Any service of work the adequate performance of which involves the application of special knowledge of the principles of mathematics the related physical and applied sciences and the relevant requirements of law for adequate evidence to the act of measuring and locating lines angles elevations ID: 729785
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Slide1
Land SurveyingSlide2
Definition of Surveying in the State of Tennessee (T.C.A. 62-18-102)
Any service of work, the adequate performance of which involves the application of special knowledge of the principles of mathematics, the related physical and applied sciences, and the relevant requirements of law for adequate evidence to the act of measuring and locating lines, angles, elevations, natural and man-made features …for the purpose of determining areas and volumes, for the
monumenting
of property boundaries, and for the platting and layout of lands and subdivisions thereof, including the topography, drainage, alignment and grades of streets, and for the preparation and perpetuation of maps, records, plats, field notes, records and property descriptions that represent these surveys.Slide3
Famous Land Surveyors
George Washington
Surveyor General in Virginia, 1749
Thomas Jefferson
County Surveyor for Albemarle County, VA, 1773
Lewis and Clark
Expedition to explore and survey the west
Daniel Boone
Resolved Kentucky land disputes
Abraham Lincoln
Surveyor in Illinois when elected to state legislatureSlide4
Land Surveying
The science of determining the relative positions of points on the Earth’s surface.
Geodetic Surveys
Plane SurveysSlide5
Geodetic Survey
Takes into account the true size, shape, and gravity fields of the Earth
The
geoid
is the equipotential surface of the Earth’s gravity field which best fits global mean sea level
Provides significant precision
Establishes highly accurate control networks
Images courtesy NOAA
http://celebrating200years.noaa.gov/foundations/gravity_surveys/Slide6
Plane Survey
Assumes the Earth’s surface to be a plane (flat)
More common than geodetic surveys
Precise enough for small-scale surveys in a limited area, such as a construction site
Used to determine legal boundaries, construction surveys, and small-area topographic or control surveys
©iStockphoto.comSlide7
Horizontal Plane
Plumb Line
Rod
Geodetic Survey
Line of equal elevation
Plane Survey
Line of equal elevation
Geoid or other Datum
Geodetic vs. Plane Survey
Earth’s surface
RodSlide8
Types of Surveys
Control Survey
Topographic Survey
Property Survey
Site Survey
Construction SurveySlide9
Control Survey
Establish precise horizontal and vertical positions of points that serve as a reference for other surveys
Courtesy Department of Public Works, Seminole County, FL
Photos Courtesy NOAASlide10
Topographic Survey
Gathers data on the location of natural and man-made features, contours, and ground elevation to create a topographic map
Courtesy USGSSlide11
Property Survey
(or Boundary Survey)
Establishes property lines for a lot
Used to create a platSlide12
Site Survey
(Plot Survey or Lot Survey)
Combination of a property survey and topographic survey
May be required to receive a construction permitSlide13
Construction Survey
Locates points and elevations that can be used to establish correct locations and elevations for engineering and architectural projects
Courtesy Isle of Palms, SC Recreation DepartmentSlide14
National Spatial Reference System (NSRS)
Common set of reference points for all surveys
Horizontal Datum
= Collection of points of known latitude and longitude
Vertical Datum
= Collection of points of known elevation
Benchmark (BM)
= Permanent mark that establishes a point of known elevation
Wikimedia.org
