2. Surveying
“Surveying is the art of determining the positions of points on or near the
Earth’s surface by means of measurements in the three elements of space;
namely, distance, direction, and elevation.” – Rayner & Schmidt.
3. Classification of Surveying
• Plane Surveying – is the type of surveying in which the earth is considered to be a
flat surface, and where distances and areas involved are of limited extent that the
exact shape of the Earth is disregarded.
• Geodetic Surveying – these are surveys of wide extent which take into account
the spheroidal shape of the earth.
4. TYPES OF SURVEYS
Cadastral Surveys – are usually closed surveys which are undertaken in
urban and rural locations for the purpose of determining and defining
property lines and boundaries, corners, and areas.
5. City Surveys – are surveys of the areas in and near a city for the
purpose of planning expansion or improvements, locating property
lines, fixing reference monuments, determining the physical features
and configuration of the land, and preparing maps.
6. Construction Surveys – these are surveys which are undertaken at a
construction site to provide data regarding grades, reference lines,
dimensions, ground configuration, and the location and elevation of
structure which are of concern to engineers, architects, and builders.
7. Forestry Surveys – a type of survey executed in connection with forest
management and mensuration, and the production and conservation
of forest lands.
8. Hydrographic Surveys – refers to the surveying streams, lakes,
reservoirs, harbors, oceans, and other bodies of water. These surveys
are made to map shore lines, chart the shape of areas underlying water
surfaces, and measure the flow of streams.
9. Industrial Surveys – sometimes known as optical tooling. It refers to
the use of surveying techniques in ship building, construction and
assembly of aircraft, lay-out and installation of heavy and complex
machinery, and in other industries where very accurate dimensional
layouts are required.
10. Mine Surveys – are surveys which are performed to determine the
position of all underground excavations and surface mine structures, to
fix surface boundaries of mining claims, determine geological
formations, to calculate excavated volumes, and establish lines and
grades for other related mining work.
11. Photogrammetric Surveys – a type of survey which makes use of
photographs taken with specially designed cameras either from
airplanes or ground stations. Measurements are obtained from the
photographs which are used in conjunction with limited ground
surveys.
12. Route Surveys – involves the determination of alignment, grades,
earthwork quantities, location of natural and artificial objects in
connection with the planning, design, and construction of highways,
railroads, pipelines, canals, transmission lines, and other linear
projects.
13. Topographic Surveys – are those surveys made for determining the
shape of the ground, and the location and elevation of natural and
artificial features upon it.
14. Surveying Tools & Instruments
Steel Tape – A steel measuring tape is a flexible ruler used to measure
linear distance.
15. Chaining Pins – are sometimes called taping (or surveyor’s) arrow. They
are used for marking the ends of tape or intermediate points during
taping.
16. Range Poles – sometimes called flags or lining rods, are used as guides
or markers when sighting points.
17. Transit – used for measuring horizontal angles and directions, vertical
angles, and differences in elevations, and for measuring distances.
18. Automatic Level - used for measuring horizontal angles and directions,
differences in elevations, and for measuring distances.
19. Theodolite – a theodolite is a precision optical instrument for
measuring angles between designated visible points in the horizontal
and vertical planes.
20. Leveling Rod – are used in conjunction with an instrument such as a
transit or level to determine distances or differences in elevation.
21. Total Station – is an electronic/optical instrument used in modern
surveying and building construction that uses electronic transit
theodolite in conjunction with electronic distance meter (EDM). It is
also integrated with microprocessor, electronic data collector and
storage system.
22. Reflectors & Targets – a device used with an EDM instrument when a
continuous beam of light needs to be transmitted during the
measurement of distances.
23. Tripod – a surveyor’s tripod is a device used to support to any one of
surveying instruments, such as, theodolites, total stations, levels or
transits.
24. Plumb Bob – a plumb bob, plumb bob level, or plummet, is a weight,
usually with a pointed tip on the bottom, suspended from a string and
used as a vertical reference line, or plumb line.
