively less tedious method
of measuring the horizontal angles.
It is generally preferred when
several angles are to be measured
at a particular station.
This method consists in measuring
several angles successively and
finally closing the horizon at the
starting point. The final reading of
the vernier A should be same as its
initial reading.
34
33. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
iii) Reiteration Method.
o
A
B
Reiteration Method
C
D
…If not ,the discrepancy is equally
distributed among all the
measured angles.
Procedure
Suppose it is required to measure
the angles AOB,BOC and COD.
Then to measure these angles by
repetition method :
i) Set up the instrument over
station point O and level it
accurately.
35
34. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
iii) Reiteration Method.
o
A
B
Reiteration Method
C
D
Procedure
ii) Direct the telescope towards
point A which is known as
referring object. Bisect it
accurately and check the reading
of vernier as 0 or 3600
. Loosen the
lower clamp and turn the telescope
clockwise to sight point B exactly.
Read the verniers again and The
mean reading will give the value of
angle AOB.
iii) Similarly bisect C & D
successively, read both verniers at-
36
35. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF HORIZONTAL ANGLES:
iii) Reiteration Method (contd.).
o
A
B
Reiteration Method
C
D
Procedure. each bisection, find the
value of the angle BOC and COD.
iv) Finally close the horizon by sighting
towards the referring object (point
A).
v) The vernier A should now read 3600
.
If not note down the error .This error
occurs due to slip etc.
vi) If the error is small, it is equally
distributed among the several angles .If
large the readings should be discarded
and a new set of readings be taken.
37
36. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF VERTICAL ANGLES:
Vertical Angle : A vertical angle is an angle between
the inclined line of sight and the horizontal. It may be an
angle of elevation or depression according as the object is
above or below the horizontal plane.
A
B
O O
A
B
A
B
O
HORI. LINE
HORI. LINE
β
HORI. LINE
VERTICAL ANGLE
Fig.a
Fig. b Fig. c
AOB= α+ β
AOB= α - β
38
β
β
α
α
α
37. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF VERTICAL ANGLES:
To Measure the Vertical Angle of an object A at a station O:
(i) Set up the theodolite at station point O and level it
accurately with reference to the altitude bubble.
(ii) Set the zero of vertical vernier exactly to the zero of the
vertical circle clamp and tangent screw.
(iii) Bring the bubble of the altitude level in the central position
by using clip screw. The line of sight is thus made horizontal
and vernier still reads zero.
(iv) Loosen the vertical circle clamp screw and direct the
telescope towards the object A and sight it exactly by using
the vertical circle tangent screw.
39
38. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF VERTICAL ANGLES:
(v) Read both verniers on the vertical circle, The mean of
the two vernier readings gives the value of the required
angle.
(vi) Change the face of the instrument and repeat the
process. The mean of of the two vernier readings gives the
second value of the required angle.
(vii) The average of the two values of the angles thus
obtained, is the required value of the angle free from
instrumental errors.
40
39. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF VERTICAL ANGLES:
For measuring Vertical Angle between two points A &B
i) Sight A as before , and take the mean of the two vernier
readings at the vertical circle. Let it be α
ii) Similarly, sight B and take the mean of the two vernier
readings at the vertical circle. Let it be
iii) The sum or difference of these dings will give the value of the
vertical angle between A and B according as one of the points is
above and the other below the horizontal plane. or both points
are on the same side of the horizontal plane Fig b & c
41
β
40. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF DEFLECTION ANGLES:
ANGLE BETWEEN PROLONGATION LINE AND
SERVEY LINE IT’S CALL :
39
This method is suitable for open traverse and is mostly employed in the survey of
rivers, coast line, roads, railways, canals, etc
41. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
MEASUREMENT OF Direct angle methodMEASUREMENT OF Direct angle method
39
This method is similar to the method of included angles explained in the
precending section.
However, in this method, direct angles or the angles to the right are
measured.
This method is generally used in open traverse.
42. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
READING MAGNETIC BEARING OF A LINE
To find the bearing of a line AB as shown in fig .below
i) Set up the instrument over A and level it accurately
ii) Set the vernier to the zero of the horizontal circle.
N
A
B
Fig.
Magnetic Bearing of a Line
iii) Release the magnetic needle and loosen the
….. lower clamp.
iv) Rotate the instrument till magnetic needle
points to North. Now clamp the lower clamp with
the help of lower tangent screw .Bring the needle
exactly against the mark in order to bring it in
magnetic meridian. At this stage the line of sight
will also be in magnetic meridian.
42
43. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
READING MAGNETIC BEARING OF A LINE
iv) Now loose the upper clamp and point the
telescope towards B .With the help of upper
tangent screw ,bisect B accurately and read both
the verniers .The mean of the two readings will be
recorded as magnetic bearing of line.
N
A
B
Fig.
Magnetic Bearing of a Line
v) Change the face of the instrument
for accurate magnetic bearing of the
line and repeat .the mean of the two
values will give the correct bearing of
the line AB.
43
44. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
PROLONGING A STRAIGHT A LINE
There are two methods of prolonging a given line such as AB
(1) Fore sight method ,and (2) Back Sight Method
Fig.
