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1. LAXMI INSTITUTE OF
TECHNOLOGY,SARIGAM.
PRESENTATION ON:
REMOTE SENSING.
GUIDED BY: PRESENTED BY:
BHAIRAV THAKUR, SHAIKH MOHD.AMIR N.
(ASSISSTANT PROFESSOR,
CIVIL DEPARTMENT, LIT).

2. DEFINITION:
• Remote sensing is the 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, ea or phenomenon under
investigation.
• Remote sensing is the acquiring of data about an
object without touching it.

3. CONCEPT OF REMOTE SENSING:
• Generally, remote sensing refers to the activities
of recording/observing/perceiving object or
events at far away places.
• In remote sensing, the sensors are not in direct
contact with the objects being observed.
• The information needs a physical carrier to
travel from objects/events to the sensors
through an intervening medium.
• The electromagnetic radiation is normally used
as an information carrier in remote sensing.

4. • The technical term ‘remote sensing’ was first used in the
United States in the 1960s.
• Technical terms like encompassed photogrammetry,
photo-interpretation and photo-geology also were emerged
with remote sensing.
• Since Landsat-1, the first earth observation satellite was
launched in 1972, remote sensing has become widely used.
• Remote sensing occurs at a distance from the object or
area of interest.
• Interestingly, there is not clear distinction about the
distance.
• It cold be 1m,1000m or more than 1000km, from the
object or area of interest.
• In fact virtually, all astronomy is based on remote sensing.
• The characteristics of an object can be determined using
reflected or emitted electromagnetic radiation from the
object.

5. APPLICATIONS(ADVANTAGES):
• Satellite images are permanent records, providing useful
information in various wavelengths.
• Large area coverage enables regional surveys on a variety
of themes and identification of large features.
• Repetitive coverage allows monitoring of dynamic
themes like water, agriculture, etc.
• Easy data acquisition at different scales and resolutions.
• A single remotely sensed image can be analyzed and
interpreted for different purposes and applications.
• The images are analyzed in the laboratory thus reducing
the amount of field work.
• Map revision at medium to small scales is economical
and faster.

6. LIMITATIONS:
• Expensive for small areas, particularly for one
time analysis.
• Requires specialized training for analysis of
images.
• Large scale engineering maps cannot be
prepared from satellite data.
• Aerial photographs are costly if repetitive
photographs are required to study the dynamic
features.

7. PRINCIPLE:

8. • The sun and various artificial sources radiate
electromagnetic energy of variable wavelengths.
• All objects on the surface of he earth have spectral
signatures. A spectral signature of an object or
ground surface feature is a set of values for the
reflectance or radiance of the feature.
• The electromagnetic energy interacts with the
earth’s surface and various features like buildings,
bared soil, grass, water, paved road, forest, etc.
• The response of ground surface materials to incident
radiations the reflectance and he energy emitted by
all objects as a function of their temperature and
structure is the emittance.the reflectance and
emittance determine the signatures.

9. • The knowledge of spectral signature is essential
for exploiting the potential of the remote sensing
techniques. This knowledge enables one to
identify and classify objects.
• When radiation is incident on a surface, it is
reflected, absorbed, scattered and transmitted.
All the processes are strongly dependent on the
wavelength of the incident radiation, as well as
the atomic and molecular structure of the
material.

10. ELEMENTS:

11. (A) Energy Source or Illumination
(B) Radiation and the Atmosphere
(C) Interaction with the Target
(D) Recording of Energy by the Sensor
(E) Transmission, Reception, and
Processing
(F) Interpretation and Analysis
(G) Application

12. • Energy source: The sun is the source of energy is
passive remote sensing. The sun produces
electromagnetic energy.
• Propagation of energy: The energy from the
source propagates through the atmosphere. The
atmosphere modifies the wavelength and spectral
distribution of energy to some extent.
• Interaction with target: The energy received by
the target interacts where it is either transmitted,
absorbed, scattered, emitted or reflected from the
target.
• Recording by sensor: The return signal is set to
the sensor which responds to all wavelengths.
Sensors are mounted on satellites.

13. • Transmission, Reception and Processing:
The energy recorded by the sensor has to be
transmitted, often in electronic form to a
receiving and processing station on the ground
where the data are processed into an images.
• Interpretation and analysis: The processed
image are interpreted, visually or digitally or
electronically to extract information about the
target of interest.
• Application: The information about the target
obtained from the remote sensing is made
available to the users in the desired form.

14. TYPES OF REMOTE SENSING:
• In respect to the type of energy resources,
remote sensing can be classified into two
categories:
▫ 1. passive remote sensing
▫ 2. active remote sensing

15. PASSIVE REMOTE SENSING:
• The sun provides a very
convenient source of energy
for remote sensing.
• The sun's energy is either
reflected, or absorbed and
then reemitted.
• Remote sensing systems which
measure energy that is
naturally available are called
passive sensors.
• Passive sensors can only be
used to detect energy when the
naturally occurring energy is
available.

16. ACTIVE REMOTE SENSING:
• The sensor emits radiation
which is directed toward the
target to be investigated.
• The radiation reflected from
that target is detected and
measured by the sensor.
• Advantages :- the ability to
obtain measurements anytime,
regardless of the time of day or
season.
• require the generation of a
fairly large amount of energy
to adequately illuminate
targets.
• E.g. a laser fluorosensor and
a synthetic aperture radar
(SAR)

17. REMOTE SENSING IN INDIA:
• After gaining independence in 1947, India
focussed on development of science and
technology.
• The Indian Committee for space
research(INCOSPAR) lead by Prof. Sarabhai was
a part of Tata Institute of Fundamental
Research(TIFR) lead by it director G.K.Menon.
• Dr. A.P.J.Abdul Kalam was amongst the initial
team of rocket engineers forming INCOSPAR.

18. • In 1962, INCOSPAR took the decision of setting up Thumba
Equatorial Rocket Launching station at Thumba also known
as Trivandrum in South India.
• On 15th August INCOSPAR was reconstituted and Indian
Space Research Organization(ISRO) was created under the
department of Atomic Energy to conduct space research and
applications.
• In 1972, the Indian Government set up space commission and
entrusted Department Of Space (DOS) with responsibility for
conducting India’s space activities.
• While ISRO is the main developer and launcher of the satellite
system, it is complicated by two separate projects
INSAT(Indian National Satellite for Telecommunications)
and IRS(Indian Remote Sensing Satellite)for earth
observation.
• DOS is also the nodal agency for Physical Research
Laboratory(PRL) which conducts research in the area of
Space Science and National Remote Sensing Agency(NRSA)
which deploys modern remote sensing techniques for natural
resource survey.

19. • At present, nine centers of ISRO are responsible
for various activities:
1. VSSC(Vikram Sarabhai Space Center).
2. Liquid Propulsion Systems Center.
3. ISRO Satellite Center.
4. SHAR Center.
5. ISRO’s Inertial System Unit.
6. ISRO Telemetry, Tracking & Command
Network(ISTRAC).
7. Space Application Center(SAC).
8. INSAT Master Control Facility(MCF).
9. Development and Educational Communications
Unit(DECU).

20. INDIAN REMOTE SENSING SATELLITES: