1. “In Pursuit Of Global Competitiveness”
Government College Of Engineering,
REMOTE SENSING &
2. Remote Sensing is:
“Theart and science of obtaining information
about an object without being in direct
contact with the object”.
There is a medium of transmission involved.
remote sensing systems have four
types of resolution:-
Spatial Resolution -- what size we can resolve.
Spectral Resolution -- what wavelengths do we
Radiometric Resolution -- degree of detail
Temporal Resolution -- how often do we
7. Energy Source or Illumination
Radiation and the Atmosphere
Interaction with the Target (C)
Recording of Energy by the
Transmission, Reception, and
Interpretation and Analysis (F)
8. Remote Sensing is unique in that it
can be used to collect data, unlike
other techniques, such as thematic
cartography, geographic information
systems, or statistics that must rely
on data that are already available.
9. The principal advantages of remote
sensing are the speed at which data
can be acquired from large areas of
the earth’s surface, and the related
fact that comparatively inaccessible
areas may be investigated in this
10. Based on Range of Electromagnetic
1. Optical Remote Sensing.
2. Thermal Remote Sensing.
3. Microwave Remote Sensing.
Based on the source of the energy:-
1. Active remote sensing.
2. Passive remote sensing.
11. Optical Remote Sensing:-
The optical remote sensing devices operate
in the visible, near infrared, middle
infrared and short wave infrared portion of
the electromagnetic spectrum.
These devices are sensitive to the
wavelengths ranging from 300 nm to
12. Thesensors, which operate in
thermal range of electromagnetic
spectrum record, the energy
emitted from the earth features in
the wavelength range of 3000 nm to
5000 nm and 8000 nm to 14000 nm.
13. A microwave remote sensor records
the backscattered microwaves in the
wavelength range of 1 mm to 1 m of
Mostof the microwave sensors are
active sensors, having there own
sources of energy.
14. Active remote sensing:-
Active remote sensing uses an artificial
source for energy.
For example the satellite itself can send a
pulse of energy which can interact with the
In active remote sensing, humans can control
the nature (wavelength, power, duration) of
the source energy. Active remote sensing can
be carried out during day and night and in all
15. Passive remote sensing depends on a
natural source to provide energy.
Thesun is the most powerful and
commonly used source of energy for
passive remote sensing.
Thesatellite sensor in this case records
primarily the radiation that is reflected
from the target.
Landsat satellite sensors are one of the
most popular remote sensing systems, the
imagery acquired from these are widely
used across the globe.
NASA’s Landsat satellite programme was
started in 1972. It was formerly known as
ERTS (Earth Resource Technology
18. SPOT (System Pour Observation
Terre) was developed by the French
The first satellite of SPOT
mission, SPOT-1 was launched in
1986. It was followed by SPOT-2 (in
1990), SPOT-3 (in 1993), SPOT-4 (in
1998) and SPOT-5 (in 2002).
19. The Indian Remote Sensing
programme began with the
launch of IRS-1A in 1988.
After that IRS-1B (1999), IRS-1C
(1995) and IRS-1D (1997) was
20. Provides a regional view (large areas).
Provides repetitive looks at the same
Remote sensors "see" over a broader.
portion of the spectrum than the human
Provides geo-referenced, digital, data.
Some remote sensors operate in all
seasons, at night, and in bad weather.
21. • Expensive to build and
• Measurement uncertainty can
• Data interpretation can be