Introduce to remote sensing

1. History of remote
sensing

2. Definition
 obtaining information about an object without touching the object itself.
Or
 Remote sensing is the collection of information about an object without
being in directphysical contact with the object.
Or
 Remote sensing is the process of detecting and monitoring the physical
characteristics of an area by measuring its reflected and emitted radiation
at a distance without any contact to the object.

3. History of remote sensing
 1814 Joseph Niepce achieves first
photographic image with camera obscura -
however, the image required eight hours of
light exposure and later faded.
 1837 Louis Daguerre's first daguerreotype
the first image that was fixed and did not
fade and needed under thirty minutes of
light exposure.

4.  Photography (as we know it) - "light drawing' - invented in theearly 1800’s
World oldest photo

5.  From the beginning, the potential of aerial photography for topographic
mapping was clear
 Early platforms used for aerial photos included:
• balloons
• pigeons
• kites

6.  San Francisc after the earthquake and fire of 1906 (bottom photo) - kite photos.
Aierial Photography

7.  The advantages afforded by aerial surveillance
quickly become apparent during First World War.

8.  The first nonmilitary earth observing satellite was
designed to transmit television pictures back to earth
showing broad weather patterns (1960).

9.  A new era in remote sensing began on July 23, 1972, when the United States launched
the first earth observation satellite dedicated primarily for land observation, called Earth
Resources Technology Satellite (ERTS-1).
 This was the first satellite available for systematic and repetitive observation of the earth
surface. With the launch of the second satellite in January, 1975, the name of the series
was changed to LANDSAT

10.  From the early 70's to the mid 80's, remote sensing promised much, but
had trouble fully delivering on that promise
 More open cooperation with researchers• Multiple satellite-based sensors
launched
• LANDSAT (monitoring land resources)
• AVHRR (monitoring meteorological conditions)
• SeaSat (oceanographic research using radar)
• TOMS (ozone mapping)

12. Process of remote sinsing
 A. Energy Source
 B. Radiation and the Atmosphere
 C. Interaction with the Object.
 D. Recording of Energy by the Sensor
 E. Transmission, Reception and Processing
 F. Interpretation and Analysis
 G. Application

13. Process of remote sensing

14.  (A) Energy Source or Illumination (Sun):
The first requirement for remote sensing is to have an energy source which
illuminates or provides electromagnetic energy to the target of interest.
 (B) 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
 (C) Interaction with the Target:
Energy interacts with the target depending on the properties of both the target
and the radiation.

15.  (D) Recording of Energy by the Sensor:
After the energy has been scattered by, or emitted from the target, we require a
sensor to collect and record the electromagnetic radiation
 (E) Transmission, Reception, and Processing:
The energy recorded by the sensor has to be transmitted in electronic form, to a
receiving and processing station where the data are processed.
 (F) Interpretation and Analysis:
The processed image is interpreted, visually or digitally or electronically, to
extractinformation about the target.

16.  (G) 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. Two major types of remote sensing
 Passive remote sensing
 active remote sensing
1. Passive
Measure naturally-available energy (eg.
thermal infrared radiation emitted from the
Earth 24 hours per day, but solar reflected
radiation only during solar day)

18. Two major types of remote sensing
• Active
Sensor emits radiation toward target
Reflected radiation in emitted bands are
detected and measured(eg. microwaves
emitted)

19. Application of remote sensing
Agriculture
 crop condition assessment
 crop yield estimation
 mapping of soil characteristics
 mapping of soil management practices
 compliance monitoring (farming practices)
 Monitoring of pests and Diseases

20. Forestry
 management agencies are inventory and mapping applications, collecting harvest
information, updating of inventory information for timber supply, broad forest type,
vegetation density and biomass measurements.
 Environmental monitoring conservation authorities are concerned with monitoring
the quantity, health, and diversity of the Earth's forests.

21. Hydrology
 Wetlands mapping and monitoring
 Soil moisture estimation.
 Snow pack monitoring/ delineation of extent,
 Measuring snow thickness,
 Determining snow-water equivalent,
 River and lake ice monitoring
 Flood mapping and monitoring
 Glacier dynamics monitoring (surge, ablation)
 River/delia change detection
 Drainage busin mapping and watershed modeling • Irrigation canal leakage detection
 Irrigation scheduling,
 Crop water estimation
 Monitoring of crop water stresses
 Canal water distribution and management

22. Sea ice
 ice concentration
 ice type/age/motion
 Iceberg detection and tracking
 Surface topography
 Tactical identification of leads: navigation: safe shipping routes/rescue
 Ice condition (state of decay)
 Historical ice and iceberg conditions and dynamics for planning purposes.
 Wildlife habitat

23.  Land use and land cover
 Natural resource management
 Wildlife habitat protection
 Baseline mapping for GIS input
 Urban expansion/encroachment
 Routing and logistics planning for seisnic/ exploration / resource activities
 Damage delineation (tornadoes, flooding, volcanic, seismic, fire)
 Legal boundaries for tax and property evaluation
 Target detection-identification of landing strips, roads, clearings, bridges,
land/water

24. Applications of remote sensing
 Weather Forecasting
Remote sensing is extensively used in
India for weather forecasting. It is also
used to warn people about impending
cyclones.

25.  Study of Natural hazards
Remote sensing can be used to study
damages caused by earthquakes,
volcanoes, landslides, floods and
melting of ice in polar regions. Many
times remote sensing will be helpful to
predict the occurrence of natural
hazards.
Applications of remote sensing

26.  It covers large area
 Remote sensing process makes it possible to gather information about the
inaccessible area when it is not possible to do ground survey like in
mountainous areas or foreignlands.
 Time: Since information about a large area can be gatheredquickly, the
techniques save time and efforts of human beings/ormass.
 Multi-disciplinary applications: The data gathered by remote sensing
process can be used by the users of different disciplines like, geology,
forestry land use etc.
Advantages of remote sensing

27. Advantages of remote sensing
 It Provides repetitive looks at the same area
 Easy to spot areas of tsunami, drought prone,cyclone hit areas and helps in
providing relief and rehabilition programme in the affected areas
 It can focus on areas where humans cannot reach.
ex.equitorial forest in the congo,africa.

28. Disadvantages of remote sensing
 Its too expensive
 Its not suitable for small areas
 Needs experts to extract data

29. Conclusion