MODERN SURVEYING TECHNIQUES

MODERN SURVEYING

TECHNIQUESCONTEMPRORY TECHNOLOGIES

PRESENTED BY:

JYOTI ARORA

MEGHA SHARMA

WHAT IS SURVEYING?

• Surveying is defined as the science ofmaking measurements especially ofthe earth surface. This is being doneby finding out the spatiallocation(relative/absolute) of pointson or near the earth surface.

• Different method and instrument arebeing used to facilitate the work ofsurveying.

OBJECTIVE OF SURVEYING

1. To collect field data.

2. To prepare plan or map of the area surveyed.

3. To analyze and calculate the field parameters

for setting out operation of actual engineering work .

Surveyors work with elements of geometry, trigonometry, physics, engineering, metrology, programming languages and regression analysis.

MODERN SURVEYING EQUIPMENT

• DIGITAL LEVEL

• EDMI – ELECTRO MAGNETIC

• TOTAL STATION

• REMOTE SENSING

DIGITAL LEVELDigital levels use electronic image

processing to evaluate the special bar-coded staff reading.

• This bar-coded pattern is converted into elevation and distance values using a digital image matching procedure within the instrument.

USES: For measuring elevations, height difference, levelling of ceiling.

SALIENT FEATURES OF DIGITAL LEVEL

• Fatigue-free observation as visual staff reading by theobserver is not required.

• User friendly menus with easy to read, digital displayof results.

• Measurement of consistent precision and reliabilitydue to automation.

• Automatic data storage eliminates booking and itsassociated errors.

WORKABILITY:

• The purpose of electronic staff reading, a beam splitter is incorporated which transfers the bar code image to a detector diode array.

• The light, reflected from the white elements only of the bar code, is divided into infrared and visible light components by the beam splitter.

• The visible light passes on to the observer.

• The acquired bar code image is converted into an analogous video signal, which is then compared with a stored reference codes.

EDMI: ELECTRO MAGNETIC

EDMI measures slope distance between transmitter and receiver by modulating the continuous carrier wave at different frequencies, and then measuring the phase difference at the master station between the outgoing and the incoming signals.

OPERATION WITH EDMI

It involves four basic steps:(a) Set up(b) Aim(c) Measure(d) Record

Setting up: The instrument is centered over a station by means of tribrach. Reflector prisms are set over the remote station on tribrach.

Aiming: The instrument is aimed at prisms by using sighting devices or theodolite telescope. Slow motion screws are used to intersect the prism centre. Some kind of electronic sound or beeping signal helps the user to indicate the status of centering.

Measurement: The operator presses the measure button to record the slope distance which is displayed on LCD panel.

Recording: The information on LCD panel can be recorded manually or automatically.

ERROR IN MEASUREMENT WITH EDMI

1. Instrument error

2. Atmospheric errors

3. Instrumental error

TOTAL STATION

This instruments can record horizontal and vertical angles together with slope distance and can be considered as combined EDM plus electronic theodolite.

SALIENT FEATURES OF TS

• TS captures the spatial data for a three-dimensional position fix.

• The angles and distances are displayed on a digital readout and can be recorded.

Various components of a typical TS are shown in Figure:

FIELD OPERATION WITH TS

The programs need at least one identified reference station so that all subsequent stations can be identified in terms of (X, Y, Z).

It include the following functions

• Point location

• Missing line measurement (MLM)

• Resection

• Remote distance and elevation measurement

• Offset measurements

• Layout or setting out operation

• Area computation

Different Types of TS and accessories

• Trimble(5600IR)

REMOTE SENSING

• Science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation

Remote sensing system consists of the following sub-systems:(a) scene

(b) sensor

(c) processing (ground) segment

How remotely sensed data gets converted into useful information:

1. Source of EM energy (sun/self emission: transmitter onboard sensor).

2. Transmission of energy from the source to the surface of the earth and its interaction with the atmosphere (absorption/scattering).