25. THE FIELD SURVEY PARTY
Chief of Party – the person who is responsible for the overall direction,
supervision, and operational control of the survey party.
Assistant Chief of Party – the person whose duty is to assist the chief
of party in the accomplishment of the task assigned to the survey party
Instrumentman - the person whose duty is to set up, level, and
operate surveying instruments.
26. Technician – the person who is responsible for use and operation of all
electronic instruments required in a field work operation.
Computer – the person whose duty is to perform all computations of
survey data and works out necessary computational checks required in
a field work operation.
Recorder – the person whose duty is to keep a record of all sketches,
drawings, measurements and observations taken or needed for a field
work operation.
27. Head Tapeman – the person responsible for the accuracy and speed of
all linear measurements with tape.
Rear Tapeman – the person whose duty is to assist the head tapeman
during taping operations and in other related work.
Flagman – the person whose duty is to hold the flagpole or range pole
at selected points as directed by the instrumentman. He helps the
tapeman in taking the measurements.
Rodman – the person whose primary duty is to hold the leveling rod
when sights are to be taken on it.
28. Pacer – the person whose duty is to check all linear measurements
made by the tapeman. He assists the tapeman in seeing to it that
mistakes and blunders in linear measurement are either reduced or
eliminated.
Axeman/Lineman – the person whose duty is to clear the line of sight
of trees, brush, and other obstructions.
Utilitymen – the person whose duties are to render other forms of
assistance needed by the survey party or as directed by the chief of
party.
29. SURVEYING FIELD NOTES
Types of notes:
• Sketches
• Tabulations
• Explanatory Notes
• Computations
• Combination of the above
30.
31. Surveying Measurements
• Direct Measurements – Example (applying a tape to a line,
determining a horizontal or vertical angle with a transit, etc)
• Indirect Measurements – (improvised measuring using the
knowledge of trigonometry or geometry, etc)
32. Units of Measurements
Linear & Area Measurements
1 kilometer (km) = 1 000 meters
1 meter (m) = 1 000 millimeters
1 meter (m) = 10 decimeters
1 decimeter (dm) = 10 centimeters
1 centimeter (cm) = 10 millimeters
1 hectare (ha) = 10 000 square meters
Angular Measurements
2π radian = 360 degrees 0 minutes 0 seconds
33. TYPES OF ERRORS
1. Systematic Error – are errors caused by the surveying equipment,
observation methods, and certain environmental factors.
Example:
Errors in taping due to ambient temperature
34. 2. Accidental or Random Errors – accidental or random errors are
unpredictable and are often caused by the factors beyond the control
of the surveyor.
Example:
The instrumentman accidentally read the upper stadia hair instead of
the middle cross hair
35. Sources of Errors
1. Instrumental Errors – this source of error are caused by imperfectly
constructed, adjusted, or calibrated surveying equipment.
2. Natural Errors – this source of error are caused by environmental
conditions or significant changes in environmental conditions
3. Personal Errors – human errors are caused by physical limitations
and inconsistent setup and observation habits of the surveyor.
36. The Most Probable Value
Since the true value is theoretically never known, we refer to the Most
Probable Value as our “true value”
mpv = x̄ = ∑x/n = (𝑥1 + 𝑥2 + 𝑥3 + . . . +𝑥𝑛) / n
37. A surveying instructor sent out six groups of students to measure a
distance between two points marked on the ground. The students
came up with the following six different values: 250.25, 250.15, 249.90,
251.04, 250.50, and 251.22 meters. Assuming these values are equally
reliable and that variations result from accidental errors, determine the
most probable value of the distance measured.
38. The angles about a point Q have the following observed values. 130°
15’ 20”, 142° 37’ 30”, 87° 07’ 40”. Determine the most probable value
of each angle.
Given:
θ1 = 130° 15’ 20”
θ2 = 142° 37’ 30”
θ3 = 87° 07’ 40”
θ1
θ2
θ3