Advanced Surveying,MSBTE,I scheme course content by Mr.Naufil Sayyad

1. CHAPTER 6
REMOTE SENSING,GPS AND GIS

2. DEFINITION
The method of collecting and
interpreting the information
of terrain and the object
without being in physical
contact with the object.

3. OBJECTIVE OF REMOTE SENSING
Object of remote sensing is
to collect and interpret
information about terrain
and other object from a
distance without being in
physical contact with the
object.

4. Electromagnetic radiation or EMR is the term used to
describe all of the different types of energies
released by electromagnetic processes.
Visible light is just one of many forms of
electromagnetic energy. Radio waves, infrared light
and X rays are all forms of electromagnetic radiation.
Remote sensing technologies rely on a variety of
electromagnetic energy. Sensors detect and measure
electromagnetic energy in different portions of the
spectrum.
Therefore it is important to understand the
fundamentals of electromagnetic radiation.
ELECTROMAGNETIC ENERGY/RADIATIONS(EMR)

5. ELECTROMAGNETIC ENERGY/RADIATIONS(EMR)
• The foundation of remote sensing technology is
based on the measurement and interpretation of the
patterns of EMR.
• EMR is a dynamic form of energy. EMR transmit
cross space in the wave form and in the speed of
light.
• The whole range of EMR is called spectrum.
• EMR is characterized by wavelength and frequency.
Different wavelengths or frequencies indicates
different portion of EMR.

6. ELECTROMAGNETIC ENERGY/RADIATIONS(EMR)
• EMR interact with atmosphere. The
atmosphere causes significant absorption
and/or scattering of the wavelength, such as
Rayleigh (molecular) scattering, Mie (non-
molecular) scattering, and non-selective
scattering.
• EMR also interact with the surface materials in
the form of absorption, reflection, and
transmission.
• Consider the reasons of interaction between
EMR and the atmosphere, atmospheric windows
will have to be used for remote sensor design
and ground information detection.

7. Electromagnetic Radiation (EMR)
• is radiated by atomic particles at the source
(the Sun),
• propagates through the vacuum of space at the
speed of light,
• interacts with the Earth's atmosphere,
• interacts with the Earth's surface,
• interacts with the Earth's atmosphere once
again, and
• finally reaches the remote sensors where it
interacts with
various optical systems and detectors.
ELECTROMAGNETIC ENERGY/RADIATIONS(EMR)

8. PRINCIPLE OF REMOTE SENSING

9. PRINCIPLE OF REMOTE SENSING

10. PRINCIPLE OF REMOTE SENSING

11. PRINCIPLE OF REMOTE SENSING

14. SYSTEMS OF REMOTE SENSING
SYSTEMS OF
REMOTE
SENSING
ACTIVE SYSTEM
PASSIVE SYSTEM

15. ACTIVE SYSTEM
The system in which
irradiance from artificially
generated energy sources
like radar is used it is called
as Active system of remote
sensing

16. PASSIVE SYSTEM
The system in which the sun
and earth’s material is used
as natural source so as to
radiate electromagnetic
energy of variable wave
length it is called as Passive
system of remote sensing

17. APPLICATIONS OF REMOTE SENSING
i) Land use or Land cover analysis: Remote sensing techniques are
useful for taking images of large area quickly, and it is cheaper
than ground surveying.
ii) Disaster management: In case of earthquakes, landslides,
volcanic eruptions and floods and natural hazards, remote
sensing can prevent and minimize the damage by analysing the
geological formation of the area, thereby identifying the risk
prone areas. It is possible to give specific warning of certain
natural hazards and assess the damage caused and thereby help
in the rescue and aid operations.

18. APPLICATIONS OF REMOTE SENSING
iii) Environment:
Remote sensing is useful in weather forecasting.
May aspects of ocean becoming better known through remote
sensing techniques.
Pollution in the form of oil spills and thermal plumes can easily
be monitored.
Study about Ozone layer depletion and global warming can be
possible by using remote sensors.

