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basics_of_surveying.mdi

SURE 110 - Fundamentals of Surveying

Basics of Surveying 1

BASICS OF SURVEYING

Robert BurtchSurveying Engineering DepartmentFerris State University

DEFINITION The art and science of making such

measurements as are necessary to determine the relative position of points above, on, or beneath the surface of the earth, or to establish such points in a specified position

Surveyor needs understanding of rigorous mathematical to analyze and

adjust scientific principles underlying and

affecting measurements

SURE 110 - Fundamentals of Surveying

Basics of Surveying 2

BRANCHES OF SURVEYING

Geodetic Surveying Branch of surveying

in which account is taken of figure and size of earth

Plane Surveying Branch of surveying

in which the surface of the earth is considered a plane surface

PHASES OF SURVEYING

Field Work Data procurement phase

Office Work data are Analyzed Reduced to useful form by mathematical

calculations Adjusted Frequently converted to graphical mode of

expression

SURE 110 - Fundamentals of Surveying

Basics of Surveying 3

KINDS OF SURVEYSProperty surveys Determine boundary lines, location of

property corners, acquisition of data to prepare land subdivisions

Route surveys Designing and constructing engineering

projects associated with transportation and communications

Industrial surveys Surveys in aircraft and other industries

where accurate dimensional layouts necessary

KINDS OF SURVEYS Topographic surveys Collect field data to prepare topographic

mapsHydrographic surveys Map shorelines of water bodies, chart

bottom areas of streams, lakes, harbors, etc., measure flow of rivers, assess other issues related to navigation and water resources

Aerial surveys (photogrammetry) Use photographs mounted in specially

designed planes

SURE 110 - Fundamentals of Surveying

Basics of Surveying 4

KINDS OF SURVEYSMine surveys Determine position of underground works

and surface mines, fix position and direction of tunnels and shafts, define surface boundaries

Construction surveys Performed during building of structure or

project to fix elevations, horizontal position, and dimensions

Control surveys Provide basic horizontal and vertical

position data for engineering mission

KINDS OF SURVEYS Final (As Built) survey Tie in features that have just been

constructed to provide final record of construction and to check that construction has proceeded according to design plan

SURE 110 - Fundamentals of Surveying

Basics of Surveying 5

BASIC SURVEY MEASUREMENTS: DEFINITIONS

Direction of gravity used as reference direction Vertical means direction of gravity Horizontal means direction

perpendicular to gravity

SURVEY GEOGRAPHIC REFERENCE Latitude ()

Lines run east-west parallel to equator

Max angle 90 South latitudes

negative Longitude ()

Lines run north south, converge at poles

0 - Greenwich Measured east and

west - 180 max angle West longitude

negative

SURE 110 - Fundamentals of Surveying

Basics of Surveying 6

DEFINITIONS Oblate Spheroid

Ellipsoid of Revolution

Solid obtained by rotating an ellipse on its shorter axis

Idealized figure of earth

DEFINITIONS Level surface (geoid) Continuous surface that is at all points

perpendicular to the direction of gravity Can be thought of as the surface of large

body of water at complete rest (unaffected by tides, etc.)

Elevation Vertical distance above or below a given

reference level surfaceDifference in elevation Vertical distance between two level

surfaces containing the two points

SURE 110 - Fundamentals of Surveying

Basics of Surveying 7

DEFINITIONS Vertical line

Line following direction of gravity

Vertical line passing through several different points on surface of earth do not intersect at a common point

Vertical lines not necessarily normal to surface of the earth

Deflection of vertical Angle between

perpendicular to geoidand ellipsoid

DEFINITIONSHorizontal line Line perpendicular to vertical line at a point

Horizontal plane Plane perpendicular to vertical line at point Only 1 horizontal plane through a given

pointVertical plane Plane containing vertical line at the point Infinite number of vertical planes as a

given point

SURE 110 - Fundamentals of Surveying

Basics of Surveying 8

DIRECTION Azimuth- clockwise

angle from north to line

Bearing angle measured from north or south to east or west

ACCURACY & PRECISION

Accuracy closeness between measurement and true value

Precision closeness to one another of a set of repeated observations

SURE 110 - Fundamentals of Surveying

Basics of Surveying 9

ERRORS

No measurement free of error (except counting)

Mistakes or blunders Not really errors because they are usually

so gross in magnitude Most common reason carelessness Must be discovered and eliminated

ERRORSSystematic error Occur according to a system which can be

expressed mathematically Magnitude and sign can be determined Follow definite pattern Can be caused by observer, instrument,

environmentRandom error Error left after systematic error removed May tend to cancel themselves

SURE 110 - Fundamentals of Surveying

Basics of Surveying 10

UNITS OF LENGTH

Imperial units (feet) Usually

subdivided into decimal units in surveying

Use of inches

SI units (meters) Le Systeme

Internationale dUnites(International System of Units

Normally subdivided into decimeter, centimeter, millimeter

NORMAL PREFIXES FOR METER exa (E) 1018 peta (p) 1015 tera (t) 1012 giga (g) 109 mega (m) 106 kilo (k) 103 hecto (h) 102 deka (da) 101

Ex: kilometer = 1,000m

deci (d) 10-1 centi (c) 10-2 milli (m) 10-3 micro ()10-6 nana (n) 10-9 pico (p) 10-12 femto (f) 10-15 atto (a) 10-18

Ex: millimeter = 0.001m

SURE 110 - Fundamentals of Surveying

Basics of Surveying 11

METRIC SYSTEM

1791 French Academy of Sciences recommended metre to be 1/10,000,000th part of polar quadrant passing through Paris

1799 Academy of Sciences developed new standard Metre of the Archives made of platinum 1 meter in length

1999 General Conference of Weights and Measures adopts International Prototype Metre platinum & iridium bar

METRIC SYSTEM

1960 National Prototype Meter 1,650,763.73 wavelengths of Krypton 86 atom in a vacuum

1983 Conference Generale des Poids et Mesures redefined meter as length of the path traveled by light in a vacuum during a time interval of 1/299792458 of a second

SURE 110 - Fundamentals of Surveying

Basics of Surveying 12

FEET-METER CONVERSION

FEET-METER CONVERSION Ferdinand Hassler brought iron meter

bar to U.S. in 1805 for work with Coast Survey

1866 Congress legalized use of metric system

1893 Mendenhall Order Superintendent of Weight & Measures 1 meter = 39.37 inches (exact) 1 U.S. Yard = (3600/3927) meter (exact)

SURE 110 - Fundamentals of Surveying

Basics of Surveying 13

FEET-METER CONVERSION 1959 U.S. & U.K. agreed that Imperial

units used in both countries should be the same Defined 1 Yard = 0.9144 metre (exact) 1 ft = 0.3048 m (exact) 1 inch = 25.4 mm (exact) Did not change relationship established by

Congress kept for surveying and called U.S. Survey foot