(FAMILARISATION WITH(FAMILARISATION WITH
Modern equipmentsModern equipments
EDM – Electronic distance measurement eqp.EDM – Electronic distance measurement eqp.
Auto level.Auto level.
Digital level.Digital level.
Total station.Total station.
GPS – global positioning system.GPS – global positioning system.
Now separate EDM are not very popular , insteadNow separate EDM are not very popular , instead
Total Station which have in built EDM is beingTotal Station which have in built EDM is being
used .used .
Measurement of distance is accomplished with aMeasurement of distance is accomplished with a
modulatedmodulated microwavemicrowave oror infraredinfrared carrier signal,carrier signal,
generated by a small solid-state emitter within thegenerated by a small solid-state emitter within the
instrument's optical path, and bounced off of theinstrument's optical path, and bounced off of the
object to be measured. The modulation pattern inobject to be measured. The modulation pattern in
the returning signal is read and interpreted by thethe returning signal is read and interpreted by the
onboard computer in the EDM. The distance isonboard computer in the EDM. The distance is
determined by emitting and receiving multipledetermined by emitting and receiving multiple
frequencies, and determining the integer numberfrequencies, and determining the integer number
ofof wavelengthswavelengths to the target for eachto the target for each frequencyfrequency..
Most total stations use a purpose-built glassMost total stations use a purpose-built glass
PorroPorro prismprism as the reflector for the EDMas the reflector for the EDM
signal, and can measure distances out to a fewsignal, and can measure distances out to a few
kilometers, but some instruments arekilometers, but some instruments are
"reflectorless", and can measure distances to"reflectorless", and can measure distances to
any object that is reasonably light in color, outany object that is reasonably light in color, out
to a few hundred meters. The typical Totalto a few hundred meters. The typical Total
Station EDM can measure distances accurateStation EDM can measure distances accurate
to about 3 millimeters or 1/100th of a foot.to about 3 millimeters or 1/100th of a foot.
Hand held EDMHand held EDM
Very handy,Very handy,
Can be used withCan be used with
accuracy of 10mm oraccuracy of 10mm or
Useful for remoteUseful for remote
measurements likemeasurements like
contact wire etc.,contact wire etc.,
Early age levelsEarly age levels
Early age levels areEarly age levels are
Dumpy levels.Dumpy levels.
Tilting levels.Tilting levels.
AUTO LEVELAUTO LEVEL
Now most commonlyNow most commonly
used levellingused levelling
instruments are - Autoinstruments are - Auto
Auto level, as nameAuto level, as name
sounds it has a autosounds it has a auto
level compensator andlevel compensator and
corrects automaticallycorrects automatically
if instrument goes outif instrument goes out
of level within it’sof level within it’s
With auto level:-With auto level:-
Survey work can be done fast,Survey work can be done fast,
Less chances of error,Less chances of error,
Magnification available is more,Magnification available is more,
Range is more,Range is more,
Image is erect so less chances ofImage is erect so less chances of
Digital levelDigital level
They are not popular instead autoThey are not popular instead auto
levels are more extensively used.levels are more extensively used.
The Trimble DiNi Digital Level :The Trimble DiNi Digital Level :
Determine accurate heightDetermine accurate height
information 60% faster than withinformation 60% faster than with
automatic levelingautomatic leveling
Eliminate errors and reduceEliminate errors and reduce
rework with digital readingsrework with digital readings
Transfer data to the office easilyTransfer data to the office easily
Measure to a field of just 30 cmMeasure to a field of just 30 cm
TOTAL STATIONTOTAL STATION
A total station integrates the functions of a theodolite
for measuring angles, an EDM for measuring
distances, digital data and a data recorder. Examples
of total stations are the Sokkia Set4C and the
Geodimeter 400 series. All total stations have similar
constructional features regardless of their age or level
of technology, and all perform basically the same
Total solution for surveyingTotal solution for surveying
Most accurate and userMost accurate and user
Gives position of a point (x, yGives position of a point (x, y
and z) w. r. t. known pointand z) w. r. t. known point
(base point),(base point),
EDM is fitted inside theEDM is fitted inside the
Digital display,Digital display,
On board memory to store data,On board memory to store data,
Compatibility with computers,Compatibility with computers,
Measures distance and angles and displaysMeasures distance and angles and displays
Auto level compensator is available,Auto level compensator is available,
Can work in lesser visibility also,Can work in lesser visibility also,
Can measure distances even without prismaticCan measure distances even without prismatic
target for lesser distances,target for lesser distances,
Is water proof,Is water proof,
On board software are available,On board software are available,
Can be used for curve layout after feeding data.Can be used for curve layout after feeding data.
New tNew total stationsotal stations have atmospherichave atmospheric
correction, and auto-focus. In addition, thesecorrection, and auto-focus. In addition, these
series incorporates a quick distance measuringseries incorporates a quick distance measuring
mode and a high data storage capacity formode and a high data storage capacity for
increased productivity.increased productivity.
The newThe new Total stationTotal station gives the uniquegives the unique
opportunity for long range distance monitoringopportunity for long range distance monitoring
of up to 9000m to a single prism. Using theof up to 9000m to a single prism. Using the
scan functionality of software allows fullyscan functionality of software allows fully
automated monitoring of the prism in directionautomated monitoring of the prism in direction
of the line of sight.of the line of sight.
Total Stations can be used for:
General purpose angle measurement
• General purpose distance measurement
• Provision of control surveys
• Contour and detail mapping
• Setting out and construction work
Factors influencing the use of Total Stations:
• A clear line of sight between the instrument
and the measured points is essential.
• The precision of the instrument is dependent on
the raw repeatabilities of the direction and
• A well defined measurement point or
target/prism is required to obtain optimal
precision and accuracy.
• The accuracy of direction and distance
measurement is subject to a number of
instrumental errors and the correct field
Auxiliary Equipment Required
• Targets or Prisms to accurately define the
target point of a direction measurement.
• A data recorder if one is not integrated into the
• A download cable and software on a PC to
capture and process the captured digital data to
produce contour and detail maps.
Display at target also,Display at target also,
No need of operator onNo need of operator on
Moves automatically toMoves automatically to
predetermined directionpredetermined direction
and focuses automaticallyand focuses automatically
at target at specifiedat target at specified
Can be integrated withCan be integrated with
GPS also.GPS also.