Why Advanced Equipments?mitpolytechnic.ac.in/downlaods/09_knowledge-bank/...Few Requirements of...
Transcript of Why Advanced Equipments?mitpolytechnic.ac.in/downlaods/09_knowledge-bank/...Few Requirements of...
Why Advanced Equipments?
• Ever increasing need of Housing &
Infrastructural development on account of
Growing Population & Rapid Urbanization.
• Restricted Outlay
• Inflation
• Policy Benefits/Incentives
• Human Limitations/Labour Problems
• Higher Precision/Accuracy
• High Turnover 1
Few Requirements of
Advanced Equipments• Single unit shall handle large quantum of Work.
• Rapid Speed of Work.
• Easy Updating to suit changed work conditions.
• Precise/Accurate Work Output
• Least Human Interference.
• Ease of Operation & Maintenance
• Digital Control/Output.
• Computer Compatibility 2
SURVEYING• Flawless decisions about project plans, designs &
execution needs lot of information in terms of
plannimetric dimensions, undulations & relative
positions of various things at the proposed site.
• To generate such an information lot of data needs to be
collected at project site by the way of surveying.
• Surveying is an art of making measurements on the
surface of earth to define relative positions of the points,
places, objects etc. in horizontal and vertical plane, with
the help of which one may prepare plans, maps and
sections.3
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Basic Operations in All Classes
Surveying
1. To establish the controls stations
2. To locate the details
A
B
C
D
E
ABCDEA is the area to be surveyed
A,B,C,D & E are the control stations
- Details to be located
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Basic Operations in Establishment of
Control or in Locating the Details
1. To measure directions,
2. To measure distances in H & V planes,
The planimetric Position of C can be defined by any one of the following way
1. Measuring direction angles CAB & CBA or
2. Measuring distances CA & CB or
3. Measuring direction angle CAB & distance CA or
4. Measuring direction angle CBA & distance CB or
5. Measuring Perpendicular distance CD & distacne AD or BD
A
C
B
D
Instruments For Surveying
• Distance Measuring Instruments
• To measure distances in horizontal Plane
• To Measure Distance in Vertical Plane
• Direction Measuring Instruments
• Absolute Direction
• Relative Direction
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Merits of Conventional Surveying
Instruments/Methods
• Simple in construction,
• Low capital cost,
• Almost no operating cost,
• On field repair/adjustment is possible,
• Local Manufacture & Service,
• Almost no compute awareness essential.
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Demerits of Conventional Surveying
Instruments/Methods
• Laborious & Fatiguing,
• Low & Constant/invariable precision,
• Measurement, especially angular, needs to be done in parts,
• Different instrument for different process of measurement,
• Number of instruments for same process of measurement,
• Manual Reading, Recording, Corrections & Reductions, No
computer compatibility,
• Achieving higher accuracies is relatively difficult & costly,
• Time Consuming.
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Advanced Instruments In Surveying
• The Electronic Distance Meters (EDM)
• The Electronic Digital Theodolites (EDT)
• The Electronic Digital Levels (EDL)
• The Electronic Total Stations (ETS)
• Laser Beam Instruments
• Space Based Positioning Systems (SBPS)
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I. Electronic Distance Meter
(EDM)
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EDM: Introduction
• The range varies from 0.5 km to 100 km or even more.
• Accuracy offered varies from 1:10000 to 1: 100000 & even
more.
• Makes use of Electro Magnetic waves (Micro & Optical).
• Works on the principle of Phase Comparison.
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EDM: Types
I. As per type of Electro-magnetic waves used
1. Electro Optical Distance Meter (EODM)
2. Microwave Distance Meter (MDM)
II. As per measuring range
1. Short range (D ≤ 5 km) …usually EODM
2. Medium Range (5km ‹ D ‹ 100 km) … May be EODM/MDM
3. Long Range (D › 100 km) … usually MDM
III. As per way of operation
1. Transmitting Type - MDM
2. Reflecting Type – IR EODM
3. Direct Reading – Laser EODM
The accuracy of the measurement varies from type to type but is usually in
the order of +0.005m + 1:10,000 x distance.
