“In Pursuit Of Global Competitiveness”Government College Of Engineering, Aurangabad. REMOTE SENSING & IT’S APPLICATION Created By- Nikhil Pakwanne 1
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.
All remote sensing systems have four types of resolution:-Spatial Resolution -- what size we can resolve.Spectral Resolution -- what wavelengths do we use.Radiometric Resolution -- degree of detail observed.Temporal Resolution -- how often do we observe.
Energy Source or Illumination (A) Radiation and the Atmosphere (B) Interaction with the Target (C) Recording of Energy by the Sensor (D) Transmission, Reception, and Processing (E) Interpretation and Analysis (F) Application (G)
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.
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 way.
Based on Range of Electromagnetic Spectrum:-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.
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 3000 nm.
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.
A microwave remote sensor records the backscattered microwaves in the wavelength range of 1 mm to 1 m of electromagnetic spectrum. Mostof the microwave sensors are active sensors, having there own sources of energy.
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 target. 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 weather conditions.
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:- 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 Satellite) programme.
SPOT (System Pour Observation Terre) was developed by the French National Centre. 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).
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 launched.
Provides a regional view (large areas). Provides repetitive looks at the same area. Remote sensors "see" over a broader. portion of the spectrum than the human eye. Provides geo-referenced, digital, data. Some remote sensors operate in all seasons, at night, and in bad weather.
• Expensive to build andoperate! • Measurement uncertainty canbe large. • Data interpretation can bedifficult.
Agriculture:- Crop type classification. Crop condition assessment. Crop yield estimation. Mapping of soil characteristic. Soil moisture estimation.
Geology:- Lithological mapping. Mineral exploration. Environmental geology. Sedimentation mapping and monitoring. Geo-hazard mapping. Glacier mapping.
Urban Planning:- Land parcel mapping. Infrastructure mapping. Land use change detection. Future urban expansion planning.
Hydrology:- Watershed mapping and management. Flood delineation and mapping. Ground water targeting. Land Use/Land Cover mapping:- Natural resource management. Wildlife protection. Encroachment.
Forestry And Ecosystem:- Forest cover and density mapping. Deforestation mapping. Forest fire mapping. Wetland mapping and monitoring. Biomass estimation. Species inventory.
Ocean applications:- Storm forecasting. Water quality monitoring. Aquaculture inventory and monitoring. Navigation routing. Coastal vegetation mapping. Oil spill.