History of Surveying
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One if the oldest profession in the world
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Around 1400 B.C., Egypt was divided into plots for the purpose of taxation.
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Surveyors were called rope-stretchers.
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Around 120 B.C., Greek thinkers developed first surveying equipment (Diopter).
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Diopter is the ancestor of the modern theodolite.
What is Surveying?
-Surveying is the art and science of determining angular and linear measurements to
establish the form, extent and relative position of points, lines and areas on or near the
surface of the earth.
Objectives of Surveying:
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To prepare a map or plan. To show the relative position of the objects on the
surface of the Earth.
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To establish the boundaries of the land.
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To select a suitable site for an engineering project.
General Classification:
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Plane Surveying
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The earth is considered to be a flat surface.
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The exact shape or curvature of the earth is disregarded
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The line joining two stations is considered as a straight line.
GEODETIC SURVEYING
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It takes into account the spheroidal shape of the Earth.
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Is of high accuracy
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The line joining any two stations is considered as a curved line.
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The triangle formed by any three points is considered as spherical

The angles of the triangle are considered to be spherical
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Carried out for a large area >250 sq. km.
Types of Surveys
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City Survey
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Construction Surveys
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undertaken at a construction site.
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provides data about grades, reference lines, dimensions, elevation of
structure, etc.
Forestry Survey
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forest management and mensuration
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production and conservation of forest lands
Hydrographic Survey
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surveying streams, lakes, reservoirs, oceans, and other bodies of water.

map shorelines, measure flow of streams use for navigation, development
of water supply, flood control, irrigation, etc.
Mine Survey
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for planning expansions, locating property lines, configuration of the land
etc
Determine the position of all underground excavations and surface mine
structures, flx surface boundaries of mining claims, determine geological
formations, etc.
Topographic Survey
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Determine the shape of the ground, the location and elevation of natural
and artificial features upon it.
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The features include natural objects such as hills, mountains, rivers, lakes,
etc.
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Cadastral Survey
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Undertaken in urban and rural areas
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Defining property lines and boundaries
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Fix boundaries of municipalities, town and provincial jurisdictions.
Industrial Survey
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Known as optical tooling
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Ship building, aircraft construction, installation of heaty and complex
machinery, etc.
Route Survey
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Determination of alignment, grades. Earthwork quantities, location of
natural and artificial objects.
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For the construction of highways, railroads, pipelines, canals, etc
Surveying Measurements and Instrumentation

Measurement is the process of determining the extent, size or dimensions of a
particular quantity in comparison to a given standard.

In surveying, measurements are usually concentrated on angles, elevations,
times, lines, areas, and volumes.
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Any surveying measurement is always subject of the imperfections of the
instrument used and the different errors in the process of measurement.
Types of Measurements
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Direct Measurement- use of the measuring instrument directly to measure the
quantity to be measured
Example:
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Determining a horizontal and vertical angle with a transit
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Fitting a protractor between two intersecting angles.
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Indirect Measurement- the measuring instrument cannot directly measure the
required quantity. It is computed by computing a quantity from direct
observations.
Example:

