Element Of Civil Engineering and surveying subject as per GTU syllabus 1st sem carry out all content. also usefull for general idea about civil branch.

1. SHREE SWAMI ATMANAND
SARASWATI INSTITUTE OF
TECHNOLOGY
Prepared By:-
Karm Balar

3.  Remote sensing – definition
 Concept of remote sensing
 History of remote sensing
 Advantages of remote sensing
 Disadvantages of remote sensing
 Principle of remote sensing
 Elements of remote sensing
 Remote sensing platform
 Remote sensing software

4. 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, area, or
phenomenon under investigation.
Remote sensing is the acquiring of data
about an object without touching it.

5. Human eye
Camera
Radiometer
Radar
Sonar
Laser
 Passive
 Active
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6. CONCEPT OF REMOTE SENSING
We perceive the surrounding world through our five
senses. Some senses (touch and taste) require the contact of our
sense organs with the object. However, we acquire much
information about our surrounding through the senses of sight and
hearing which do not require close contact between the sensing
organs and the external object.
The technical term ‘remote sensing’ was first used in in the
US in the 1960s. Technical term 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 wildely used.

7. HISTORY OF REMOTE SENSING
 Aerial photography is the original form of remote sensing (using visible
spectrum) started in 1909
 Aerial photographic reconnaissance was widely used after 1915 in WWI.
 Photogrammetric Engineering, the official monthly publication of the American
Society of Photogrammetry, was first published in 1934.
 Color infrared photography began 1931, then was widely used in agriculture
and forestry.
 Development of radar (1930-1940).
 During WWII, non-visible spectrum (infrared and radar) were used as tools in
remote sensing.
 After the first man-made satellite (Sputnik 1) was launched on 4 October 1957
by Soviet Union, remote sensing moved to outer space, ignited the Space Race
within the Cold War.

8.  The United States' Explorer 6 transmitted the first space photograph
of the Earth in August 1959.
 The first systematic meteorological satellite observation came with
the launch of the United States' TIROS 1 in 1960.
 Landsat 1 (originally called the Earth Resources Technology
 Satellite or ERTS) was the first satellite to collect data on the
Earth's natural resources. It was launched on 23 July 1972.
 Hyperspectral remote sensing emerged (1980s), widely used in
mineral, oil, etc. exploration.
 Since then, a large number and advanced types of remote sensing
systems have been developed.

9. ADVANTAGES OF REMOTE SENSING
 Satellite images are permanent records, providing useful
information in various wavelengths.
 Large area coverage enables regional surveys on a variety
of themes and indentification of large features.
 Repetitive coverage allows monitoring of dynamic themes
like water, agriculture etc.
 Easy data acquisition at different scales and resolution.
 Amenability of remotely sensed data for fast processing
using a computer.
 The images are analysed in the laboratory thus reducing
the amount oh firld work.
 Map revision at medium to small scales is economical and
faster

10.  Color composite can be prodused from three
individual band images, which provide better
details of the area than a single band image or
aerial photograph.
 Flods over a large region, or the forest fire can be
located from above and rescue planning can be
immediately arranged.
 The inaccessible areas like volcanic eruption,
failure of dam over river, etc. can be covered by
the remote sensing techniques to study the
intensity of disaster

11. DISADVANTAGES OF REMOTE SENSING
 Expensive for small areas, particularly for
one time analysis,
 Requires specialized training for analysis of
images.
 Data interpretation can be difficult
 need to understand theoretically how the instrument is
making the measurements
 need to understand measurement uncertainties
 need to have some knowledge of the phenomena you are
sampling

12.  Expensive to build and operate!!!!
 Measurement uncertainty can be large
 Powerful active remote sensing systeam,
such as radars or lasers that emit their own
EMR (electromagnetic radiation), can be
intrusive and affect the phenomenon being
investigated

13. PRINCIPLE OF REMOTE SENSING
 The sun and various artificial sources radiate electromagnetic energy of
variable wavelengths.
 All objects on the surface of the earth have spectral signatures. A spectral
signature of an object or ground surface is a values for the reflectance or
radiance the feature.
 The electromagnetic energy interacts with the earth’s surface and various
features like buldings, bared soil, grass, water,paved road, forest etc.
 The knowledge of spectral signature is essential for exploiting the potential of
the remote sensing techniques. This knowledge enable one to identify and
classify objects.

14. When radiation is incident on a surface, it is reflected,
adsorbed, 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. In view of these facts, one can identify the
material constituting the object from a spectral plot,
multiband photograph or any other record, which shows
enough details of its spectral reflection, absorption,
scattering or transmission properties

15. ELEMENTS OF REMOTE SENSING
 Energy Source or Illumination - the first requirement for
remote sensing is to have an energy source which illuminates
or provides electromagnetic energy to the target of interest.
 Radiation and the Atmosphere - as the energy travels from
its source to the target, it will come in contact with and interact
with the atmosphere it passes through. This interaction may
take place a second time as the energy travels from the target
to the sensor.
 Interaction with the Target - once the energy makes its way
to the target through the atmosphere, it interacts with the
target depending on the properties of both the target and the
radiation.

16.  Recording of Energy by the Sensor - after the energy has
been scattered by, or emitted from the target, we require a
sensor (remote - not in contact with the target) to collect and
record the electromagnetic radiation.
 Transmission, Reception, and Processing - the energy
recorded by the sensor has to be transmitted, often in electronic
form, to a receiving and processing station where the data are
processed into an image (hardcopy and/or digital).
 Interpretation and Analysis - the processed image is
interpreted, visually and/or digitally or electronically, to extract
information about the target which was illuminated.
 Application - the final element of the remote sensing process is
achieved when we apply the information we have been able to
extract from the imagery about the target in order to better
understand it, reveal some new information, or assist in solving a
particular problem.

17. REMOTE SENSING PLATFORMS

18. AIRPLAN-BASED