2. WHAT IS REMOTE
SENSING
• Remote sensing is a technology by
virtue of which characteristics of
objects can be measured or analysed
without direct contact.
• Electro magnetic radiation is used as
source of data.
• Vehicle carrying sensor is called
platform.
3. ROLE OF REMOTE SENSING
• Sensing of remote objects with fine resolution.
• Transmission of sensor energy to earth surfaces through atmosphere.
• Detection of energy by sensor after retrieval from earth targets.
• Processing and analysis of data for desired results.
4. SENSOR SIGNIFICANCE
• PASSIVE SENSOR
Does not have their own source of radiation.
Sensitive to only radiation from natural origin.
• ACTIVE SENSOR
Have their radiation source.
Radar and Lidar
5. RESOLUTION
REFERENCES
• SPATIAL RESOLUTION
Measure of the accuracy or detail
of a graphic display.
Expressed as dots per inch, pixels
per line, lines per millimeter.
Concern the size of resolution cell
on ground in the direction of flight
and across.
6. RESOLUTION CONT.…
• SPECTRAL RESOLUTION
Ability of a sensor to define fine wavelength
intervals.
Finer the spectral resolution, the narrower the
wavelength range for a particular band.
Black and white film records wavelengths
extend much all of the visible portion of the
electromagnetic spectrum.
7. RESOLUTION
CONT…
• TEMPORAL RESOLUTION
Amount of time needed to revisit
and acquire data for the exact
same location.
Amount of time depends on the
orbital characteristics of the sensor
platform as well as sensor
characteristics.
9. VISUAL REMOTE SENSING
• Eyes passively senses the radiation reflected
or emitted from the object.
• Sensors in this example are the two types of
photosensitive cells, known as the cones and
the rods, at the retina of the eyes.
• Cones are responsible for colour vision.
• Rods are sensitive only to the total light
intensity.
10. OPTICAL REMOTE SENSING
• Make use of near infrared and short infrared
sensor to form images.
• Solar radiation targets of earth is detected
and analysed.
• Intensity, frequency and polarization
technique is used
11. SATELLITE REMOTE SENSING
• Satellites are usually put into space to monitor resources.
• Track animal migration, locate mineral deposits, watch agricultural crops for weather
damage.
• Able to monitor areas in which the climate is very harsh or impossible to reach by land.
12. RADAR REMOTE
SENSING
• Active microwave
sensors is RADAR
• Sensor transmits a microwave
(radio) signal towards the target
and detects the backscattered
portion of the signal.
13. ACOUSTIC REMOTE
SENSING
• Ultrasound (acoustic) and radar tide
gauges measure sea level, tides and
wave direction in coastal and
offshore.
• Passive sonar, listening for the sound
made by another object (a vessel, a
whale etc.) is used.
• Active sonar, emitting pulses of
sounds and listening for echoes, used
for detecting, ranging and
measurements of underwater objects
and terrain.
14. INFRARED REMOTE SENSING
• Radiations are emitted from warm objects such as the Earth's surface.
• Measurements of the earth's land and sea surface temperature.
• Thermal infrared remote sensing is also often used for detection of forest fires.
15. IMAGE PROCESSING IN REMOTE SENSING
• INPUT DATA
Digital data(multispectral scanner) is converted from HDDT (high density digital tape) to CCT (computer compatible tape).
Analog data digitized by an image scanner or drum scanner into digital image data.
• RECONSTRUCTION
Correction of radiometry and geometry should be undertaken in the process of preprocessing.
• TRANSFORMATION
Spatial and geometric transformation and data compression is required to generate a thematic map.
• CLASSIFICATION
Labeling, segmentation and matching techniques are used for image classification.
• OUTPUT
Analog output such as film or color copy and digital output in the form of a database are taken as output.
16. CONCLUSION
• The development and evolution of instruments and research mission of remote sensing occurred in
quite homogenous and regular manner.
• The rapid introduction of microwave sensing methods and means into airspace observations in last
10-15 years better consequences.
• Physical fundamental of remote sensing will help specialists in various geophysical disciplines-
meteorologist, geologists, soil scientist and oenologists.
• Joint efforts of specialist in various geophysical directions will become witness of new surprising
discoveries directed at studying earth.