23-11-2012, 12:17 PM
Remote Sensing
Remote sensing.ppt (Size: 859 KB / Downloads: 186)
Introduction to Remote Sensing:-
1.Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object.
2. Remote sensing observations provide data on earth’s natural resources in a spatial format. The remote sensing (RS) data has the advantage of synoptic view and large area coverage.
3.Remote Sensing and GIS techniques becomepotential and indispensable tools for solving many problems of civil engineering and terrain.
concept:-
Scientists of many disciplines are accustomed to studying data that cannot be observed through direct contact. Physicists and chemists, for instance, know a great deal about the structure of the atom, even though even the most high-powered microscope cannot make an atom visible to the human eye.
The objects of study for earth scientists are often similarly remote, though not necessarily because they are small.
history
The TR-1 reconnaissance/surveillance aircraft.
The 2001 Mars Odyssey used spectrometers and imagers to hunt for evidence of past or present water and volcanic activity on Mars.
Systematic aerial photography was developed for military surveillance and reconnaissance purposes beginning in World War I and reaching a climax during the Cold War with the use of modified combat aircraft such as the P-51, P-38, RB-66 and the F-4C, or specifically designed collection platforms such as the U2/TR-1, SR-71, A-5 and the OV-1 series both in overhead and stand-off collection.
The development of artificial satellites in the latter half of the 20th century allowed remote sensing to progress to a global scale as of the end of the Cold War. Instrumentation aboard various Earth observing and weather satellites such as Landsat, the Nimbus and more recent missions such as RADARSAT and UARS provided global measurements of various data for civil, research, and military purposes. Space probes to other planets have also provided the opportunity to conduct remote sensing studies in extraterrestrial environments, synthetic aperture radar aboard the Magellan spacecraft provided detailed topographic maps of Venus, while instruments aboard SOHO allowed studies to be performed on the Sun and the solar wind, just to name a few examples.
Remote Sensing software:-
Remote Sensing data is processed and analyzed with computer software, known as a remote sensing application. A large number of proprietary and open source applications exist to process remote sensing data.
TNTmips from MicroImages, PCI Geomatica made by PCI Geomatics, the leading remote sensing software package in Canada, IDRISI from Clark Labs, Image Analyst from Intergraph, and RemoteView made by Overwatch Textron Systems. Dragon is one of the oldest remote sensing packages still available, and is in some cases free.
Terrain Mapping and Analysis:-
Assessment of the performance of the terrain for specific developmental activities can be made through terrain evaluation. For this, terrain information can be acquired from RS data and by generating the Digital Terrain Model (DTM). A DTM is an ordered array of numbers representing the spatial distribution of terrain characteristics stored in a computer so as to enable the determination of any quantitative data pertaining to terrain. DTMS is useful in investigation of a number of alternative horizontal and vertical alignments of canals, roads, pipelines or corridors for any such applications.
Environment and Geology:-
Whether for irrigation, power generation, drinking, manufacturing, or recreation, water is one of our most critical resources. Image interpretation can be used in a variety of ways to help monitor the quality, quantity of water resources. It is well proven in exploring ground water prospect zones. One such example is Rajiv Gandhi Drinking Water Mission with help of remote sensing and GIS. Sediment pollution is often clearly depicted on aerial and space images. Materials that form films on the water surface, such as oil films, can also be detected through the use of aerial and satellite images. Normal colours or ultraviolet aerial photography is often employed for the detection of oil films on water.