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Science technology lesson 5. review. Electromagnetic Spectrum (definition):. The range of energy which contains parts or bands: visible light, infrared, ultraviolet, microwave (radar), gamma ray, x-ray and radio.
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review • Electromagnetic Spectrum (definition): • The range of energy which contains parts or bands: visible light, infrared, ultraviolet, microwave (radar), gamma ray, x-ray and radio. • Different parts of the EM Spectrum have different wavelengths and frequencies.
Review Cont. • Pixels (definition): • The smallest unit of a digital picture. • Satellite images are made up of a matrix of many pixels each with its own value. • Colors represent the reflected light energy.
IMAGE INTERPRETATION • Compare this satellite image to the view from an airplane window – write in notebook • List visual clues that help identify different kinds of land cover. • Hint: geometric shapes usually indicate human-made areas. • Image interpretation is the initial stage of land cover mapping • Remember ground truthing is a technique that uses field observations to determine the accuracy of a land cover map made from a satellite image.
Color code to image interpretation • Red: vegetation with high photosynthetic activity (growing grass or trees in full leaf) • Orange: Vegetation that is not currently photosyntheticaly active, lawns • Green: deciduous forest areas • Blue/Purple: concrete, roads, cities, other impervious surfaces • Blue/Black: water • Burnt/Brownish Orange: mix of deciduous trees and lawns; suburban areas
Activity:Ground Truthing • Group work – 6 groups • Pass out worksheets by group • Compare the ground data to their map for the same area and present their findings to the class • Using the satellite image, find other areas with the same spectral signature (i.e. same ground cover) • Do we need to adjust our class definition of Ground Truthing? Look at your definitions.
summarize • Why is ground validation (ground truthing) so important for interpreting satellite imagery?
Venn Diagram Foldable: Evaluate ground truthing & remote Sensing
Questions & Diagram What technology do scientists still need to invent?