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NI 45 Citation EDM
Stand Alone
In Yoke on Theodolite
Standards
In Yoke
on
Tribratch
In Yoke on
Theodolite
Telescope
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Control Panel of
NI 450 Citation EDM
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EDM: Advantages & Disadvantages
Advantages
• Can measure distance even in multiples of km at a stretch
• Can measure such a long distance in just few seconds
• Can measure distance even to a mm accuracy with very high precision.
Disadvantages
• Problem of misalignment when mounted on theodolite
• Measures distance along the line of sight
• Distance needs to be corrected for eccentricity of EDM axis & theodolite axis
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II. Electronic Digital
Theodolite (EDT)
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EDT: Reading Systems
• Absolute encoders gives output on the basis of unique
digital response for each individual increment of
displacement. Detection of 0° position is no longer needed.
Stable, high-accuracy measurement.
• Incremental encoders give rise to an output based on he
numbers periods or counts between start & finish of the
whole displacement. Thus start position has to be known for
the determination of the measurement.
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Sokkia DT 6 Digital Theodolite
Control
Panel of
Sokkia
DT 6
Illuminated
Display of
Sokkia
DT 6
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EDT: Features
1. Optical / Laser plummet on tribratch / alidade.
2. Laser pointer.
3. Clockwise or anti clockwise horizontal anglemeasurement.
4. Vertical angle measurement in different modes.
5. Quick zero setting of the horizontal circle
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EDT: Features (Contd….)
• Horizontal Angle hold facility
• Illuminated display & diaphragm
• Built in vertical axis compensator
• Coaxial tangent & clamp or friction clamp with limitless tangent screw
• Variable least count
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EDT: Optional Accessories
1. Diagonal Eyepiece,
2. Zenith Prism,
3. Circular Compass,
4. Solar Prism,
5. Tubular Compass.
1 2 3
4 5
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EDT: Typical Display
1 2 3 4 5
1. Illumination Key: Switch on/off background LEDs,
2. % / VA KEY: Changes the measuring mode of vertical Angle,
3. R/L Key: Changes measuring direction of H angles from
clockwise to anticlockwise & vice a versa.
4. Hold Key: Holds & keeps unchanged the value of H angle,
5. Reset Key: Sets horizontal angle value to zero.
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EDT: Water Tightness
• The EDTs are considerably watertight
• Water tightness is expressed as IP 54, IP 64 (International System)
• EDTs Confirming to IP 64 are more water tight than IP 54
• Screws of more water tight instrument are more tightly operating.
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III. Electronic Total Station
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Total Station is modern electronic digital
surveying instrument having facility of measuring
distances & directions simultaneously.
It is basically an electronic digital theodolite,
provided with an EDM in it’s telescope.
A processor with sufficient non volatile memory
is also provided to store & process up to certain
extent, on board/at site itself, the data
systematically.
A total station can establish interface with
outboard computer like desktop/laptop etc. for
exchange of the data & programmes.
What is a Total Station ?
An Electronic
Total Station
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Components of TPS 407 Total Station
Removable handle
Endless drives
Measure key
EDM Infrared (IR) and
reflectorless (RL)
Camcorder battery
Extra-Large,
high resolution
display
Navigation key
Softkeys
Internal memory:
10.000 data blocks
Dual-axis
Compensator
Serial Interface
ON/OFF key
Leica precision optics
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User Friendly Control Panel of
TPS 407 Total Station
Function Keysfor immediate access
Navigation Keyfor fast operation
Fixed Keysfor direct access
ESCmove back
ENTERConfirmation
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1. Measures direction & distance simultaneously
2. Effortless levelling through electronic digital bubble
3. Effortless centering through laser plummet
4. Effective control on work through:
a) Track light or Lumi guide,
b) Voice communication.
Principal Features of ETS I
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5. Automatic Correction For
i) Temperature & Pressure
ii) Curvature
iii) Refraction
iv) Closing Error
6. Multi Axis Compensator
Single, double or triple.
