Surveying (Finals Concepts and Terms) Flashcards
It is a series of consecutive lines whose ends have been marked in the field and whose lengths and direction have been determined from observations
traverse
It provides checks on the observed angles and distances, which is an extremely important consideration. They are used extensively in control, construction, property, and topographic surveys.
closed traverse
It consists of a series of lines that are connected but do not return to the starting point or close upon a point of equal or greater order accuracy.
open traverse
It is the part of the theodolite used to adjust the position of the telescope, may it be horizontally or vertically, to allow accurate measurements
leveling screws
if the bearing angle of a certain line comes from the north-south meridian, it is the value of the length of the line multiplied by the sine of the bearing angle
departure
What are the two conditions needed for a traverse to be considered close?
Sum of North and South Bearing are Eaqual
It is the value obtained by dividing the linear error of closure to the sum of all the lengths of a certain traverse
error of closure
He is an American navigator credited for he development of the Compass Rule
Prince Henry
it is distance (parallel to the east-west direction) from the midpoint of the line to the reference meridian
meridian
This method of calculating the area with irregular boundaries is only applicable for odd number of offsets
simpson’s rule or prismoidal rule
Areas with irregular boundaries need to be divided into this shape before proceeding with the calculations
triangles
It is the relationship between the distance between any two points on the map and its corresponding distance on the ground
map scale
this can be expressed as a ratio where 1 unit on the map corresponds to a certain number of the units on the ground
representative factor
These are maps having contour intervals of 5 to 2000 meters with scale smaller than 1:10000
small-scale maps
This represents the planimetric locations of the traces of level surfaces for different elevations
topographic map
This uses a symbol wherein ticks are drawn perpendicular to the contour line to identify the low spots such as excavations.
depression contours
Three methods to calculate the area with irregular boundaries
trapezoidal rule
simpson’s 1/3 rule
application of contours
elevation estimation- linear interpolation
reservoir capacity estimation - volume
flood -zone maps - overflows
intervisibility between points - profiles
A map portrays three kinds of information about geographic features:
- location and extent of the feature
- attribute (characteristics) of the feature
- relationship of the feature to other features
vary from 0 to 360
azimuths
require only numerical value
azimuths
may be geodetic, astronomic, magnetic, grid, assumed, forward or back
azimuths
are measured clockwise only
azimuths
are measured either from north only, or from south only on a particular survey
azimuths
vary from 0 to 90
bearings
require two letters and a numerical value
bearings
area measured clockwise and counterclockwise
bearings
area measured from north and south
bearings
It can be measured either clockwise or counterclockwise direction, but commonly prefer clockwise measurement
interior angle traverse
It is reduced in reading, plotting, and recording if one method of measurement is constantly adopted
error
the measurement of azimuth angles is by far one of the quickest and most satisfactory method where at one setup of the transit or theodolite several angles or directions can be determined
azimuth traverse
It is designed to accomplish the same primary purpose of the transit, to measure both vertical and horizontal angle measurements
theodolite
It is a line connecting points of equal elevations
contour
it is simply a horizontal that passes through points of equal elevation on a map
contour line
they are drawn on the paper to give the impression of a third dimension that shows hill, and valleys, as well as steep or gentle slopes
contour line
these heavier lines which are normally twice the gauge of the standard contours
index contours
they usually drawn every fifth contour and carry the contour number or elevation designation
index contours
the four lighter weight contours found between the index contours
intermediate contours
these lines are not usually labeled except where the terrain is relatively flat and their elevation are not readily obvious
intermediate contours
In certain portions of the map where the intermediate contours are so closely spaced as to nearly unite or merge into a single line, it is standard practice for readability not to portray the lines for short distances.
feathering
are employed where high accuracy is desired in locating contour lines.
arithmetical computations
This method is well suited for drawing large-scale maps.
analytical method
is based on the principle that the ratio of the horizontal length of a line to the difference in elevation between its 0extremities is the same ratio of the horizontal distance between either extremity and any intermediate point on the line to the difference in elevation between the selected extremity and the intermediate point.
analytical method
the most common method of expressing slope
percent or grade
arctan (DE/HD)
degrees
is determined by dividing the difference in elevation by the horizontal distance and expressing the numerator as one unit.
gradient
is another method of expressing slope and is commonly used by the military for expressing slope for computing field artillery firing data, sketching, and in reconnaissance surveys.
mils
unit of angular measurement based on the centesimal system.
grads
