SCIENCE TECHNOLOGY

LESSON 5

REVIEWElectromagnetic 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.

GROUND TRUTHING – BALTIMORE, MD

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 areasBlue/Purple: concrete, roads, cities,

other impervious surfacesBlue/Black: waterBurnt/Brownish Orange: mix of

deciduous trees and lawns; suburban areas

ACTIVITY:GROUND TRUTHING

Group work – 6 groupsPass out worksheets by groupCompare 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

Ground Truthing Both Remote Sensing

Tell how Ground Truthing is different from remote sensing

Tell how they are alike Tell how Remote Sensing is different from ground truthing

QUESTIONS & DIAGRAM

How can remote sensing be used

in the future

What technology do scientists still need to invent?