7. Data Storage Facility
i) On board
ii) Built in extra or external drive
8. Data Downloading and Uploading Facility
Principal Features of ETS II
A Single Prism Reflector
with target Plate
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Principal Features of ETS III9. On board Computer
10.Variable Accuracy
11.Robotic operation
12.Friction lock & Endless
Drives
13.Direct Reading
14.Automatic detection of true
north
15.Card Drive
16.Graphic Display with
functions like pan, zoom etc.
17.Automatic target recognition
18.File Management.
ATrimble
Robotic Total Station
360° Power (Active)
Reflector For Robotic
Total Station
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Basic Common Inbuilt Programmes
1. Reduction of co-ordinates
2. Area & Perimeter Calculation
3. Remote Elevation Measurement
4. Missing Line Measurements
5. Offset Measurements
6. Resection or free stationing
7. COGO (Co-ordinate Geometry)
8. Tracking & Setting Out
9. TraversingA Geodimeter
ETS
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More accurate distance and angle measurements.
Elimination of manual errors.
Elimination of mathematical reductions.
Generation of data in digital format.
Zero plottable error.
Reduction of labour, time and cost.
Professional output and quality product.
Advantages of Total Station
A Triple
Prism
Reflector
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IV. Digital Level
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Digital Levels
The Digital Levels uses technique of digital image processing for determining heights & distances.
Features of Digital Levels
• Measuring Range: Up to 100m.
• Measuring Accuracies: 1. Staff reading: 1.2 to 4mm.
2. Distances 1 to 5cm (Tape accuracy).
• Precision: 1.5 to 4mm per km of double run levelling.
• Fully automatic error free measurements with high precision Digital Display.
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Digital Levels
Features of Digital Levels (Contd…)
• Built in or Plug in type data storage/recording module.
• Increased Work productivity up to 50%
• The alphanumeric keyboard
• Data up/down loading
• post processing without errors with help of softwares like Delta or Levnet.
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Digital LevelsFeatures of Digital Levels (Contd…)
• Special multiple measurement techniques: You can calculate
the mean or median The required standard deviation for the
mean can be entered in advance. The instrument measures until
this value is reached & then stops automatically.
• Automatic numbering of staff stations for the purpose of
recording.
• Option of extended/enhanced system accuracy for highest
precision.
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Digital Levels
Programmes Usually Available on Board
• Reduction of Elevations in profile levelling, cross
sectioning & contour surveying.
• To Set Out A Point At Required Elevation, required in
case of tracing grade contour, direct contouring, lining out
etc.
• Correction For Temperature Changes.
• MKS to FPS conversions.
• Accommodation of Earths Curvature.
• Adjusting for Collimation Error.
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Optical V/s Digital Level For Time
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Digital Level: Front View
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Digital Level: Rear View
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Digital Levels: Data and/or
S/W Up/Down Load Through PC Card
V. Laser Beam
Instruments
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Introduction
• Principal Features of Laser Light
1. It is monochromatic (of one colour),
2. It is coherent,
3. It has very low divergence.
4. Provides visible reference line/plane with respect to set
outline, level & grade.
• Principal Applications of Laser Instruments
1. As an aligner to set/mark the alignment of a structure,
2. To set gradient for a structure,
3. As a plumb to attain centering of the instruments,
4. As a level to provide visible line/plane of collimation,
5. To check verticality of structure/structural member.43
Distinguishing Features of Laser From
Surveying/Construction Point of View
1. Travels in a straight line & does not sag.
2. Sets up to a true reference line that project a well
defined bright spot or point exactly at the point of work.
3. The range of (Survey) laser in broad day light is about
250m, before sunrise & after sunset it’s range is about
400m, where as under darkness it may be up to 2 km.
4. The problem of invisibility to human eye in bright
sunlight. can be solved by using special detector.
5. Permits free movement of men & material around it, as
only Class I or Class II lasers are used on such
instruments. 44
Types of Lasers
Following are main two types of lasers
1. Single Beam Lasers &
2. Rotating Beam Lasers.
1. Single Beam Laser
These laser projects visible string line or plumb line utilised
in linear or vertical alignment applications such as
tunnelling, sewer pipe placement and building
construction.
e.g. Alignment Laser, Grade Laser, Laser Plummet.
