basics of surveying
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SURE 110 - Fundamentals of Surveying
Basics of Surveying 1
BASICS OF SURVEYING
Robert BurtchSurveying Engineering DepartmentFerris State University
DEFINITIONThe 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 positionSurveyor needs understanding of
rigorous mathematical to analyze and adjustscientific principles underlying and affecting measurements
SURE 110 - Fundamentals of Surveying
Basics of Surveying 2
BRANCHES OF SURVEYING
Geodetic SurveyingBranch of surveying in which account is taken of figure and size of earth
Plane SurveyingBranch of surveying in which the surface of the earth is considered a plane surface
PHASES OF SURVEYING
Field WorkData procurement phase
Office Work – data areAnalyzedReduced to useful form by mathematical calculationsAdjustedFrequently 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 surveysDesigning and constructing engineering projects associated with transportation and communications
Industrial surveysSurveys in aircraft and other industries where accurate dimensional layouts necessary
KINDS OF SURVEYSTopographic surveys
Collect field data to prepare topographic maps
Hydrographic surveysMap 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 surveysPerformed during building of structure or project to fix elevations, horizontal position, and dimensions
Control surveysProvide basic horizontal and vertical position data for engineering mission
KINDS OF SURVEYSFinal (“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 gravityHorizontal – means direction perpendicular to gravity
SURVEY GEOGRAPHIC REFERENCE Latitude (φ)
Lines run east-west parallel to equatorMax angle 90°South latitudes negative
Longitude (λ)Lines run north south, converge at poles0° - GreenwichMeasured east and west - 180° max angleWest longitude negative
SURE 110 - Fundamentals of Surveying
Basics of Surveying 6
DEFINITIONSOblate Spheroid
Ellipsoid of RevolutionSolid obtained by rotating an ellipse on its shorter axisIdealized figure of earth
DEFINITIONSLevel surface (geoid)
Continuous surface that is at all points perpendicular to the direction of gravityCan be thought of as the surface of large body of water at complete rest (unaffected by tides, etc.)
ElevationVertical distance above or below a given reference level surface
Difference in elevationVertical distance between two level surfaces containing the two points
SURE 110 - Fundamentals of Surveying
Basics of Surveying 7
DEFINITIONSVertical line
Line following direction of gravityVertical line passing through several different points on surface of earth do not intersect at a common pointVertical lines not necessarily normal to surface of the earth
Deflection of verticalAngle between perpendicular to geoidand ellipsoid
DEFINITIONSHorizontal line
Line perpendicular to vertical line at a pointHorizontal plane
Plane perpendicular to vertical line at pointOnly 1 horizontal plane through a given point
Vertical planePlane containing vertical line at the pointInfinite number of vertical planes as a given point
SURE 110 - Fundamentals of Surveying
Basics of Surveying 8
DIRECTIONAzimuth- 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” valuePrecision –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 blundersNot really errors because they are usually so gross in magnitudeMost common reason – carelessnessMust be discovered and eliminated
ERRORSSystematic error
Occur according to a system which can be expressed mathematicallyMagnitude and sign can be determinedFollow definite patternCan be caused by observer, instrument, environment
Random errorError left after systematic error removedMay 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 surveyingUse of inches
SI units (meters)Le SystemeInternationale d’Unites(International System of UnitsNormally 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 (µ)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 Paris1799 Academy of Sciences developed new standard – Metre of the Archives –made of platinum 1 meter in length1999 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 vacuum1983 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
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FEET-METER CONVERSION
FEET-METER CONVERSIONFerdinand Hassler brought iron meter bar to U.S. in 1805 for work with Coast Survey1866 Congress legalized use of metric system1893 – Mendenhall Order
Superintendent of Weight & Measures1 meter = 39.37 inches (exact)1 U.S. Yard = (3600/3927) meter (exact)
SURE 110 - Fundamentals of Surveying
Basics of Surveying 13
FEET-METER CONVERSION1959 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