ENG 200 - Surveying

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ENG 200 - Surveying

• Ron Williams
• Website http//web.mnstate.edu/RonWilliams

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Surveying

• The art of determining or establishing the
  relative positions of points on, above, or below
  the earths surface

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Determining or Establishing

• Determining both points already exist -
  determine their relative locations.
• Establishing one point, and the location of
  another point relative to the first, are known.
  Find the position and mark it.
• Most property surveys are re-surveys
• determining
• you have no right to establish the corners

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History of Surveying

• First References
• Dueteronomy 1914
• Code of Hannarubi
• Egyptions used surveying in 1400 b.c. to divide
  land up for taxation
• Romans introduced surveying instruments

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Surveying in America

• Washington, Jefferson, and Lincoln were survyors
• The presence of surveyors meant someone wanted
  land - often traveled with soldiers
• Railroads opened up the country, but surveyors
  led the railroad
• East coast lands were divided by Metes and
  Bounds, the west by US Public Lands

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Types of Surveys

• Plane Surveys
• Assume NS lines are parallel
• Assume EW lines are straight

Geodetic Surveys Allow for convergence Treat EW
lines as great circles Used for large surveys
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Types of Surveys

• Land - define boundaries of property
• Topographic - mapping surface features
• Route - set corridors for roads, etc.
• City - lots and blocks, sewer and water, etc.

• Construction - line and grade for building
• Hydrographic - contours and banks of lakes and
  rivers
• Mines - determine the relative position of shafts
  beneath the earths surface

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Safety Issues

• Sun
• Insects
• Traffic
• Brush cutting
• Electrical lines
• Property owners

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Units of Measure

• Feet
• Inches, 1/4, 1/8, etc.
• 1/10, 1/100, etc.
• 10 4-5/8 10.39
• Measure to nearest .01
• Meters
• 1 foot 0.305 m
• 1 m 3.28
• Stations

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Units of Measure
Rods - 16.5 ft Chains - 66 feet 4 rods
chain Miles - 5280 feet 80 chains 1 mile 320
rods 1 mile Others
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Math Requirements

• Degrees, Minutes, Seconds
• Geometry of Circles
• Trig Functions
• Geometry, Trig of Triangles

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- - to Decimal Degrees

• 1 degree 60 minutes
• 1 minute 60 seconds

• 24 24/60 0.4
• 1524 15.4 15.4/60 0.2567
• 321524 32.2567
• Most calculators do trig calculations using
  decimal degrees - CONVERT!

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Decimal Degrees to DMS

• ? 23.1248
• 0.124860 7.488 minutes
• 0.48860 29.3 seconds
• 23.1248 23729.3
• Watch roundoff!
• 23.1 23600
• We do most work to at least 1 minute!
• Cheap scientific calculator - 12.00

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Geometry of a Circle
Total angle 360
4 quadrants - NE, SE, SW, NW - each total 90
Angles typically measured East from North or East
from South
Clockwise (CW) and Counterclockwise (CCW) angles
add to 360
360 - 2318 33642
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Geometry of a Circle

• Transit sited along line AB, 10515 clockwise
  from North.

• Transit is turned 13542 counterclockwise to
  site on C.

• Determine the direction of line AC.
• 10515 - 13542 -3027
• Counterclockwise angle gets smaller
• Negative result add 360
• -3027 360 32933

B

• Or 360 - 13542 22418

• 10515 22418 32933

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Trig Functions

• Sin, Cos, Tan are ratios relating the sides of
  right triangles
• o - side opposite the angle

• a - side adjacent to the angle

h

• h - hypotenuse of triangle

o

• Sin ? o/h

• Cos ? a/h

• Tan ? o/a

a
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Using Trig Functions

• Line AB bears 7214 East of North
• Length of AB, lAB 375.46
• Determine how far North and how far East B is
  from A

• Cos? a/h, a hCos?
• NB/A lAB Cos(7214) 115.15

• Sin? o/h o hSin?
• EB/A lAB Sin(7214) 357.37

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Triangle Geometry, Trig Laws

• Sum of interior angles 180
• Sine law

• if A B, ? ?
• Cosine law

• if ? 90, A2 B2 C2