Surveying Final

backsight

a sight taken with a level to a point of known elevation, thus permitting the surveyor to compute the elevation of the HI, in transit work the backsight is a sighting taken to a point of known position to establish a reference direction

barrow pit

a source of fill material that is located off the right of way

geographic information system (GIS)

a spatially and relationally referenced data base

catch basin

a structure designed to collect surface water and transfer it to a storm sewer

culvert

a structure designed to provide an opening under a road etc, usually for the transportation of storm water

geoid surface

a surface that is approximately represented by mean sea level (MSL), and is in fact the equipotential surface of the earths gravity field

automatic level

a surveyors level whose line of sight is automatically maintained in the horizontal plane, once the instrument is roughly leveled

grade transfer

a technique of transferring cut/fill measurements to the facility, i.e carpenters level, stringline level, laser, and batter boards

double centering

a technique of turning angles or producing straight lines involving a minimum of two sightings with a theodolite: once with the telescope direct and once with the telescope inverted

interlining

a trial and error technique of establishing a theodolite on a line between two points that themselves are not intervisible

gon

a unit of angular measure in which 1 revolution= 400 gon and 100 gon= a right angle, also known as grad

nadir angle

a vertical angle measured fromt he nadir direction (striaght down) upward to a point

grade stake

a wood stake with a cut/fill reference mark to that portion of a proposed facility adjacent to the stake

page check

arithmetic check

normal tension

the amount of tension required in taping to offset the effects of sag

deflection angle

the angle between the prolongation of the back line measured right (R) or left (L) to the forward line

azimuth

the angle to a line of sight, measured clockwise (usually) from a north meridian

latitude (of a course)

the change in northerly displacement of a line (Y)

drainage

the collection and transportation of ground and storm water

accuracy

the conformity of a measurement to the "true" value

clearing

the cutting and removal of trees from a construction site

geoid undulation

the difference between the geoid surface and the ellipsoid surface, N is negative if the geoid surface is below the ellipsoid surface

geodetic height

the distance from the ellipsoid surface to the ground surface

external distance

the distance from the mid-curve to the PI

mid-ordinate distance

the distance fromt he mid-chord to the mid-curve

coordinates

the distances measured north and east of a reference point having zero coordinates

accuracy ratio

the error in a measurement divided by the overall value of the masurement- expressed as a fraction with a numerator of 1 and a denominator rounded to the clsoest 100 units, example: an error of .01 ft in 30.00 ft would result in an accuracy ratio of 1/3000

elevation factor

the facor used to convert ground distances to sea-level distances

forced centering

the interchanging of theodolites, prisms, and targets into tribrachs- which are left in position over the station

polar coordinates

the location of a feature by angle and distance

alignment

the location of the center line of a survey or a facility

original ground

the position of the ground surface prior to construction

grubbing

the removal of stumps, roots etc from a construction site

gradient

the slope of a grade line

elevation

the vertical distance above or below a given datum; also known as orthometic height

hectare

10,000 square meters

arithmetic check

a check on the reductions of differential leveling involving the sums of the backsights and the foresights

skew number

a clockwise angle turned from the back tangent to the center line of a culvert or bridge

grade sheet

a construction report giving line and grade, i.e offsets, and cuts/fills at each station

traverse

a continuous series of measured (angle and distances) lines

free station

a conveniently locaated instrument station used for construction layout, the position of which is determined after occupation through resection techniques

circular curve

a curve with a constant radius

ground distance

a distance measured on the ground surface

grid distance

a distance on a coordinate grid

three-wire leveling

a more precise technique of differential leveling in which rod readings are taken at the stadia hairs in addition to the main cross hair

vertical curve

a parabolic curve joining two grade lines

station

a point on a baseline that is a specified distance fromt he point of commencement. the oint of commencement is identified as 0+00; 100 feet or 100 meters are known as full stations; 1+45.20 identifies a point distance 145.2 ft from the point of commencement

pre-engineering survey

a preliminary survey that forms the basis for engineerign design

intermediate sight

a sight taken with a level or transit to determine its elevation and or location

tangent

a straight line, often referred to with respect to a curve

property survey

a survey to retrace or establish propery lines or to establish the location of buildings within property limits

avulsion

a tearing away

spiral curve

a transition curve of constantly changing radius placed between a high-speed tangent and a central curve; it permits a gradual speed adjustment

zenith angle

a vertical angle measured downward fromt he zenith (upward plumbline) direction

orthometic height

also known as elevation, the distance from the geoid surface to the ground surface

vertical angle

an agnle in the vertical plane measure up (+) or down (-) from horizontal

datum

an assumed for fixed horizontal reference plane

data collector

an electronic field book designed to store field data- both measured and descriptive

total station

an electronic theodolite combined with an EDM and an electronic data collector

parallax

an error in sighting that occurs when the objective and or the cross hairs of a telescope are improperly focused

accretion

an increase by natural growth or by gradual external addition; growth in size or extent

shaft

an opening of uniform cross section joining a tunnel to the surface; used for access and ventilation

latitude (geographic)

angular distance from the earths center measured northerly or southerly from the equatorial plane

longitude

angular distance measured in the plane of the equator from the reference meridian through Greenwich, England. lines of longitude are indicated on globes as meridians

toe of slope

bottom of slope

layout survey

construction survey

COR

continuously operating receiver (GPS), its transmitted data can be used by single-receiver surveyors or navigators to permit higher precision differential positioning

differential leveling

determining the differences in elevation between points using a surveyors level

bearing

direction of a line given by the acute angle from a meridian and accompanied by a cardinal compass direction

gunters chain

early measuring device consisting of 100 links, measuring 66 ft long

EDM

electronic distance measurement

EFB

electronic field book (data collector)

