history and some modern era with addition of some advance tools

1. Sandhu Engineering & Trading
Company
Water Management Training Institute

2. We are going to discus today!
• Survey!
• History
• Modern Era
• List of Surveying Instruments
• Dumpy Level
• Auto Level
• Digital Electronic Level
• Laser Level
• Leveling
• Theodolite
• Total Station
• GNSS
• The End
SETC 2

3. Surveying
• Its the technique, profession, art, and science of determining the
terrestrial or three-dimensional positions of points and the distances and
angles between them.
• Surveyors work with elements of geometry, trigonometry, regression
analysis, physics, engineering, metrology, programming languages, and
the law. They use equipment, such as total stations, robotic total
stations, theodolites, GNSS receivers, retro reflectors, 3D scanners,
radios, inclinometer, handheld tablets, digital levels, subsurface locators,
drones, GIS, and surveying software.
Surveying 3

4. • A surveyor is a professional person with the academic qualifications and
technical expertise to conduct one, or more, of the following activities;
• to determine, measure and represent land, three-dimensional objects,
point-fields and trajectories;
• to assemble and interpret land and geographically related information,
• to use that information for the planning and efficient administration of the
land, the sea and any structures thereon; and,
• to conduct research into the above practices and to develop them.
• Techniques
• Distance measurement
• Angle measurement
• Levelling
• Determining position
• Reference networks
• Datum and coordinate systems
• Errors and accuracy
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5. History
Ancient history
• Surveying has occurred since humans built the first large structures.
In ancient Egypt, a rope stretcher would use simple geometry to re-
establish boundaries after the annual floods of the Nile River. The
almost perfect squareness and north–south orientation of the Great
Pyramid of Giza.
• The Groma instrument originated in Mesopotamia (early 1st millennium
BC).
• The prehistoric monument at Stonehenge (c. 2500 BC) was set out
by prehistoric surveyors using peg and rope geometry.
• The Romans recognized land surveying as a profession.
• Roman surveyors were known as Gromatici.
History 5

6. Modern era
• The Level was used in early 16th Century, It enabled plots of land to be
accurately surveyed and plotted for legal and commercial purposes.
• In the 18th century, modern techniques and instruments for surveying began
to be used. Jesse Ramsden introduced the first precision theodolite in 1787.
It was an instrument for measuring angles in the horizontal and vertical
planes. He created his great theodolite using an accurate dividing engine of
his own design. Ramsden's theodolite represented a great step forward in the
instrument's accuracy.
Modern era 6

7. • At the beginning of the century surveyors had improved the older chains and ropes, but
still faced the problem of accurate measurement of long distances.
• The newly developed the Tellurometer during the 1950s allowed to measure long
distances using two microwave transmitter/receivers.
• During the late 1950s Geodimeter introduced Electronic Distance
Measurement (EDM) equipment. EDM units use a multi frequency
phase shift of light waves to find a distance. These instruments
saved the need for days or weeks of chain measurement by
measuring between points kilometers apart in one go.
• Advances in electronics allowed miniaturization of EDM. In the 1970s the first instruments
combining angle and distance measurement appeared, becoming known as Total
Stations. Manufacturers added more equipment by degrees, bringing improvements in
accuracy and speed of measurement. Major advances include tilt compensators, data
recorders, and on-board calculation programs.
Modern era 7

8. • The first satellite positioning system was the US Navy TRANSIT system.
• Surveyors found they could use field receivers to determine the location of a point.
• GPS used a larger constellation of satellites and improved signal transmission to
provide more accuracy.
• As in 21st century the theodolite, total station, and RTK GPS survey remain the primary
methods in use.
• Remote sensing and satellite imagery continue to improve and become cheaper,
allowing more commonplace use.
• Prominent new technologies include three-dimensional (3D) scanning and use of lidar
for topographical surveys. UAV technology along with photogrammetric image
processing is also appearing.
Modern Era 8

