Kerala State Syllabus 10th Standard Social Science Notes Chapter 6 Eyes in the Sky and Data Analysis
Our ancestors made maps after collecting information about the surface of the earth and survey of earth’s surface which lasted for a long time. Aerial photography which developed later made map making quite easy. Satellite remote sensing and geographical information system which developed in the 1960’s as a result of the progress in science and technology paved the way for map making efficient and fast. The chapter helps you to understand how the launching of satellites and modern computer softwares help in the analysis of geophysical data.
→ Remote sensing : The method of collecting information about an object or phenomenon without actual physical contact.
→ Scanners : Sophisticated equipments that can detect electromagnetic radiation.
→ Sensors : The instruments used for data collection through remote sensing.
→ Active Remote Sensing : Remote sensing made with the help of artificial sources of energy is known as active remote sensing.
→ Passive Remote Sensing : Remote sensing carried out with the help of solar energy is known as passive remote sensing.
Platform : The carrier on which sensors are fixed is platform.
→ Terrestrial Photography : The method of obtaining earth’s photographs using cameras from the ground.
→ Aerial Remote Sensing : The method of obtaining photographs of the earth’s surface continuously from the sky using cameras mounted on aircrafts.
→ Satellite Remote Sensing : The process of collecting information using sensors fitted on artificial satellites is called satellite remote sensing.
→ Stereoscope: The instrument used for obtaining three dimensional view from the stereo pairs is called stereoscope.
→ Stereo pair: Two aerial photographs of adjoining areas or two adjacent aerial photographs with overlap.
→ Overlap: Each aerial photograph contains about 60% of the area shown in the previous photograph is termed as overlap.
→ Stereoscopic vision : The three dimensional
view obtained while viewing a stereo pair through a stereoscope. ‘
→ Geostationary satellites : Artificial satellites that orbit the earth at a height of about 36000 km in accordance with the earth’s rotation.
→ Sun Synchronous satellites: Artificial satellites that revolve around the earth along poles at a height of 900 km from the earth’s surface.
→ Spectral Signature : The amount of reflected energy by each object.
→ Spatial Resolution : The size of the smallest object on the earth’s surface that a satellite sensor can distinguish.
→ Geographic Information System : Geographic Information System is a computer based information management system by which data collected from the sources of information like maps, aerial photographs, satellite imageries, tables and surveys are incorporated into the cqmputer using softwares, which are retrieved, analyzed and displayed in the form of maps, tables and graphs.
→ Spatial Data : Each feature on the earth’s surface has its own latitudinal and longitudinal location. Such information is known as spatial data.
→ Attributes: The additional information about the characteristics of each spatial data on the earth’s surface are called attributes.
→ Layers : The thematic maps prepared and stored in Geographic Information System for analytical purpose are called layers.
→ Network Analysis : GIS analysis that deals with linear features on a map such as roads, railway and rivers.
→ Buffer Analysis : GIS analysis used for analyzing activities around a point feature or at a definite distance along a linear feature.
→ Overlay Analysis : GIS analysis used to identify the interrelationship of various surface features on earth and the changes they have undergone over a period of time.
→ Global Positioning System : A system using signals received from the artificial satellites to display the latitude, longitude, height and time of a place.
→ IRNSS : Indian Regional Navigation Satellite System is the satellite based navigation system developed by India as an alternative to GPS. It g is designed to provide accurate position information service.