3. Interaction of EMR with the earth surface (reflection, absorption, transmission) or re-emission/self emission.

4. Transmission of reflected/emitted energy from the surface to the remote sensor through the intervening atmosphere.

5. Recording of EMR at the sensor and transmission of the recorded information (sensor data output) to the ground.

6. Preprocessing, processing, analysis and interpretation of sensor data.

7. Integration of interpreted data with other data sources for deriving management alternatives and applications.

APPLICATION OF REMOTE SENSING

Agriculture:-

• Crop condition assessment.

• Crop yield estimation

Urban Planning:-

• Infrastructure mapping.

• Land use change detection.

• Future urban expansion planning

• Hydrology

• Forestry And Ecosystem

• Ocean applications

• Disaster management

IN CYCLONE:MITIGATION PREPAREDNESS RESCUE RECOVERY SATELLITES USED:

Risk modelling;vulnerability analysis.

Early warning;long-range climate modelling

Identifying escape routes;crisis mapping;impact assessment;cyclone monitoring;storm surge predictions.

Damage assessment;spatial planning.

KALPANA-1; INSAT-3A; QuikScatradar; Meteosat

Cyclone Lehar by KALPANA 1 Cyclone Helen by Mangalayan

Example:

IN EARTHQUAKES:MITIGATION PREPAREDNESS RESCUE RECOVERY SATELLITES USED

Building stock assessment;hazard mapping.

Measuring strain accumulation.

Planning routes for search and rescue;damage assessment;evacuation planning;deformation mapping.

Damage assessment;identifying sites for rehabilitation.

PALSAR;IKONOS 2;InSAR; SPOT; IRS

The World Agency of Planetary Monitoring and Earthquake Risk Reduction (WAPMERR) uses remote sensing to improve knowledge of building stocks — for example the number and height of buildings. High resolution imagery can also help hazard mapping to guide building codes and disaster preparedness strategies.

IN FLOODS:MITIGATION PREPAREDNESS RESCUE RECOVERY SATELLITES USED

Mapping flood-prone areas;delineating flood-plains;land-use mapping.

Flood detection;early warning;rainfall mapping.

Flood mapping;evacuation planning;damage assessment.

Damage assessment;spatial planning.

Tropical Rainfall Monitoring Mission;AMSR-E; KALPANA I;

Sentinel Asia — a team of 51 organisations from 18 countries — delivers remote sensing data via the Internet as

easy-to-interpret information for both early warning and flood damage assessment across Asia.It uses the Dartmouth Flood Observatory's (DFO's) River Watch flood detection and measurement system, based on AMSR-E data, to map flood hazards and warn disaster managers and residents in flood-prone areas when rivers are likely to burst their banks.

Flood In Uttarakhand Flood In Assam

IN OTHER DISASTERS:

DISASTER MITIGATION PREPAREDNESS RECOVERY RESCUE SATELLITES USED

DROUGHT Risk modelling;vulnerability analysis;land and water management planning.

Weather forecasting;vegetation monitoring;crop water requirement mapping;early warning.

Monitoring vegetation;damage assessment.

Informing drought mitigation.

FEWS NET; AVHRR; MODIS; SPOT

VOLCANO Risk modelling;hazard mapping;digital elevation models.

Emissions monitoring;thermal alerts.

Mapping lava flows;evacuation planning.

Damage assessment;spatial planning.

MODIS and AVHRR; Hyperion

FIRE Mapping fire-prone areas;monitoring fuel load;risk modelling.

Fire detection;predicting spread/direction of fire;early warning.

Coordinating fire fighting efforts.

Damage assessment.

MODIS; SERVIR; Sentinel Asia; AFIS

LANDSLIDE Risk modelling;hazard mapping;digital elevation models.

Monitoring rainfall and slope stability.

Mapping affected areas;

Damage assessment;spatial planning;suggesting management practices.

PALSAR;IKONOS 2;InSAR; SPOT; IRS