9. List of Surveying Instruments
• Dumpy level
• Tilting level
• Transit level
• Auto Level
• Digital/Electronic Level
• Tellurometer
• Tachymeter
• Laser Level
• Theodolite
• Total station
• GNSS
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10. Dumpy level
• A level is an optical instrument used to establish or verify points in the same
horizontal plane in a process known as levelling, and is used in conjunction
with a levelling staff to establish the relative heights levels of objects or
marks.
• It is widely used in surveying and construction to measure height differences
and to transfer, measure, and set heights of known objects or marks.
• Dumpy level or the historic "Y" level. It operates on the principle of
establishing a visual level relationship between two or more points, for which
an inbuilt telescope and a highly accurate bubble level are used to achieve
the necessary accuracy.
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11. • The Y level is the oldest and bulkiest of the older style optical instruments. A
low-powered telescope is placed in a pair of clamp mounts.
• The instrument then leveled using a Spirit level, which is mounted parallel to
the main telescope.
• A spirit level, bubble level, or simply a level, is an instrument designed to
indicate whether a surface is horizontal (level) or vertical (plumb).
• A Tilting level is a variant which has a precision vertical adjustment screw
which tilts both the telescope and the high accuracy bubble level attached to
it to make them level.
This reduces the complete reliance on the levelling accuracy of the
instrument's bottom mount, and the "split bubble" display gives additional
assurance that the telescope is level whilst taking the sight.
• A Transit level also has the ability to measure both the altitude and azimuth of
a target object with respect to a reference in the horizontal plane.
The instrument is rotated to sight the target., and the vertical and horizontal
angles are read off calibrated scales.
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12. Auto Level
• An Auto level consists of a precision telescope with crosshairs and Stadia
marks, the cross hairs are used to establish the level point on the target.
• The complete unit is normally mounted on a tripod, and the telescope can
freely rotate 360° in a horizontal plane.
• An automatic level, self-levelling level, or builder's auto level includes an
internal Compensator mechanism (a swinging prism) that, when set close to
level, automatically removes any remaining variation. This reduces the need
to set the instrument base truly level, as with a dumpy level. Self-levelling
instruments are the preferred instrument on building sites, construction, and
during surveying due to ease of use and rapid setup time.
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13. Digital Electronic Level
• A digital electronic level is also set level on a tripod and reads a bar-coded
staff using electronic laser methods.
The height of the staff where the level beam crosses the staff is shown on a
digital display.
• This type of level removes interpolation of graduation by a person, thus
removing a source of error and increasing accuracy. During night time, the
dumpy level is used in conjunction with an auto cross laser for accurate scale
readings.
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14. Laser Level
• In surveying and construction, the laser level is a control tool consisting of a
rotating laser beam projector that can be fixed to a tripod.
• The tool is leveled according to the accuracy of the device and projects a fixed
red or green beam in a plane about the horizontal and/or vertical axis.
• A rotary laser level is a more advanced laser level in that it spins the beam of light
fast enough to give the effect of a complete 360 degree horizontal or vertical
plane, thus illuminating not just a fixed line, but a horizontal plane.
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15. What is leveling?
• The principle of levelling is to obtain horizontal line of
sight with respect to which vertical distances of the points
above or below this line of sight are found.
• Based on the observation points and instrument positions
direct leveling is divided into different types as follows:
• Simple leveling
• Differential leveling
• Fly leveling
• Profile leveling
• Precise leveling
• Reciprocal leveling
Leveling 15

16. Leveling
• How is Levelling done?
• Levelling is the art of determining the relative elevations of different objects
or points on the earth's surface. This is done by taking measurements in
the vertical plane. Hence, this branch of surveying deals with
measurements in vertical planes.
• How do you check Levelling?
• If the levelling starts from a permanent bench mark and ends on a
permanent bench mark the difference between the sums of the back and
fore sights must agree with the difference of levels between the first and
the final bench mark within permissible limits of the closing error.
• What is Rise and Fall method?
• Rise and Fall Method is the method of calculating the difference in
elevation between consecutive points in levelling work. Some of the points
you have to know before starting numerical are: Back sights: The first
reading after seeing the instrument is called back sights.
Leveling 16