19. APPLICATIONS OF REMOTE SENSING
1.Silting of storage reservoirs harbors etc. – Remote sensing technique
that makes use of satellite imagery gives idea about the silting of
reservoir qualitatively and to some extent quantitatively.
2. Location of Percolation Tanks – The exact location of percolation
tanks can be carried out with the help of remote sensing technique,
keeping in view that the site required for location of percolation tanks
should be on permeable foundations.
3. Revision of existing topo sheets - The rapid revision and updating of
existing topo (graphical) sheets can be carried out speedily with the
help of aerial photography and satellite imagery.

20. APPLICATIONS OF REMOTE SENSING
4. Alignment of new highways and rail routes – The location of most
economical alternative sites for such works can very well be carried out
speedily by making use of aerial photographs and satellite imagery.
5. Location of Bridge site: The existing foundation condition along the
proposed bridge construction site can be ascertained with the help of
aerial photographs and or satellite imagery.

21. APPLICATIONS OF REMOTE SENSING
6.Location of Dam sites: For gravity, geological investigations of the existing
rock in and around the proposed dam site can be carried out by aerial
photographs and or satellite imagery. Geological features such folds, faults,
dykes, fractures etc. can be determined by the remote sensing technique.
7. Tunneling: Remote sensing i.e. aerial photography and or satellite imagery
of the area helps in furnishing all such information and thus ensures the
safety of tunnel during its construction stages.
8. Seepage losses in canals: Monitoring of soil moisture in and around the
canal system can be possible by remote sensing technique i.e. by careful
study of aerial photographs and satellite imagery of such areas.

22. GLOBAL POSITIONING SYSTEM (GPS)
The Global Positioning System (GPS) is a
satellite-based radio navigation system
owned by the US.
 It is a space-based utility that provides
users with positioning, navigation, and
timing (PNT) services. The Global
Positioning System is a made up of a
network of 24 satellites placed into orbit by
the U.S. Department of Defense.
The system was originally intended for
military applications, but in the 1980s, the
US government made the system available
for civilian use.

23. The U.S. Air Force develops, maintains,
and operates the space and control
segments.
GPS works in any weather conditions,
anywhere in the world, 24 hours a day.
There are no subscription fees or
setup charges to use GPS.
GLOBAL POSITIONING SYSTEM (GPS)

24. COMPONENTS OF GPS
SEGMENTSOFGPS
SPACE SEGMENT
CONTROLE
SEGMENT
USER SEGMENT

25. COMPONENTS OF GPS
The space segment consists of 24
satellites, each in its own orbit about
11,000 nautical miles above the Earth.
The control segment consists of
ground stations (five of them, located
around the world) that make sure the
satellites are working properly.
The user segment consists of
receivers, which you can hold in your
hand or mount in your car.

26. SPACE SEGMENT
The complete GPS space system includes 24
satellites. The orbits of these are 20187 km above
the Earth.
Each one takes 12 hours to go around the Earth
once (one orbit).
Each satellite is equipped with an accurate clock to
let it broadcast signals coupled with a precise time
message.

27. SPACE SEGMENT
The clocks keep accurate time to within three
nanoseconds.
Satellites are positioned so that we can receive
signals from six of them nearly 100 percent of the
time at any point on Earth. You need that many
signals to get the best position information.

28. CONTROLE SEGMENT
The GPS Control Segment (also referred to as Ground
Segment or Operational Control System) is the
responsible for the proper functioning of the GPS system.
The Control Segment consists of four major subsystems:
1.Master Control Station (MCS)
2. Backup Master Control Station
3. Network of four ground antennas (GAs),
4.Network of globally-distributed monitor stations (MSs).

29. USER SEGMENT
GPS User Segment consists of the GPS receivers
and the user community.
GPS receivers detect, decode, and process GPS
satellite signals.
A typical GPS receiver consists of an antenna
(whose position the receiver reports), a pre-
amplifier, radio signal microprocessor, control
and display device, data recording unit, and
power supply.

