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PSA/ZAR/DKA_CC103/TOPIC_1 PAGE 1
TOPIC 1 (INTRODUCTION)
COURSE LEARNING OUTCOME
- Describe briefly types of surveying
1.0 INTRODUCTION
Definition:
Is a science and art of measuring, recording and drawing to scale, the location, the
size and shape of natural and man-made features on a surface of the earth.
Determine the relative position of distinctive features on the surface/beneath the
surface of earth, by means of measurement of distance, direction and elevation
Surveying can be defined as the art and science of making measurements of the
relative positions of natural and manmade features on the earth’s surface, and
presentation of this information either graphically (in the form of a map or plan) or
numerically.
Basically, surveying is a process of measuring distance, height differences and angles
at construction site
1.1 PURPOSE OF SURVEYING
The main purpose of surveying work is to obtain data of the earth surface to:
Produce plan, cross and longitudinal sections of proposed project area to be built.
Determine boundary and area of site to determine ownership and permission to enter
the site.
Determine volume of soil that may be required during construction.
Ensure the project to be constructed is in the correct position.
Obtain soil profile of the area and later, to determine the required cut and fill.
Determine the site level as well as the location of construction such as gradient of
drainage and others.
Record the final location of construction including any adjustment to it.
PSA/ZAR/DKA_CC103/TOPIC_1 PAGE 2
1.2 PRIMARY DIVISIONS OF SURVEYING
Can be devided into two groups which are:-
1.2.1 Plane Surveying
Which the mean surface of earth is regarded as plane survey and not curved
as it really is.
Survey area cover up to 260sq. Km
Used for layout of highways, railways, canals, tunnel, fixing boundary pillars,
construction, construction of bridges and factories.
1.2.2 Geodetic survey
Curvature of the earth is taken into account.
Demand higher degree of accuracy in linear as well as angular observations is
achieved.
1.3 CLASSIFICATION OF SURVEY
Classification can be done based on its use and also purpose of survey
1.3.1 Classification based upon the nature of the fields
a. TOPOGRAPHIC SURVEY
Depict the topography of the mountainous terrain, rivers, water bodies,
wooded areas and other cultural details such as roads, railways,
townships etc.
b. CADASTRAL SURVEY
Carried out for fixing the property lines, calculation area of landed
property and preparation of revenue maps of state.
c. CITY SURVEY
Carried out for the construction of roads, parks, water supply system,
sewer and other constructional work for any developing township.
PSA/ZAR/DKA_CC103/TOPIC_1 PAGE 3
d. HYDROGRAPHIC SURVEY
Mapping of large water bodies for the purpose of navigation,
construction of harbour work, prediction of tides and determination of
mean sea level.
Consist of preparation of topographical maps of the shores and banks,
by taking sounding and determining the depths of water at a number of
places.
e. ASTRONOMICAL SURVEY
Carried out to determine absolute location e.g. latitude of different
places on the earth surface and the direction of any line on the surface
of the earth by making observations to heavenly bodies.
1.3.2 Classification based on the purpose of survey
a. ENGINEERING SURVEY
Determine of quantities on to afford sufficient data for designing
engineering works such as roads, sewage disposal and water supply.
b. MILITARY/ DEFENCE SURVEY
Preparation of maps of the areas of military importance
c. MINE SURVEY
Exploration of mineral wealth’s beneath the surface of the ground
d. GEOLOGICAL SURVEY
To ascertain the composition of the earth crust
e. ARCHAEOLOGICAL SURVEY
To prepare maps of ancient culture.
1.3.3 Classification based on instrument used
a. Chain survey
b. Compass survey
PSA/ZAR/DKA_CC103/TOPIC_1 PAGE 4
c. Plane table survey
d. Theodolite survey
e. Tacheometric survey
f. Photogrammetric survey
1.4 BASIC PRINCIPLES
Measure distance
Measure distance at right angles
Measure distance and angle
Measure angles
The fundamental rule in surveying project is WORK FROM THE WHOLE TO THE
PART.
1.5 THE STAGES OF SURVEY OPERATION
The entire work may be devided into three stages:-
1.5.1 Field work
Consist of measurement of distance and angles required for plotting to scale and
keep systematic record in the form or field book
a. Reconnaissance - the surveyor goes over the area to fix a number of
stations to ensure intervisibility.
b. Observation – also includes determination of difference in elevations
between the stations and surveying contours of land areas and
bathymetric contours of water bodies.
c. Field records - all the measurements are recorded in the field book.
1.5.2 OFFICE WORK
The field notes are brought to the office and necessary drafting, computing and
designing work are done by draftsmen and computer.
PSA/ZAR/DKA_CC103/TOPIC_1 PAGE 5
1.5.3 CARE & ADJUSTMENTS OF INSTRUMENTS
A great care is required to handle survey instruments. A beginner should always
be made familiar with care and adjustments of the instruments and its limitations.
1.6 UNDERSTANDING MAP AND PLAN
1.6.1 Plan – will accurately define widths of roads, size of building etc. every
features are exactly true to scale
1.6.2 Map – Is a representation, no matter how accurately it may be shown.
1.7 ERROR
Every measurement contains errors of unknown magnitude due to several
reasons and hence no measurement in surveying is exact.
1.7.1 SOURCES OF ERRORS
a. Natural errors: - Result from the temperature, refraction, obstacles to
measurement, magnetic declination
b. Instrumental errors:- Result from the imperfect construction and adjustment of
the instrument
c. Personal errors:- Arise from the limitation of the human senses such as sight,
touch and hearing
1.7.2 TYPES OF ERRORS
a. Systematic errors:- Errors which occur from well understood causes.
b. Accidental errors:- Due to combination of cause and are beyond the control of
surveyor
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