DEFINITIONS OF SURVEYING
DEFINITIONS OF SURVEYING
In general, surveying is performed to determine
the relative location or positioning of points on or near the earth's surface.
More specifically, surveying is the science of making
measurements, relative to known or assumed datum’s and standards, and applying
the principles of mathematics to such measurements to determine existing or
future horizontal and vertical position, from area, magnitude, boundaries, and extent
of land parcels and topographical features.
Surveying
or land surveying
is the
technique and science of accurately determining the terrestrial or
three-dimensional position of points and the distances and angles between them.
These
points are usually on the surface of the Earth, and they are
often used to establish land maps and boundaries for ownership or
governmental purposes
American
Congress on Surveying and Mapping (ACSM)
Provide
an alternative definition of surveying as the science and art of making all
essential measurements to determine the relative position of points and/or
physical and cultural details above, on, or beneath the surface of the Earth,
and to depict them in a usable form, or to establish the position of points
and/or details.
"Land
surveying" (also per ACSM)
Is
the detailed study or inspection, as by gathering information through
observations, measurements in the field, questionnaires, or research of legal
instruments, and data analysis in the support of planning, designing, and
establishing of property boundaries?
Categories
of surveying
Surveying encompasses the following categories:
1.
Geodetic Surveys –
Surveys, which establish control networks on a
mathematical datum so that measurements will reflect the curved (ellipsoidal)
shape of the earth.
2.
Land Surveys –
Surveys which include retracement of existing
land ownership boundaries or the creation of new boundaries.
3.
Engineering Surveys –
Surveys performed for the location, design,
construction, maintenance and
operation of engineering projects.
4.
Construction Surveys –
Surveys which establish stakes in the ground, and
other like reference points, at known horizontal and vertical positions to
define location and size of each component of the facility to be constructed,
enable inspection of contract items, and serve as a basis of payment for work.
5.
Cartographic Surveys –
Map making from original surveys.
B. IMPORTANCE OF SURVEYING
1. The
Basic Engineering Discipline –
Surveying is basic to all civil engineering
works. In transportation
Engineering, surveying provides the foundation
and continuity for route location, design, land acquisition, and all other
preliminary engineering.
Surveys also set a basic "framework" of
stakes, which is used by contractors and engineers in building and inspecting
transportation projects.
2. The
Thread of Continuity –
Surveying is the single engineering function
which links all the phases of a project including conception, planning design,
land acquisition, construction and final monumentation.
3.
Basis for Efficiency –
To a
great degree, the acceptability and cost-effectiveness of planning, land
acquisition, design, and construction are
dependent upon properly performed surveys.
Types
of surveys and applicability
ALTA/ACSM Survey: a surveying standard jointly
proposed by the American Land Title Association and
the American Congress on
Surveying and Mapping that incorporates elements of the boundary survey,
mortgage survey, and topographic survey.
Is used to accurately assess the relationship of
archaeological sites in a landscape or to accurately record finds on an
archaeological site.
As-built
survey:
a survey carried out during or immediately after a
construction project for record, completion evaluation and payment purposes.
a survey carried out to map the topography and features
of the bed of an ocean, lake, river or other body of water.
Boundary
survey:
a survey that establishes boundaries of a parcel using
its legal description, which typically involves the
setting or restoration of monuments or markers at the corners or along the
lines of the parcel, often in the form of iron rods,
pipes, or concrete
monuments in the ground, or nails
set in concrete or asphalt.
a survey to determine if a structure or object is
changing shape or moving. The three-dimensional positions of specific points on
an object are determined, a period of time is allowed to pass, these positions
are then re-measured and calculated, and a comparison between the two sets of
positions is made.
Engineering
surveys:
Those surveys associated with the engineering design
(topographic, layout and as-built) often requiring geodetic computations beyond
normal civil engineering practise.
Foundation
survey:
a survey done to collect the positional data on a
foundation that has been poured and is cured. This is done to ensure that the
foundation was constructed in the location, and at the elevation, authorized in the plot
plan, site plan, or subdivision plan.
Geological
survey:
generic term for a survey conducted for the
purpose of recording the geologically significant features of the area under
investigation. .
Hydrographic
survey:
a
survey conducted with the purpose of mapping the coastline and seabed for
navigation, engineering, or resource management purposes.
Measured
survey:
a
building survey to produce plans of the building. such a survey may be
conducted before renovation works, for commercial purpose, or at end of the
construction process "as built survey"
Mortgage
survey or physical survey:
a
simple survey that delineates land boundaries and building locations. In many
places a mortgage survey is required by lending institutions as a precondition
for a mortgage loan.
Soil
survey,
or soil mapping, is the process of determining the soil
types or other properties of the soil cover over a landscape, and mapping them
for others to understand and use.
Structural
survey:
A detailed inspection to report upon the physical
condition and structural stability of a building or other structure and to
highlight any work needed to maintain it in good repair.
Tape
survey:
This type of survey is the most basic and inexpensive
type of land survey. Popular in the middle part of the 20th century, tape
surveys while being accurate for distance lack substantially in their accuracy
of measuring angle and bearing. Standards that are practiced by professional
land surveyors.
Topographic
survey:
a
survey that measures the elevation of points on a particular piece of land, and
presents them as contour lines on a plot.
Classification of Surveys according to the field of work | Surveying and Levelling
In one of my previous articles regarding “Classification
of Surveys“, discussion of various types of surveys have been listed out.
We are now proceeding with the detail study of different types of surveys under
the category of field of work.
The classification for the field of work is as follows:
Land Survey
This involved survey of objects in earth’s
surface.
German Soldier carrying out Land Survey to determine
the natural features and determine areas of strategic importance
Hydrographic or Marine Survey
This involves survey of objects under water.
Marine Survey
Aerial Survey
Aerial survey is carried out by an aeroplane in
air.
Land Survey can be further classified into the following:
- Topographical survey
- Cadastral Survey
- City Survey
- Engineering Survey
Topographical Survey
This survey is performed or determining the
natural features of the country such as rivers, mountains, hills, valleys etc.
and also artificial features such as canals, railways, roads, towns, villages
etc.
This helps to keep a record of existing natural
features of the country.
Cadastral Survey
Cadastral Survey is similar to topographical
survey. It only involves a little more precision and detailing in the process.
Apart from determining the natural features, this method of survey also helps
to determine boundaries of fields, houses and other properties.
Cadastral Survey maps are drawn to a more larger
scale as compared to topographical survey maps.
This is performed in connection with town
planning schemes such as drainage, water supply etc and for laying plots,
roads, streets etc.
City Survey
City Survey is carried out in connection with
various engineering works such as roads, railways etc and it also involves
various works related to water supply sector such as reservoirs, wells etc.
Engineering Survey
Engineering Survey is further classified into the following three types:
- Reconnaissance Survey
- Preliminary Survey
- Location Survey
Reconnaissance Survey
This survey is performed for determining the feasibility
of work and to estimate the rough cost of the scheme.
Preliminary Survey
This survey is performed for collecting more
précised data to choose the best location for the work and to estimate the
exact quantities and cost.
Location Survey
This survey is performed for setting out the work
on the ground.
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