Courtesy NOAA http://oceanservice.noaa.gov/education/kits/geodesy/geo05_horizdatum.html Slide15
Reference System Data
Information on datum points available at
http://www.ngs.noaa.gov/cgi-bin/datasheet.prlSlide16
Example Data Sheet Slide17
Optical Equipment
Requires a visual line-of-sight
A
theodolite
measures vertical and horizontal angles
A
total station
is an electronic/optical surveying instrument
©iStockphoto.com
©iStockphoto.comSlide18
Optical Equipment
Automatic (Auto) Level
Commonly used on building sites
Internal compensator can automatically level the instrument
Measures difference in elevation between the line of sight and a point
KennedySlide19
Other Equipment
Courtesy USGS http://gallery.usgs.gov/photos/07_22_2009_j51Qi76Hgb_07_22_2009_13
Tripod
Leveling Rod
Professional Tape Measure
©iStockphoto.com
Field Book
Kennedy
Kennedy
Kennedy
KennedySlide20
GPS Technology
Global Positioning System
A global navigation satellite system
Developed by the U.S. Department of Defense
A constellation of satellites that broadcast radio signals
Receivers intercept several satellite signals in order to determine precise location
Courtesy NASA
Widimedia.comSlide21
GPS
©iStockphoto.com
KennedySlide22
Auto Level
Bulls Eye Level
Telescope
Leveling Screws
Horizontal Angle Rotation Ring
Eyepiece
Horizontal Tangent Knob
Sight
Diopter Adjustment Ring
Mirror
KennedySlide23
Reading the Rod
View through the telescope
Horizontal crosshair
Vertical
crosshair
Stadia hairs
Beveled hatch marksSlide24
Reading the Rod
Upper Stadia Reading = 5.30 ft
Rod Reading = 5.25 ft
Lower Stadia Reading = 5.20 ft Slide25
Stadia Readings
Estimate distance between rod and instrument
Rod intercept is the difference between stadia readings
Estimated
distance
Stadia multiplier typically = 100
Indicated on inside of instrument case or in Instructional ManualSlide26
Stadia Readings
Upper Stadia Reading = 5.30 ft
Lower Stadia Reading = 5.20 ft
Rod Intercept =
0.10 ftSlide27
Stadia Reading
Rod Reading = 5.06 ft
Lower Stadia = 4.99 ft
Upper Stadia = 5.13 ft Slide28
Read the RodSlide29
Instrument
Point of Unknown Elevation
Differential Leveling
The establishment of differences in elevation between two or more points with respect to a datum
BM
Rod
RodSlide30
Differential Leveling
Start with point of known elevation
Benchmark (BM)
Point of Reference (POR)
Rod reading
7.59 ft (BS)
7.59 ft
Sight to rod on BM
Backsight (BS)
Height of Instrument (HI)
HI = BM elev + BS
HI = 350.00 + 7.59 = 357.59 ft
357.59 ft (HI)
357.59 ftSlide31
Field Notes
AUTO LEVEL
READINGS
STADIA
PT
(+)
BS
HI
(-)
FS
ELEV
TOP/BOT STADIA
DIST
/
Angle
BM
350.00
7.59
357.59
7.85 / 7.33
52 ftSlide32
Differential Leveling
Without moving the tripod,
Sight to rod on point of unknown elevation
Foresight (FS)
Identify elevation of point
Elev.
355.23 ft
Rod reading
2.36 ft (FS)
2.36 ft
Point of Interest
Elev
= HI - FS
Elev
= 357.59 – 2.36 = 355.23 ftSlide33
Field Notes
AUTO LEVEL
READINGS
STADIA
PT
(+)
BS
HI
(-)
FS
ELEV
TOP/BOT STADIA
DIST
/
Angle
BM
7.59
357.59
350.00
7.85 / 7.33
52
ft
x
PT- A
2.36
355.23
2.54 / 2.19
35 ftSlide34
Differential Leveling
2.36 ft (FS)
7.59 ft (BS)Slide35
Differential Leveling
Elev. 350.00 ftSlide36
Field Notes
AUTO LEVEL
READINGS
STADIA
PT
(+)
BS
HI
(-)
FS
ELEV
TOP/BOT STADIA
DIST
/
Angle
BM
7.59
357.59
350.00
7.85 / 7.33
52
ft
PT-A
2.36
355.23
2.54 / 2.19
35
ft
x
PT- B
4.17
353.42
PT-C
12.91
344.68
4.40 / 3.93
47 ft
13.21 / 12.61
60 ftSlide37
Image Sources
Sanford, F. (2006).
Seminole County geodetic control points
. Seminole County, Florida: Department of Public Works.
United States Geological Survey (USGS)
National Oceanographic and Atmospheric Administration Photo Library
http://www.photolib.noaa.gov/cgs/marks1.html
Istockphoto.com