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Surveying

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					                      Surveying
I. *Special Terms
1. Surveying: measuring, and recording by means of
     maps, the earth’s surface with the greatest degree
     of accuracy possible. Or: the practice of taking
     measurements of features on, and occasionally
     above or below, the earth’s surface to determine
     their relative positions.
2. Horizontal Plane: Perpendicular to the force of
     gravity.
3. Vertical Plane: In line with the direction of gravity.
4. Plumb Bob: Lead weights attached to a line to
     show the direction of gravity.
5. Tripod: a stand with three legs.

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                  Surveying
I. Special Terms
6. Chain: A device 66 feet long (surveyor's chain)
     or 100 feet long (engineer's chain) for measuring
     distance. Breaking Chain: Measuring distance
     with less than the full length of the tape.
7. Transit: A telescopic device that can be used for
     measuring distances and horizontal and vertical
     angles.
8. Theodolite: A special kind of transit that gives
     more accurate readings of angles than a
     standard transit.
9. Stadia Hairs: Lines in a transit that are used in
     determining distance. “Stadia” is the plural of
     stadium, a Greek word for a measure of distance,
     about 607 feet.
                   Surveying
I. Special Terms
11. Plane-table Alidade: a kind of telescope to
     measure both distances and vertical angles. It is
     set on a plane table (a flat table), which a
     surveyor can use as a drawing board to make
     maps in the field.
12. Contour Lines: The lines on a map that indicate
     points of equal elevations (heights).
13. Surveyor's Level: a kind of telescope with a
     bubble level, a tube of fluid with an air bubble in
     it. The surveyor can sight a level rod though the
     telescope in order to measure elevation.
14. Bench Mark: A point whose elevation has been
     previously determined and marked. It is used as
     a basis for additional measurements.
                 Surveying
I. Special Terms
15. Altimeter: A device that measures elevation by
     means of atmospheric pressure.
16. Mosaic: In aerial surveying, an overlapping
     arrangement of photographs that eliminates
     distortion at the edges of the pictures.
17. Triangulation: In geodetic surveying, measuring
     a network of triangles based on points on the
     earth's surface.
18. Geological Survey: Determining underground
     conditions, such as types of soil and rock
     beneath the surface.
19. Boring: The process of bringing up samples of
     subsurface soil and rock by means of a hollow
     drill. Each sample is also called a boring.
                    Surveying
I. Special Terms
20. Gravimeter: A device that measures the earth's
     gravitational pull.
21. Magnetometer: A device that measures the
     strength of the earth's magnetism.
22. Seismograph: A device that measurer the
     strength of vibrations (seismic waves) within the
     earth.
II. *Types of Surveying: plane and geodetic
1. Plane surveying is the measurement of the earth’s
     surface without considering its curvature. Within
     areas of about 20 km2, the earth’s curvature does
     not produce any significance errors in a plane
     survey.
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                   Surveying
2. Geodetic surveying is the kind of surveying
     which accounts for the earth’s curvature, usu.
     made over large areas.
III. Purposes of surveying: determine the best and
     most economical location or route.
IV. *Contents of surveying: distances, elevations
     (height differences), angles, boundaries, and
     other physical characteristics of the site. (cf.
     physical conditions vs physical properties)
V.   Device for measuring distance in plane
     surveying: steel tape and chain
VI. *Temperature factor in readings: The indicated
     length of a steel tape is in fact exactly accurate
     only at a temperature of 20 degrees centigrade.
VII. Exercises (due Wednesday, Week 3)
                    Surveying
VII. Prefixes indicating numerals:
1.    Demi- half e.g., demigod, demilune
2.    Hemi- half e.g., hemicycle, hemisphere
3.    Semi- half e.g., semiconductor, semifinal
4.    Mono- one, e.g., monotonous, monograph
5.    Uni- one , e.g., uniform, unite, unique
6.    Bi- & di- two, e.g., dioxide, dialogue
7.    Ambi-, amphi- two, e.g., ambiguous, amphibian
8.    Du- double, two, e.g., dual, duetto
9.     tri- trigonometry, trilogy
10. Quadri- & tetra- four e.g., quadrilateral,
      tetralogy
11. Penta- pentagon, pentachloride
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                    Surveying
III. Prefixes indicating numerals:
12. Quin- five e.g., quintet, quintuplet
13. Hexa- & sex- e.g., hexahedron, sexennial,
      sextuple, sexagesimal
14. Hepta- & sept- e.g., heptagon,
      septavalent(septivalent), September
15. Oct- e.g., October, octopus
16. Ennea- & nona- e.g., enneagon, nonagon
17. Deca- & deci- e.g., decade, decagon, decimal,
      December



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posted:3/14/2013
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