2. WHAT IS SURVEYING?
• Surveying is defined as the science of
making measurements especially of
the earth surface. This is being done
by finding out the spatial
location(relative/absolute) of points
on or near the earth surface.
• Different method and instrument are
being used to facilitate the work of
surveying.
3. 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.
5. DIGITAL LEVEL
Digital 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.
6. SALIENT FEATURES OF DIGITAL LEVEL
• Fatigue-free observation as visual staff reading by the
observer is not required.
• User friendly menus with easy to read, digital display
of results.
• Measurement of consistent precision and reliability
due to automation.
• Automatic data storage eliminates booking and its
associated errors.
7. 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.
8.
9. 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.
10.
11. 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.
12. 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
13. 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 OFTS
• 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:
14. 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
16. 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
17. Remote sensing system consists of the following sub-systems:
(a) scene
(b) sensor
(c) processing (ground) segment
18. 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.
19. 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.
21. IN CYCLONE:
MITIGATION PREPAREDNESS RESCUE RECOVERY SATELLITES USED:
Risk modelling;
vulnerability analysis.
Early warning;
long-range climate
modelling
Identifyingescape routes;
crisis mapping;
impact assessment;
cyclone monitoring;
storm surge predictions.
Damage assessment;
spatial planning.
KALPANA-1;
INSAT-3A;QuikScat
radar; Meteosat
Cyclone Lehar by KALPANA 1 Cyclone Helen by Mangalayan
Example:
22. IN EARTHQUAKES:
MITIGATION PREPAREDNESS RESCUE RECOVERY SATELLITES USED
Building stockassessment;
hazard mapping.
Measuring strain
accumulation.
Planningroutes for search
and rescue;
damage assessment;
evacuation planning;
deformationmapping.
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.
23. 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
24. IN OTHER
DISASTERS:
DISASTER MITIGATION PREPAREDNESS RECOVERY RESCUE SATELLITES USED
DROUGHT Risk modelling;
vulnerability analysis;
land and water
managementplanning.
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;
hazardmapping;
digital elevation models.
Emissionsmonitoring;
thermalalerts.
Mapping lava flows;
evacuation planning.
Damage
assessment;
spatial planning.
MODIS and AVHRR;
Hyperion
FIRE Mappingfire-prone
areas;
monitoringfuel load;
risk modelling.
Fire detection;
predicting spread/direction of
fire;
early warning.
Coordinatingfire
fightingefforts.
Damage
assessment.
MODIS; SERVIR;
Sentinel Asia; AFIS
LANDSLIDE Risk modelling;
hazard mapping;
digital elevation
models.
Monitoringrainfall and slope
stability.
Mapping affected
areas;
Damage
assessment;
spatial planning;
suggesting
management
practices.
PALSAR;
IKONOS 2;
InSAR; SPOT; IRS