30. USER SEGMENT
The receivers convert GPS signals into
position, velocity, and time estimates. A
minimum of four satellites are required
to compute the four dimensions of X, Y, Z
(position) and Time.

31. USER SEGMENT
They can be hand carried or installed on
aircraft, ships, tanks, submarines, cars, and
trucks.
The typical hand-held receiver is about the
size of a cellular telephone. Some GPS
receivers have memory to store position data
points and the velocity of the antenna.
This information may be uploaded into a
personal computer or workstation, and then
used in GIS software database.

32. WORKING OF GPS
The ground unit receives the satellite signal
which takes a measurable amount of time to
reach the receiver.
The difference between the time the signal is
sent and the time it is received, multiplied by
the speed of light, enables the receiver to
calculate the distance to the satellite.

33. WORKING OF GPS
To measure precise latitude, longitude, and
altitude, the receiver measures the travel
times from at least four satellites to get to the
receiver.
An ordinary, hand held GPS receiver can
estimate the position anywhere on or above
the Earth’s surface to within about 5 m.

34. WORKING OF GPS
Even greater accuracy can be obtained
with corrections calculated by a GPS
receiver at a known fixed location; a
procedure called Differential GPS (DGPS).
More elaborate receivers have the ability
to receive data from and transmit data to
other GPS Tracking Devices; a technique
called real-time differential GPS that may
be used to considerably increase the
accuracy of position finding.

35. PROCEDURE OF GPS FIELD SURVEY
Receiver setup
Antenna setup
Height of instrument
measurements
Field processing and verification
Field GPS observation recording

36. PROCEDURE OF GPS FIELD SURVEY
A. Receiver setup
GPS receiver shall be set up in accordance with manufacturer’s specification prior to
beginning any observation.
To eliminate any possibility of missing the beginning of the observation session, all
equipment should be set up with power supplied to the receivers at least 10 minutes
prior to the beginning of the observation session.
Most receivers will lock-on to satellites within 1-2 min of powering up.

37. PROCEDURE OF GPS FIELD SURVEY
B. Antenna setup.
 All tribrach used on a project should be calibrated and adjusted prior to beginning each
project.
 Dual use of both optical plummets and standard plumb bobs is strongly recommended
since centering errors represent a major error source in all survey work, not just GPS
surveying.

38. PROCEDURE OF GPS FIELD SURVEY
C. Height of instrument measurements.
 Height of instrument (HI) refers to the correct measurement of the distance of the GPS
antenna above the reference monument over which it has been placed.
 HI measurements will be made both before and after each observation session.
 The HI will be made from the monument to a standard reference point on the antenna
 These standard reference point for each antenna will be established prior to the
beginning of the observation so all observers will be measuring to the same point.
 All HI measurements will be made in meters. HI measurements shall be determined to
the nearest millimeter in metric units. It should be noted whether the HI is vertical or
diagonal

39. PROCEDURE OF GPS FIELD SURVEY
D. Field GPS observation recording procedures.
 Field recording books, log sheet, or log forms will be completed for each station
and/or session. Any acceptable recording media may be used.
 For archiving purpose, standard bound field survey books are preferred. However,
USACE Commands may require specific recording sheet/forms to be used in lieu of a
survey book.
 The amount of record keeping detail will be project-dependent.
 Low-order topographic mapping points need not have as much descriptive information
as would have for permanently marked primary control points

40. PROCEDURE OF GPS FIELD SURVEY
D. Field GPS observation recording procedures.
The following typical data may be included on these field log records:
1) Project, construction contract, observer(s) name(s), and/or contractor firm and
contract number.
2) Station designation.
3) Station file number.
4) Date, weather conditions, etc.
5) Time, start/stop session (local and UTC).
6) Receiver, antenna, data recording unit, and tribrach make, model, and serial numbers.
7) Antenna height: vertical or diagonal measure in inches (or feet) and meters.
8) Space vehicle designations (satellite number).
9) Sketch of station location.
10) Approximate geodetic location and elevation.
11) Problems encountered.