2. Rotating Beam Lasers
These are merely single beam lasers with spinning optics
that rotates the beam in horizontal or vertical plane,
thereby creating necessary plane of reference.
e.g. Levelling Lasers or Laser Levels.
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Alignment Laser
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Grade Laser
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Laser Plummet
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Levelling Laser or Laser Level & Laser
Detector
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Laser Level for Levelling at the Floor
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Laser Level to Make Reference Marks on
a Wall
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Laser Level in Setting Grade for Pipe Bed
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Laser Level in Fixing of False Ceiling
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Laser Control System for Construction
Equipments
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Laser Control System for Construction
Equipments
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Laser Control System for Construction
Equipments
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3D Laser Scanner
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Introduction
• 3D laser scanning is a non-intrusive means of rapidlycollecting detailed and accurate raw or as built terraindata.
• This high-definition technology of survey uses a narrowlaser beam to “sweep across” a target terrain, so thathundreds of thousands of closely spacedmeasurements can be taken in a matter of minutes.
• When these scanned measurements are displayed ona computer, a dense representation of the targetterrain results which can be viewed and navigatedmuch like a 3D model.
• In minutes, complete surface geometry is safely andaccurately captured.
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LIDAR Scanner Used in Land Survey
59LIDAR means Light Interference & Ranging
VI. Space Based
Positioning Systems
(SBPS)
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What is SBPS ? - I
• SBPS are the positioning, navigation & timingsystem developed initially by US ‘Department ofDefense (DoD)’ emerged in late 60’s.
• It is the technique of determining the exact positionof any point on land, sea & air around the earth, withhelp of the satellites.
• It is kind of a modern programme allowing new typeof survey, independent of plumb line, a basicreference line in all earlier survey systems.
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What is SBPS ? - II
• It yields positional accuracies even in the
order of sub centimeter.
• With help of SBPS relative position of a station
may be collected in any weather even during
night hours without making any measurement
on the earth’s surface.
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Principle of Positioning With SBPS - I
• In this technique very high precision time signals from atomic(Rubidium-Cesium) clocks on satellites are transmitted.
• The stability of such clock is in the order of 10 -14.
• The receiver on earth can determine its position after processingthe time signals received from such three or more GNSS (GlobalNavigational Satellite System) satellites.
• Such receiver provides position in terms of latitude, longitude &altitude.
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Principle of Positioning With SBPS - II
Different SBPS
• GPS (USA)
NNSS – Transit – Doppler Technique – 1958
NAVSTAR – GPS – Code Technique – 1977
• GLONASS (Russia)
• GALILEO (Europeon Communities) – 2008
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SBPS Coordinates & WGS 84
• SBPS coordinates are not coordinates with reference to meansea surface (i.e. Geoid) but are with respect to the imaginarymathematical ellipsoid such as ‘World Geodetic System of1984 (WGS 84)’.
• The WGS 84 is a 3D, earth centered official reference systemfor GPS developed by ‘National Imagery & Mapping Agency(NIMA)’ of US.
• The WGS 84 is nearly coincident with the ‘InternationalTerrestrial Reference Frame (ITRF)’.
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Segments of SBPS
• The SBPS can be divided in to three segments: the spacesegment, the user segment, and the control segment.
• The space segment consists of the constellation of the GNSSsatellites.
• The user segment consists of various kinds of the users alongwith various types of SBPS receivers.
• The control segment has the task to do monitoring, thecomputations, the data transmission and the supervisionnecessary for the daily control of all the satellites in theconstellation.
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Segments of SBPS
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SBPS Receivers IThe receivers are generally classified as ‘Navigational Receivers’ & ‘Surveying Receivers’.
• Navigational Receivers:
With this type receiver only code pseudo ranges using C/Acode (available only on L1 frequency) are measured.
It is usually a compact hand held device fitted with quartz clock& works on 12V flash batteries.
It gives output in a 3D positioning system like WGS 84 or insome map projection system like ‘Universal TransverseMercator (UTM)’.
Positional accuracies with navigational receivers is in the orderof 5 to 10m in absolute positioning, in the absence SA and fewtens of cm in relative positioning over short base line of fewkms.
