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

4

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

5

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

6

7

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.

8

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.

9

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)

10

I. Electronic Distance Meter

(EDM)

11

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.

12

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.

13

NI 45 Citation EDM

Stand Alone

In Yoke on Theodolite

Standards

In Yoke

on

Tribratch

In Yoke on

Theodolite

Telescope

14

Control Panel of

NI 450 Citation EDM

15

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

16

II. Electronic Digital

Theodolite (EDT)

17

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.

18

Sokkia DT 6 Digital Theodolite

Control

Panel of

Sokkia

DT 6

Illuminated

Display of

Sokkia

DT 6

19

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

20

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

21

EDT: Optional Accessories

1. Diagonal Eyepiece,

2. Zenith Prism,

3. Circular Compass,

4. Solar Prism,

5. Tubular Compass.

1 2 3

4 5

22

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.

23

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.

24

III. Electronic Total Station

25

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

26

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

27

User Friendly Control Panel of

TPS 407 Total Station

Function Keysfor immediate access

Navigation Keyfor fast operation

Fixed Keysfor direct access

ESCmove back

ENTERConfirmation

28

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

29

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

30

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

31

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

32

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

33

IV. Digital Level

34

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.

35

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.

36

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.

37

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.

38

Optical V/s Digital Level For Time

39

Digital Level: Front View

40

Digital Level: Rear View

41

Digital Levels: Data and/or

S/W Up/Down Load Through PC Card

V. Laser Beam

Instruments

42

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.

45

Alignment Laser

46

Grade Laser

47

Laser Plummet

48

Levelling Laser or Laser Level & Laser

Detector

49

Laser Level for Levelling at the Floor

50

Laser Level to Make Reference Marks on

a Wall

51

Laser Level in Setting Grade for Pipe Bed

52

Laser Level in Fixing of False Ceiling

53

Laser Control System for Construction

Equipments

54

Laser Control System for Construction

Equipments

55

Laser Control System for Construction

Equipments

56

3D Laser Scanner

57

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.

58

LIDAR Scanner Used in Land Survey

59LIDAR means Light Interference & Ranging

VI. Space Based

Positioning Systems

(SBPS)

60

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.

61

62

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.

63

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.

64

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

65

66

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)’.

67

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.

68

Segments of SBPS

69

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.

70

SBPS Receivers II

Typical

Handheld

Navigational

Receiver

71

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

72

SBPS Receivers IV

Typical Geodetic Receiver & Antenna

73

SBPS Receivers V

Typical Mapping Type Antenna & Receiver

74

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)

75

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

76

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

77

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

78

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.

79

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.

80

Principal Features of ETS

4 (a) Effective control on work through Lumi

Guide

81

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.

82

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.

83

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

84

Principal Features of ETSRobotic Operation

(Wireless Remote Controlled Operation)

Note that

instrument is

getting operated

itself.

Nobody is

operating it

85

Principal Features of

ETS12. Friction Lock & Endless Drives

86

Principal Features of ETS13. Direct Reading

87

Principal

Features of ETS14. Automatic

Detection of True

North Through Gyro

Attachment

88

Principal Features of ETS15. Card Drive

89

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

90

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