FUNDAMENTALS OF
SURVEYING
Topic Outline
1. Introduction to Levelling
2. Differential Levelling
3. Profile Levelling
Intended Learning Outcomes
The student will be able to:
1.
Explain the basic concepts of levelling
operations in Surveying
Intended Learning Outcomes
The student will be able to:
2.
Discuss the various techniques in levelling
Intended Learning Outcomes
The student will be able to:
3.
Measure actual elevations using various
surveying instruments
Assessment Tasks
Module Activities
Quiz
DISTANCE
MEASUREMENT
VERTICAL DISTANCE
MEASUREMENT
Elevation
the vertical distance of a point above or
below a given reference surface
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Elevation
most commonly used reference
mean sea level (msl)
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Leveling
the process of determining the elevation
of various points on an area/ground
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Leveling
barometric
trigonometric
differential
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Barometric Leveling
uses special barometers (altimeters) to
measure air pressure the elevation of
points on the earth’s surface
(air pressure decreases
with increasing elevation)
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Trigonometric Leveling
indirect procedure
the vertical distances are computed from
vertical angles and horizontal/slope
distances
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Differential Leveling
most common levelling method
aligns the telescopic sight in a horizontal
direction in a direction perpendicular to
the vertical direction/axis
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
an instrument which establishes
a horizontal line of sight
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
telescope
spirit bubble vial
levelling head
portion of the level with 3-levelling screws
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
telescope components:
reticle
provides the cross-hairs near the rear
of the telescope tube
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
telescope components:
eyepiece
magnifies the crosshairs
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
telescope components:
objective lens
forms an image of the sighted target
within the telescope tube
located at the forward end
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level
telescope components:
focusing lens
can be moved back and forth inside
the scope to focus the image
on the crosshairs
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Tripod
a stand in which the level
is securely mounted
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Level/Leveling Rod
a graduated rod held vertically
at a specific location or point
on the ground which is read for
its vertical distances
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Study Task:
Hand Signals in Survey
What are the typical
hand signals/gestures
used during survey operations?
Vertical Distance Measurement: Differential Leveling
Basic Operations
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Obtaining HI from BS at BM
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Backsight (BS)
the rod reading on a point
of known elevation
plus sight (+S) reading
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Height of Instrument (HI)
the elevation of the horizontal line of sight
through the level
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Obtaining HI from BS at BM
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Obtaining elev from FS at TP
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Foresight (FS)
the rod reading on a point
of unknown elevation
minus sight (-S) reading
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement: Differential Leveling
Elevation
subtract the FS reading
from the calculated HI
HI should not change when the level’s
telescope is rotated from BS to FS
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Reciprocal Leveling
used when it is necessary to run levels
accurately over surfaces with obstructions
i.e. rivers, ponds
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Reciprocal Leveling
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Profile Leveling
the process of determining the elevations
of a series of points on the ground
at mostly uniform intervals
along a continuous line
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Profile Leveling
profile
a drawing that shows a vertical section or
side view of the earth surface
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Profile Leveling
several additional FS readings may be
taken on as many points as desired
rod shots
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Profile Leveling
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Profile Leveling
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Trigonometric Leveling
the difference in elevation between
two points is indirectly obtained
by measuring a vertical or zenith angle
and the horizontal or slope distance
between the points
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Trigonometric Leveling
vertical distance is computed using
right-angle trigonometric formulas
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Trigonometric Leveling
electronic distance measurement (EDM)
used to increase the accuracy and speed
in trigonometric levelling
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
Vertical Distance Measurement:
Trigonometric Leveling
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011). Surveying
fundamentals and practice. Pearson Education, Inc.
References
Kavanagh, B., Mastin, T. (2014).
Surveying: principles and applications.
Pearson Education, Inc.
Nathanson, J., Kissam, P., Lanzafama, M.T. (2011).
Surveying fundamentals and practice.
Pearson Education, Inc.