They are preferred for determining the absolute coordinate ofthe points.
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SBPS Receivers II
Typical
Handheld
Navigational
Receiver
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SBPS Receivers III
• Survying Receivers:
The surveying receivers are single or dual frequency receiverseither with or without the capacity of receiving P code.
They are little bulky & more expensive than the navigationalreceivers.
They are capable of giving accuracies in the order of few cms inabsolute positioning with precise post processed satellite orbitinformation & of few mm level in relative (Differential/Kinematic)positioning.
They are further divided as Geodetic Receivers & MappingReceives
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SBPS Receivers IV
Typical Geodetic Receiver & Antenna
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SBPS Receivers V
Typical Mapping Type Antenna & Receiver
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SBPS: Positioning Methods I
It involves only one SBPS
receiver that
simultaneously receives
signals from at least four
satellites to determine its
own co-ordinates with
respect to the center of
the earth.
1.Point or Absolute Positioning
(Either SPS or PPS)
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SBPS: Positioning Methods II
Relative positioning
involves two receivers,
one called as a base and
the other called as a
rover, simultaneously
tracking the same
satellites to determine
their relative co-ordinates.
The base whose co-ordinates are known precisely remains
stationary at a site and the rover may or may not be stationary
2. Relative Positioning System
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SBPS Accuracy
• SPS - Standard Positioning Service (CA Code): ≤ 50 m
• PPS - Precise Positioning Service (P Code): ≤ 12 m
• DGPS with SPS Mapping Grade Receiver: ≤ 2 m
• DGPS with PPS Mapping Grade Receiver: ≤ 1m
• RTK - Real Time Kinematic Surveying: ≤ 1cm
• Survey Grade GPS: ≤ ½ cm
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SBPS: Advantages
• Labour Saving.
• Time Saving / fast.
• Signals are available free of cost.
• Accuracy.
• No reference line required.
• Weather independent.
• Free of intervisibility requirements.
• Round the clock availability
• Data in digital format.
• Unlimited uses
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Principal Features of ETS2. Effortless levelling through electronic digital
bubble• In addition to the usual round
&/or elongated bubble/s many
ETS are furnished with electronic
bubbles.
• Sensitivity of such bubbles can
also be changed depending up on
the precision expected.
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Principal Features of ETS
3. Effortless centering through laser plummet
• It’s faster to set up the
instrument with a laser
plummet even in high winds
especially in open areas or at
higher elevations.
• The intensity of laser spot
may be adjusted to the best
view, in the prevailing light
conditions.
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Principal Features of ETS
4 (a) Effective control on work through Lumi
Guide
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Principal Features of ETS5 (i) Automatic Correction For Temp & Pressure
• The built-in automatic
atmospheric sensors
measures temperature &
pressure in real time, &
initiates ppm correction.
• Thus the user no longer
needs to bother with
inputting these data, saving
both time & trouble.
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Principal Features of ETS6. Multi Axis Compensator
With tri-axis correction, in
addition to dual-axis
correction, error which
occurs where the vertical &
horizontal axis intersects is
corrected, as well as error
occurring where horizontal
axis & sight axis intersect.
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Principal Features of ETS8. Data Downloading & Uploading Facility
•Data stored on ETS can be
exchanged between the
instrument and a computer in
desired format (Such as DXF
or so) with RS 232 serial
interface & a data down
loading software such as
Transit or so.
• Individually configurable
data filters permit data output
to be set to your personel
preferences
RS
232
Port
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Principal Features of ETSRobotic Operation
(Wireless Remote Controlled Operation)
Note that
instrument is
getting operated
itself.
Nobody is
operating it
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Principal Features of
ETS12. Friction Lock & Endless Drives
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Principal Features of ETS13. Direct Reading
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Principal
Features of ETS14. Automatic
Detection of True
North Through Gyro
Attachment
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Principal Features of ETS15. Card Drive
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Principal Features of ETS15. Auto Target Recognition
If we want to pin point the
fixed targets then just point
in the general direction of
the target and then
machine it self completes
the fine targeting in a
moment and without
further user input
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