Remote sensing• Remote sensing is the collection of information about an object without being in direct physical contact with the object.• The processes of collecting information about Earth surfaces and phenomena using sensors not in physical contact with the surfaces and phenomena of interest. 3
Some remote sensers Remote Sensing & GIS Applications Directorate
Steps in remote sensing• A – Source• B - Atmospheric interaction• C – Target• D – Sensor• E - Receiving unit:• F - Processing unit• G - Information system• H – Information
Optical remote sensing In optical remote sensing , the sensors can only record the radiation in visible bands, near infrared and short wave infrared bands. Depending on the number of spectral bands used, optical remote sensing can be classified into following divisions: 1. Multispectral imaging system 2.Superspectral Imaging Systems
Thermal remote sensingThermal infrared radiation refers to electromagnetic waves with a wavelength of between 3.5 and 20 micrometers.Nowadays, both multi- and hyperspectral thermal sensors are used
1 mm to 1 m of electromagnetic spectrum Microwave sensing encompasses both active and passive forms of remote sensing Longer wavelength microwave radiation can penetrate through cloud cover, haze, dust, and all but the heaviest
Platforms Platforms are: •Ground based •Airborne •Spaceborne Sensing from 1 meter to 36,000 km height 15
Natural Resource Management ◦ Habitat analysis ◦ Environmental assessment ◦ Pest/disease outbreaks ◦ Impervious surface mapping ◦ Lake monitoring ◦ Hydrology ◦ Landuse-Landcover monitoring ◦ Mineral province ◦ Geomorphology ◦ Geology• National Security -Targeting - Disaster mapping and monitoring -Damage assessment -Weapons monitoring -Homeland security -Navigation -Policy 18
GIS (GEO GRAPHICAL INFORMATIONSYSTEM) Geographic Information System (GIS) is a computer based information system A system for capturing, storing, checking, integrating, manipulating, analysing and displaying data which are spatially referenced to the Earth.
What GIS Does ? Mapping and *cartography Query Select Distance: Buffers Overlay Clip Merge Raster analysis 3D Continued….
Techniques used in GIS Relating info. from different sources Data capture Data integration Projection and registration Data structures Data modeling
Advantages GIS• Can cope with larger amounts of data• Can cover large study areas (the whole world if necessary)• Can cope with unlimited and frequent edits and changes• More robust and resistant to damage• Faster and more efficient• Requires less person time and money