17. • What is height of instrument in Levelling?
• In survey leveling, the vertical height of the line of collimation of the instrument over
the station above which it is centered, or above a specified datum level. In spirit
leveling, the vertical distance from datum to line of sight of the instrument.
• 5 Main Sources of Error in Levelling | Surveying
• Imperfect adjustment, This is most common and serious source of error, it can be
eliminated
• Defective level tube
• Shaky tripod
• Incorrect graduations of the staff
• Careless levelling-up of the instrument
• Checking Auto Level Accuracy
• Set up instrument in an area that is as level as possible and which is about 220 feet
long. ...
• Take a reading on each rod with the instrument (or mark each piece of strapping
where the crosshair is sighted).
• Move transit to another spot on the line and take readings and mark both rods
again.
• The difference between the marks on the rod will be the error of the instrument.
Leveling 17

18. Theodolite
• A theodolite is a precision optical instrument for measuring angles between
designated visible points in the horizontal and vertical planes.
• The traditional use has been for land surveying, but they are also used
extensively for building and infrastructure construction, and some specialized
applications such as meteorology and rocket launching.
• It consists of a moveable telescope mounted so it can rotate around
horizontal and vertical axes and provide angular readouts.
• In a theodolite, the telescope is short enough to rotate through the zenith,
otherwise for non-transit instruments vertical (or altitude), rotation is restricted
to a limited arc. The optical level is sometimes mistaken for a theodolite, but it
does not measure vertical angles, and is used only for levelling on a
horizontal plane.
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19. Total station
• A total station (TS) is an electronic/optical instrument used for surveying and
building construction.
• It is an electronic transit theodolite integrated with electronic distance
measurement (EDM) to measure both vertical and horizontal angles and the
slope distance from the instrument to a particular point, and an on-board
computer to collect data and perform triangulation calculations.
• Robotic or motorized total stations allow the operator to
control the instrument from a distance via remote control.
This eliminates the need for an assistant staff member as
the operator holds the retroreflector and controls the total
station from the observed point. These motorized total
stations can also be used in automated setups known as
Automated Motorized Total Station (AMTS).
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20. GNSS
• A satellite navigation is a system that uses satellites to provide autonomous
geo-spatial positioning.
• It allows small electronic receivers to determine their location (longitude,
latitude, and altitude/elevation) to high precision (within a few centimeters to
meters) using time signals transmitted along a line of sight by radio from
satellites.
• The system can be used for providing position, navigation or for tracking the
position of something fitted with a receiver (satellite tracking).
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21. GNSS systems that provide enhanced accuracy and integrity monitoring usable
for civil navigation by their roles in the navigation system, systems can be
classified as:
• Core Satellite navigation systems, currently GPS (United States), GLONASS
(Russian Federation), Beidou (China) and Galileo (European Union).
• Global Satellite Based Augmentation Systems (SBAS) such as Omnistar and
StarFire.
• Regional SBAS including WAAS (US), EGNOS (EU), MSAS (Japan) and
GAGAN (India).
• Regional Satellite Navigation Systems such as India's NAVIC, and Japan's
QZSS.
• Continental scale Ground Based Augmentation Systems (GBAS) for example
the Australian GRAS and the joint US Coast Guard, Canadian Coast Guard,
US Army Corps of Engineers and US Department of Transportation National
Differential GPS (DGPS) service.
• Regional scale GBAS such as CORS networks.
• Local GBAS typified by a single GPS reference station
operating Real Time Kinematic (RTK) corrections.
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22. Why GNSS?
• It offers a higher level of accuracy than conventional surveying methods
• Calculations are made very quickly and with a high degree of accuracy
• GPS technology is not bound by constraints such as visibility between
stations
• Land surveyors can carry GPS components easily for fast, accurate data
collection
• Some GPS systems can communicate wireless for real-time data delivery
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23. Thank You
The end 23