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Resolution

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Resolution: sensor characteristic that affect what can be seen in an image Source: NASA Spatial resolution Spectral characteristics Temporal characteristics Sensor sensitivity SPATIAL RESOLUTION Spatial resolution refers to the amount of detail that can be detected by a sensor. It is the smallest unit measured; Images where only large features are visible are said to have coarse or low resolution. In fine or high-resolution images, small objects can be detected. Detailed mapping of land-use practices requires a much greater spatial resolution. Size of an image pixel in ground dimensions. Usually represented by the length of one side of a square (i.e., 30m resolution). The spatial resolution of passive sensors depends primarily on their Instantaneous Field of View (IFOV). The IFOV is the angular cone of visibility of the sensor (A) and determines the area on the Earth’s surface which is “seen” from a given altitude at one particular momen...
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Basic of Remote Sensing IV

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Sources of Electromagnetic Energy There are three main sources of  electromagnetic radiation that are used in  remote sensing:  Solar radiation (natural radiation from the  sun)  Terrestrial radiation (natural radiation  emitted by Earth's surface)  Artificial radiation (from a remote sensing  system) Solar Radiation The Sun yields a continuous spectrum of EM  energy. This Incident radiation can be reflected  from the Earth's surface. This process produces a large amount of  short wavelength energy (from 0.4 - 0.7 µm;  blue, green, and red light). It can also be emitted by the Earth's  surface. Such emitted radiation is typically  of a longer wavelength, in the middle and  far infra-red wavelengths. Interacts with the atmosphere and surface  materials (reflect, absorb).  Since the Sun has a much higher temperature  (6000 degrees K) than the Earth (303 degrees  K), so t...
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Basic of Remote Sensing

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Contents What is Remote Sensing? Need for Remote Sensing? Who uses Remote Sensing and Why? Remote Sensing :  The art & science of  acquiring, processing, and interpreting information (images and related data) about the Earth’s surface without  actually being in physical contact between the object and sensor. This is done by sensing & recording reflected or emitted energy  and processing, analyzing and applying that information. The images and related data are obtained from ground-based, air-or space- borne instruments that record the interaction between matter (target) and  electromagnetic radiation. " remotely" means using instruments (sensors) carried by platforms . Need For Remote Sensing Systematic data collection; Global coverage; Repeatability; Inaccessible areas – sometimes the only solution; Multi-purpose information Who Uses Remote Sensing & Why The geographer who looks for changes in the E...
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