41. PROCEDURE OF GPS FIELD SURVEY
E. Field processing and verification.
 It is strongly recommended that GPS data processing
and verification be performed in the field where
applicable.
 This is to identify any problem that may exist which
can be corrected before returning from the field.

42. APPLICATION OF GPS
Map making
Site selection
Mineral exploration
Environmental impact studies
Land use planning and
management
Natural hazard mapping or
assessment
Water resources availability
Road network analysis and
planning

43. GEOGRAPHIC INFORMATION SYSTEM (GIS)
GIS is a system that collects, displays,
manages and analyzes geographic
information.
A geographic information system (GIS)
is a system designed to capture, store,
manipulate, analyze, manage, and
present all types of geographical data.

44. GEOGRAPHIC INFORMATION SYSTEM (GIS)
Surveyors use GIS to manage the
entire planning aspect of
a surveying project. GIS provides the
tools necessary to research, develop,
implement, and monitor the progress
of a project and manage site location,
environmental impact mitigation,
economic analysis, and other critical
facts.

45. COMPONENTS OF GIS
Hardware
Software
Data
People

46. COMPONENTS OF GIS
Hardware
 It includes CPU of computer
it is attached with storage
device.
 Devices like digitizer and
scanner are used to convert
data which is in form of
maps and documents to
digital form and send them
to computer.

47. COMPONENTS OF GIS
Software
 The GIS software includes the programs and
user interface for driving the hardware.
 It is essential to generate , store, analyse ,
manipulate and display geographic
information or data
 The basic functions of software should offer
data capture, data management ,data
analysis and visualization.

48. COMPONENTS OF GIS
Soft wares used in GIS

49. COMPONENTS OF GIS
Data
 The most important component of GIS is
data.
 Geographic data and related tabular data can
collected in house, compiled to custom
specifications and requirements or
occasionally purchased from commercial data
provider
 GIS involves two geographic data
components-
Spatial data
Attribute data

50. COMPONENTS OF GIS
Data
 Spatial data-
It describes the absolute and relative
location of geographic feature . It relates to the
geometry of spatial feature.
 Attribute data-
It describes characteristics of spatial feature.
These are often referred to as tabular data. It
gives information about spatial features.

51. COMPONENTS OF GIS
Data
 Spatial data-
It describes the absolute and relative
location of geographic feature . It relates to
the geometry of spatial feature.
 Attribute data-
It describes characteristics of spatial
feature. These are often referred to as
tabular data. It gives information about
spatial features.

52. APPLICATION OF GIS
Map making
Site selection
Mineral exploration
Environmental impact studies
Land use planning and
management
Natural hazard mapping or
assessment
Water resources availability

53. SOURCES OF ERROR IN GIS
Error due to source data
Error occurring due to data input
Error in data storage
Error in output application
Error in data analysis and
manipulation

54. SOURCES OF ERROR IN GIS
A. Error due to source data:
1. Geometrical and sematic error in compilation of
source maps
2. Inaccuracy in source data
3. Error due to source data being out of date
4. Inaccuracy due to the range character of natural
boundaries
5. Limitation of survey equipment
Geometrical and sematic error

55. SOURCES OF ERROR IN GIS
B. Error due to data input:
1. Error in Attribute data entry
2. Error due to operation mistakes
C. Error in data storage:
1. Error due to limited precision with which co-
ordinates and other numerical data are stored
2. Error arising from rasterization
Conversion from vector to raster point data

56. SOURCES OF ERROR IN GIS
D. Error in data analysis and manipulation:
1. Error due to incorrect formula used
2. Error due to map overlay
E. Error in output application:
1. Error due to limitation of output device
2. Incorrect application of GIS products
Error due to map overlay

57. Thank You!