Surveying
SURVEYING, Classification of survey based on the curvature of the earth surface- Plane Survey, Geodetic Survey. Classification of survey based on Place– Land Survey (Topographical Survey, Cadastral Survey, City Survey), Hydrographical Survey, Astronomical Survey. Classification of survey based on Purpose- Engineering Survey, Military Survey, Archaeological Survey, Mine Survey, Geological Survey. Classification of survey based on Instrument- Chain Survey, Compass Survey, Levelling, Plane table Surveying, Theodolite Survey, Tacheometric Survey, Photogrammetric Survey, EDM (Electronic Distance Measurement) Survey. Principal of surveying– Working From Whole To Part, Location of a Point by With Respect to Reference Point. Instruments Used for Various Types of Measurement.
Plan & Map, SCALE, Representation of Scale- Engineer’s Scale, Representation Fraction (RF), Graphical Scale. Shrinkage Factor or Shrinkage Ratio, Error Due to Shrinkage of Map, Error Due to Wrong Measuring Scale, Type of Scales- Plane Scale, Diagonal Scale, Vernier Scale (Direct Vernier, Retrograde Vernier, Extended Vernier, Double Vernier).
Linear Measurements, Procedure in Chain Surveying,Basic Definition of Chain Surveying- Main Station, Tie Station, Main Survey Line, Tie Line/ Subsidiary Line, Base Line, Check Line/ Proof Line, Offset, Chainage, Well Conditioned Triangle. Linear Measurement with Chain- On Smooth Level Ground, On Sloping Ground. Errors & Correction in Chaining/ Taping, Type of Error in Chaining, Correction in Chaining & Taping Are Following Type- Correction For Standardisation, Correction for Slope (Cg), Correction for Pull (Tension), Correction for Temperature (Ct), Correction for Sag (Csag), Reduction of length to mean sea level (MSL), Field Work in Chain Surveying- Reconnaissance, Marking of Stations, Running Survey Lines, Taking Offsets. Limiting Length of Offsets- Error only in laying offset, Error in laying direction and liner measurement.
Equipment Used In Chain Surveying, Surveying Chain, Types of Chain- Revenue chain, Gunter’s chain, Engineer’s chain, Metric chain, Suitability of Chain, Unsuitability of Chain, Units of Measurement, Tapes-Cloth or Linen Tape, Metallic Tape, Steel Tape, Invar Tape, Pegs, Arrows, Ranging rods, Offset rods, Plumb bob, Clinometer, Cross-staff, Optical Square, Prism Square, Chain Survey Instruments, Distance Measuring Device, Instruments Used for Various Types of Measurement
Compass Surveying, Basic difference between chain and compass surveying, Classification of Traverse- Closed Traverse, Open Traverse. Compass traverse, Meridian– True Meridian, Magnetic meridian, Grid Meridian, Arbitrary Meridian. Bearing, Types of bearing- True Bearing, Magnetic Bearing, Grid Bearing, Arbitrary Bearing. Designation of Bearing or Representation of Bearing- Whole Circle Bearing System, Quadrantal Bearing System.
Fore Bearing And Back Bearing, Relationship Between Fore Bearing And Back Bearing, Include Angle, Magnetic Declination, Type of Declination- Eastern Declination, Western Declination. Variation of Magnetic Declination- Secular Variation, Diurnal Variation, Annual Variation, Irregular Variation. Adjustments Of Angles, Angle of Dip, Local Attraction
Compass, Temporary & Permanent Adjustments Of Compass– Temporary adjustments, Permanent Adjustments. Compass are generally two types- Surveyor Compass, Temporary adjustments of a Surveyor’s Compass- Centring- Levelling. Permanent Adjustment of Surveyor’s compass, Prismatic Compass, Temporary Adjustments of a Prismatic Compass- Centring, Levelling, Focussing, Permanent adjustment of prismatic compass, Difference Between Prismatic Compass and Surveyor Compass
Traverse Survey, Types of Traverse- Closed Traverse, Open Traverse. Method of Traversing– Linear Measurement, Angular Measurements: Loose Needle Method, Fast Needle Method, Method of Included Angle, Method of Direct Angles, Method of Deflection Angles. Balancing the Angle of Traverse- Average Correction Method. Latitude And Departure- Latitude (L), Departure (D). Checks in a Closed Traverse- Loop Traverse, Link Traverse. Closing Error, Relative Error of Closure or Relative Precision, Method to Correct Clothing Error- Bowditch’s Rule, Transit Rule.
Levelling, Important Terminologies In Levelling, Elevation & Altitude, Reduced Level, Mean Sea Level, Bench Marks(B.M)– G.T.S Bench Marks, Permanent Bench Marks, Temporary Bench Marks, Arbitrary Bench Marks. Measurement in Leveling Work- Horizontal Line, Vertical Line, Level Line, Back Sight Reading, Fore Sight Reading, Intermediate Sight Reading. Method to Find Reduced Level- Height of Instrument, Rise and Fall Method. Inverted Staff, Correction Required in Levelling Work- Correction due to Earth Curvature (Cc), Correction due to Refraction (CR), Combined Correction due to Both (C). Distance of Visible Horizon- When height of any one point is considered, When height of both points are considered. Reciprocal Leveling – When the instrument near A, When the instrument near B, Collimation error– When Area is Large, When Area is small, Angular / Inclination Error, Sensitivity of Bubble Tube , The sensitivity of level tube increases with?.