The total length of the line would be taken from the summation of directly
measured shorts segments.
Units of Measurements
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Significant Figures
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All nonzero digits are significant
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Zeros appearing between nonzero digits are significant
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Zeros appearing before nonzero digits are NOT significant
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Zeros at the end of a number and to the right of a decimal point are
significant
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Zeroes at the end of a number without a decimal point may or may not
significant
Rounding Off Numbers
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If 5 and >5 ad one
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Rule of 5 (if after the number is 5)
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If odd, add 1 (ex. 10.35 = 10.4)
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If even, the value is not changed (10.65 = 10.6)
Surveying Instruments
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Chains and Tapes
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used to measure distances on the field.
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A chain is made up of connected steel segments, or links, which each
measure 20 cm. Usually, a chain has a total length of 20 metres, including
one handle at each end.
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Measuring tapes are made of steel, coated linen, or synthetic material
Centimetres decimetres and metres are usually indicated on the tape.
Plumb Bob
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used to check if objects are vertical. A plumb bob consists of a piece of
metal (called a bob) pointing downwards, which is attached to a cord,
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When the plumb bob is hanging free and not moving, the cord is vertical.
Transits and Theodolites
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These tools are used to measure both horizontal and vertical angles.
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Both tools have a minimum accuracy of one minute of angle, though the
theodolite is generally recognized as the more accurate of the two
measuring angles to an accuracy of one-tenth of a second angle.
Levels
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A carpenter level is used to check if objects are
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horizontal or vertical. Within a carpenter level there
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are one or more curved glass tubes, called level
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Tubes
Ranging Poles
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used to mark areas and to set out straight lines on the field.
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They are also used to mark points which must be seen from a distance, in
which case a flag may be attached to improve the visibility.
Poles, Tripods and Mounts
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Poles, tripods, and other mounting accessories are essential for surveyors
to ensure solid, stable readings.
Contents:
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Errors
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Sources of Errors
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Accuracy and Precision
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Most Probable Value
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Probable Error
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Relative (Error) Precision
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Illustrative Problems
Error
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An error is defined as the difference between the true value and measured value
of a quantity.
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Errors are inherent in all measurements and result from sources which cannot be
avoided
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In any surveying operation, the surveyor continuously dealing with errors.
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Types: (a) Systematic errors, (b) Accidental errors
Error (disc) = true value – measured value
INTRUMENTAL ERRORS
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caused by imperfections in the instrument used.
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wear and tear of the instrument.
NATURAL ERRORS
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caused by changing conditions in the surrounding environment.
PERSONAL ERRORS
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caused by physical limitations and inconsistent setup and observation habits of
the surveyor
ACCURACY
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degree of perfection obtained in a measurement.
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absolute nearness of a measured quantity to its true value.
PRECISION
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the closeness of one measurement to another.
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degree of consistency between measurements.
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based on the size of discrepancies in a data set
MOST PROBABLE ERROR (mpv)
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From the theory of probability, the mpv of a group of repeated measurements
made under similar conditions is the arithmetic mean or the average.
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mpv refers to a quantity which, based on available data, has more chances of
being correct than has any other.
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mvp is determined using the following equation:
PROBABLE ERROR
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It is a quantity which, when added to and subtracted from the most probable
value, defines a range within which there is a 50 percent chance that the true
value of the measured quantity lies inside (or outside) the limits thus set.
RELATIVE PRECISION
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It is expressed by a fraction having the magnitude of the error in the numerator
and the magnitude of a measured quantity in the denominator.
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The numerator is reduced to unity or 1 in order to provide an easy comparison
with other measurement.
Contents:
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Measurement of Distance
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Distance by Pacing
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Distance by Taping
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Distance by Tachymetry
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o
Stadia Method
o
Subtense Bar Method
Distance by Graphical and Mathematical Method
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Distance by Mechanical Devices
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Illustrative Examples
Measurement of Distance
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In plane surveying, the distance between two points means the horizontal
distance
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If the points are at different elevations, the distance is the horizontal length
between plumb lines at the points.
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Methods of linear measurement include pacing, taping, tachymetric, graphical,
mathematical, mechanical, photogrammetric, electronic distance measurement
(EDM).
Distance by Pacing
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Pacing consists of counting the number of steps or paces in required distance.
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A pace is defined as the length of a step in walking ( from heel to heel or from toe
to toe).
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Counting strides instead of paces is sometimes preferred by surveyors.
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A stride is equivalent to two paces or a double step.
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Distance is calculated by multiplying the number of paces by the individual's pace
factor (m/pace).
Advantages:
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Simple
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Low tech
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No specialized equipment
Disadvantages:
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Topography affects accuracy.
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Requires practice to take a consistent pace.
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Must be able to travers the distance.
Distance by Taping
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Formerly known as chaining, taping is the use of a graduated tape is the most
common method of measuring/ laying out horizontal distance.
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Taping consists of stretching a calibrated tape between two points and reading
the distance indicated on the tape.
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It is widely used in the construction of buildings, dams, bridges, canals, etc.
Distance by Tachymetry
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Tachymetry (or tacheometry) is based on the optical geometry of the instruments
employed and is an indirect method of measurement.
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It is performed either by (a) stadia method or the (b) subtense bar method.
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The stadia method measures distance by line of sight through an instrument.
When the measurement is level, the distance measured is a horizontal distance.
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In this method, a bar of fixed length, called a subtense bar is placed in horizontal
position. The horizontal distance between the subtense bar and the instrument is
computed from the known distance between the targets and the measured
horizontal angle.
Distance by Graphical and Mathematical Methods
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By graphical or mathematical methods, unknown distances may be determined
through their relationship with the known distances geometrically.
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These methods are widely employed in plane table surveys, and in triangulation
work.
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It involves geometric and trigonometric relationships.
Distance by Mechanical Devices

There are few mechanical devices which could also be employed for the
measurement of distances.
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These devices, however, are only applicable for low precision surveys or where
quick measurements are desired.
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Commonly used devices include (a) odometer, (b) measuring wheel and the (c)
optical rangefinder.
Distance by Photogrammetry
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The term photogrammetry refers to the measurement of images on a
photograph.
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The type of photographs used are those taken from an aircraft with the axis of
the camera pointed vertically towards the terrain photographed.