GDOP

geometric dillution of precision: indicates the strength of figure of the satellite array as positioning signals are received

grad

gon

Hi

heigh of the line of sight of an instrument above a datum; used in leveling

hi

height of instrument (optical axis) above the instrument station; used in stadia, EDM, and GPS

laser alignment

horizontal and or vertical alignment given by a fixed or rotating laser

batter boards

horizontal cross pieces on grade stakes or grade rods that refer to proposed elevations

cut

in construction, the excavation of material; also the measurement down from a grade mark

haul

in highway construction, the distance that 1 cubic yard of cut material is transported to a fill location

turning point

in leveling, a solid point where an elevation is temporarily established so that the level may be relocated

fill

material used to raise the construction level; also the measurement up from a grade mark

universal time

mean solar time at the meridian of Greenwich, kept by atomic clocks

grid meridian

meridians paralllel to a central meridian on a coordinate grid

slope stakes

stakes placed to locate the top or bottom of a slope

hydrographic surveys

surveys designed to define shoreline and underwater features

superelevation

the banking of a curved section of road to help overcome the effects of centrifigal force

departure

the change in easterly displacement of a line (X)

precision

the degree of refinement with which a measurement is made

remote object elevation

the determination of the height of an object by a total station sighting

sag

the error caused when a tape is supported only at the ends

sea-level correction factor

the factor used to convert ground distances to sea-level equivalent distances

scale factor

the factor used to convert sea-level distances to plane grid distances

line and grade

the horizontal and vertical position of a facility

springline

the horizontal bisector of a pipe

invert

the inside bottom of a pipe or culvert

right of way

the legal limits of a utility or access route

linear error of closure

the line of traverse misclosure representing the resultant of the measuring errors

rectangular coordiatnes

the location fo a feature by two distances, 90 degrees opposed

adverse possession

the open and exclusive occupation and use of someone else's real property without permission of the owner continuously for a period of years prescribed by law, thereafter giving title o the occupier-user

waving the rod

the slight waving of the leveling rod to and from the instrument which permits the surveyor to take a precise (lowest) rod reading

resection

the solution of the coordiatnes of an occupied station by the sighting angles of three or more cooridated reference stations; two or more stations if both angels and distances are measured

common law

the system of law originating in england, as distinct from the civil or roman law and the canon or ecclesiastical law

sidereal day

the time taken for one complete revolution of the earth with reference to an infinitely faraway object eg a star

compound curve

two or more circular arcs turning in the same direction that have common tangent points and different radii

UTM

universal transervse mercator grid system

fiducial marks

reference marks on the edges of aerial photos, used to locate the principal point on the photo

differential GPS

GPS surveys in which one receiver occupies a position of know position while other receivers occupy points whose positions are to be determined

as-built (final) surveys

post-construction surveys that confirm design executions and record in-progress revisions

engineering surveys

preliminary and layout surveys used for design and construction

route survey

preliminary, control and construction surveys that cover a long but narrow area, as in highway and railroad construction

construction survey

provision of line and grade

mistake

a poor result due to carelessness or a misunderstanding

geodetic datum

a precisely established and maintained series of benchmarks referenced to adjusted Mean Seal Level (MSL)

cross section

a profile of the ground and surroundings taken at right angles to a reference line

mean sea level (MSL)

a reference datum for leveling

central meridian

a reference meridian in the center of the zone covered by the plane coordinate grid- at every 6 degrees of longitude in the UTM grid

local road (highway)

a road designed for property access, connected to arterials by collectors

arterial road (highway)

a road designed primarily for traffic mobility, with some property access consideration

collector road (highway)

a road designed to provide property access with some traffic mobility; it connects local roads to arterials

NAVSTAR

a set of orbiting satellites used in navigation and positioning

parabolic curve

a curve used in vertical alignment to join two adjacent grade lines

grid factor

a factor used to convert ground distances to grid distances

benchmark

a fixed solid reference point with a precisely determined published elevation

mass diagram

a graphic representation of cumulative highway cuts and fills

global positioning system (GPS)

a ground positioning (y,x, and z) technique based on the reception and analysis of NAVSTAR satellite signals

freeway

a highway designed for traffic mobility in which access is restricted to interchanges with arterials and other freeways

baseline

a line of reference for survey work; often the center line, street line, or the center line of construction is used, although any line could be arbitrarily selected or established

contour

a line on a map joining points of similar elevation

geographic meridian

a line on the surface of the earth joining the poles i.e a line of longitude

planimeter

a mechanical or electronic device used to measure areas by tracing the outline of the area on the map or plan

meridian

a north-south reference line

monument

a permanent reference point for horizontal and vertical positioning

plat

a plan of survey usually showing property information