Introduction, Measurement of Area: Computation of Area of Geometrical Figures- Rectangle, Square, Triangle, Circle, Parallelogram, Trapezoid, Trapezium, Oblique Triangle, Area of a Segment, Regular Polygon. Computation of Area of Irregular Shape– Mid Ordinate Rule, Average Offset Rule, Trapezoidal Rule, Simpson’s One Third Rule. Measurement Of Volume : Computation of Volume of Irregular Shape– Trapezoidal Rule / End Area Method, Prismoidal / Simpson’s Rule
Tacheometry, Instrument Used In Tacheometry– Tacheometer, Stadia Rod. Different Systems of Tacheometric Measurement- Stadia System:{Fixed hair system, Movable hair system}, Tangential System, Subtense Bar System, Theory of Tacheometer. Distance and Elevation Through Tacheometer– When a Staff Is Vertical, When a Staff Is Perpendicular to Line of Sight.
Curve, Horizontal curves are generally of three types, Simple Circular Curve, Compound Curve, Reverse Curve, Broken-back Curve, Basic Definitions- Back tangent, Forward tangent, Vertex or point of intersection, Deflection angle, Point of Curvature (P.C.), Point of tangency(P.T.), Tangent distance (T), External distance (E), Long chord (L), Mid ordinate (M), Length of curve (l), Elements of Circular Curve- Length of Tangent (T), Length of Curve (l), Mid Ordinate (M), Length of Chord (L), External Distance (E) Apex Distance, Chainage of Tangent points, Intermediate Chord Length- For 1st chord, For 2nd to (n-1) chord, For Last chord, No of Intermediate Chord
Theory of Errors, Occurrence of Error- Imperfection in Instruments, Environmental Condition, Human Limitations & Carelessness, Type of Error– Gross Errors or Mistakes, Systematic or Cumulative Errors, Accidental or Random errors, Important Terminology- Precision, Accuracy, True Value, True Error, Most Probable Value (M.P.V), Principle of Least Square, Residual Error. Law’s of Weights, Probable Error– Probable Error in Single Measurements, Probable Error in Mean (MPV), Probable Error of Single Measurement of Weight, Error In Computed Result.
Plane Table Surveying, Accessories Used in Plane Table Surveying- Plane Table Board, Alidade (for orientation), Tripod (for stand), Level Tube/ Spirit Level (for leveling), Compass (for orientation), Plumbing Fork (for centering), Procedure, Setting up the Plane Table- Centering, Levelling, Orientation: Orientation with a Trough Compass, Orientation by Back-Sighting, Resection. Method Of Plane Table Survey– Radiation Method, Traversing Method, Intersection Method, Resection Method- Compass Method of Resection, Back Ray Method of Resection, Two Point Problem of Resection, Three Point Problem of Resection.
Triangulation, Classification of Triangulation– Primary / 1st order Triangulation, Secondary/ 2nd order Triangulation, Tertiary/ 3rd order Triangulation. Accuracy of Triangulation Networks, Objective Of Triangulation, Triangulation Layout – Single Chain of Triangulation, Double Chain of Triangulation, Braced Quadrilaterals, Centered Triangle & Polygon. System Of Framework – Grid Iron System, Central System. Well Condition Triangle (***), Trilateration.
Geographic Information System (GIS)-Geographic, Information system, Uses of GIS, Components of GIS- Hardware, Software’s, Data, People, Methods. Global Positioning System (GPS), Different GPS systems available are, Comparison of Global Navigation Satellite Systems of the World. Remote Sensing, Principles of Remote Sensing, Remote Sensing Sensor Systems, Type of Remote Sensing Sensor Systems– Active System, Passive System.
Photogrammetry, Advantage & Disadvantage of Photogrammetry, Types of Photogrammetry- Terrestrial Photogrammetry (Horizontal Photograph), Aerial Photogrammetry. Difference Between a Map and An Aerial Photograph, Types of Photographs- Vertical Photograph, Oblique Photograph. Terminologies in Aerial Surveying– Scale of Photograph, Datum Scale of Photograph, Average Scale of Photograph, Flying Height, Crab, Drift. Ground Co-Ordinates & Length of a Line From a vertical Photograph, Relief Displacement, Area Covered By One Photograph, Number of Photograph Required to Cover an Area – 1.When No overlap is Present, 2.When overlap is Present (Longitudinal & Side)- (I). When Total Ground Area (A) is given, (II). When Length & Width are given of total Ground, Exposure Interval, Air Base.
Theodolite Survey, Applications of Theodolite Survey, Compass Surveying Vs Theodolite Surveying, Classification of Theodolite– Transit Theodolite, Non Transit Theodolite, Vernier Theodolites, Precise Optical Theodolites (Micrometer Theodolite), Components of a Vernier Theodolite, Terminologies in Theodolite Surveying- Centering, Vertical Axis or Azimuth Axis, Horizontal Axis or Trunnion Axis, Axis of the telescope, LOS/LOC, Transiting /Plunging /Reversing, Axis of level tube Bubble line, Swinging, Face left observation, Face Right Observation, Telescope normal , Telescope Inverted, Double Sighting. Fundamental Lines, Temporary Adjustments of Theodolite- Setting, Centring, Leveling, Focusing- 1.Focusing of Eye-piece, 2.Focusing of Objective. Permanent Adjustment of Theodolite, Method to Measure Angles
Topics
A theodolite is an important instrument used for measuring horizontal and vertical angles in surveying. The system of surveying in which the angles (both horizontal & vertical) are measured with the help of a theodolite, is called Theodolite surveying.
In fundamentals of surveying (part-2), we details analysis about plan & map, scale, representation of scale- engineer’s scale, representation fraction (rf), graphical scale. Shrinkage factor or shrinkage ratio, error due to shrinkage of map, error due to wrong measuring scale, type of scales- plane scale, diagonal scale, vernier scale (direct vernier, retrograde vernier, extended vernier, double vernier).