(1)Fore Sight Method. As shown in the fig. below
A B C D Z
i) Set up the theodolite at A and level it accurately .Bisect the
point b correctly. Establish a point C in the line beyond B
approximately by looking over the top of the telescope and
accurately by sighting through the telescope.
ii) Shift the instrument to B ,take a fore sight on C and establish
a point D in line beyond C.
iii) Repeat the process until the last point Z is reached.
44
45. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
PROLONGING A STRAIGHT A LINE
(2) Back Sight Method. As shown in the fig. below
A B C D Z
i) Set up the instrument at B and level it accurately .
ii) Take a back sight on A.
iii) Tighten the upper and lower clamps, transit the telescope
and establish a point C in the line beyond B.
iv) Shift the theodolite to C ,back sight on B transit the telescope
and establish a point D in line beyond C. Repeat the process
until the last point ( Z) is established.
C’
D’
45
46. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
PROLONGING A STRAIGHT A LINE
(2) Back Sight Method.(contd.) As shown in the fig. below
A B C D Z
Now if the instrument is in adjustment, the points
A,B,C,D and Z will be in one line, which is straight but if
it is not in adjustment i.e. line of collimation is not
perpendicular to the horizontal axis ,then C’, D’ and Z’
will not be in a straight line.
C’
D’
46
47. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
PROLONGING A STRAIGHT A LINE
Double reversing Method
A B C D Z
When the line is to be prolonged with high precision
or when the instrument is in imperfect adjustment, the
process of double sighting or double reversing, is used.
Suppose the line AB is to be prolonged to a point Z.
Procedure: As shown below:
C1
C2
D1
D2
Double Sighting / Reversing Method
47
48. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
PROLONGING A STRAIGHT A LINE
Double reversing Method
i) Set up the theodolite at B and level it accurately.
ii) With the face of instrument left, back sight on A and
…. clamp both the upper and lower motions.
iii) Transit the telescope and set a point C1 ahead in line.
A B C D Z
C1
C2
D1
D2
Double Sighting / Reversing Method
48
49. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
PROLONGING A STRAIGHT A LINE
Double reversing Method (contd.)
iv) Loosen the lower clamp ,revolve the telescope in the
horizontal plane and back sight on A .Bisect A exactly by
using the lower clamp and its tangent screw. Now the face of
instrument is right.
v) Transit the telescope and establish a point C2 in line
beside the point C1.
A B C D Z
C1
C2
D1
D2
Double Sighting / Reversing Method
49
50. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
PROLONGING A STRAIGHT A LINE
Double reversing Method (contd.)
vi) The exact position of the true point C must be mid-way
…..between C1 and C2 .
vii) Measure C1 C2 and establish a point C exactly mid-way,
….which lies on the true prolongation of AB.
A B C D Z
C1
C2
D1
D2
Fig. Double Sighting / Reversing Method
50
51. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
PROLONGING A STRAIGHT A LINE
Double reversing Method (contd.)
viii) Shift the instrument to C, double sight on B ,establish the
…..point D1 and D2 and locate the true point D as before .
ix) Continue the process until the last point Z is established.
A B C D Z
C1
C2
D1
D2
Double Sighting / Reversing Method
51
52. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
Theodolite Traversing
A traverse is a series of connected lines whose
lengths and directions are measured in the fiel
The system of surveying in which the angles are
measured with the help of a theodolite, is called
Theodolite surveying
39
Different methods of Traversing
1.Traversing by included angles
2.Traversing by deflection angles
53. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TRAVERSING BY INCLUDED ANGEL METHOD
39
This method is more accurate than
the fast needle method. Traversing
by the method of included angles is
the most commonly used method.
In this method, the magnetic
bearing of any one line is measured
in the field.
54. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
TRAVERSING BY DEFLECTION ANGLES:
39
This method is suitable for open traverse and is mostly employed in the survey of
rivers, coast line, roads, railways, canals, etc
55. THEODOLITE SURVEYINGTHEODOLITE SURVEYING 39
This method is more accurate than
the fast needle method. Traversing
by the method of included angles is
the mostIf the condition of a closed
traverse are not satisfied, there is an
error of closer.
The distance by which a traverse
fails to close is known as ‘Closing
error’ or ‘ Error of closure’.
commonly used method.
In this method, the magnetic
bearing of any one line is measured
in the field.
Closing Errors
56. THEODOLITE SURVEYINGTHEODOLITE SURVEYING 39
1. Latitude:-
The Latitude of
a line is its orthographic
projection on the N-S axis
representing the meridian.
2. Departure:-
The
departure of a line its
orthograohic projection on
the axis perpendicular to
the meridian.
Computation of latitude and departure
57. THEODOLITE SURVEYINGTHEODOLITE SURVEYING
Balancing of Traverse
A traverse is balanced by applying corrections to
latitudes and departures. This is called balancing a
traverse. In case of closed traverse, the algebraic
sum of latitudes and departures must be equal to
zero.
The following are common methods of adjusting a
traverse:-
1. Bowditch’s Rule
2. Transit Rule
39