introduction to remote sensing example applications and principles
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Introduction to Remote Sensing Example Applications and Principles Exploring Images with MultiSpec User Interface and Band Combinations Questions…. Definitions. - PowerPoint PPT PresentationTRANSCRIPT
Introduction to Remote SensingIntroduction to Remote Sensing Example Applications and Principles
Exploring Images with MultiSpecExploring Images with MultiSpec User Interface and Band Combinations
Questions…Questions…
DefinitionsDefinitions
Lillesand and Kiefer (1994)Lillesand and Kiefer (1994) – ““The science and art The science and art of obtaining information …acquired by a of obtaining information …acquired by a device that is not in contact with the device that is not in contact with the object…object…””
CCRS GlossaryCCRS Glossary – “A group of techniques for A group of techniques for collecting image or other forms of datacollecting image or other forms of data … … from measurements made at a distance from measurements made at a distance from the object, from the object, and the processing and and the processing and analysis of the dataanalysis of the data.”.”
Examples of Remotely Sensed DataExamples of Remotely Sensed Data
Weather Ocean Properties Physical Geography Major Disturbance Events / Hazards Cultural Features – urban mapping Many other examples – thematic info
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disturbance
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From Lillesand and Kiefer (1994)
Decision
Decision
From Lillesand and Kiefer (1994)
From Lillesand Kiefer (1994)
An Electromagnetic Wave
ll = wavelength = wavelength
nn = frequency = frequencyc = velocity of lightc = velocity of light
OO33 absorption absorption at 0.2 at 0.2 uumm
HH22O absorption O absorption at 1.4, 1.6, and 1.9 at 1.4, 1.6, and 1.9 uumm
COCO22 absorption absorption at 2.0 at 2.0 uumm
CHCH44 absorption absorption at 2.2 – 2.5 at 2.2 – 2.5 uumm
Human eyeHuman eye
Incident EnergyIncident Energy Reflected EnergyReflected Energy
E(E(ll))ii – [ E( – [ E(ll))aa + E( + E(ll))t t ] = E] = Err((l)l)
Rayleigh ScatteringRayleigh Scattering
Rayleigh Scattering as a Function of Wavelength
0
5
10
15
20
25
30
35
40
45
0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8
Micrometers (um)
Rel
ativ
e In
ten
sity
of
Sca
tter
ing
Atmospheric InteractionsAtmospheric Interactions
Types of Satellite OrbitsTypes of Satellite Orbits
Geostationary – 35,790 km above the EarthGeostationary – 35,790 km above the Earth
Sun-synchronous or “Polar”– between 700 and 800 Sun-synchronous or “Polar”– between 700 and 800 km above the Earthkm above the Earth
Satellite Orbits
http://science.nasa.gov/Realtime/jtrack/3d/JTrack3D.htmlhttp://science.nasa.gov/Realtime/jtrack/3d/JTrack3D.html
““Resolution” in Remote SensingResolution” in Remote Sensing
Four typesFour types
1)1) SpatialSpatial –the ground coverage / pixel –the ground coverage / pixel
2) 2) SpectralSpectral – area and subdivision of the EM spectrum – area and subdivision of the EM spectrum
3) 3) TemporalTemporal – frequency of coverage – frequency of coverage
4)4) RadiometricRadiometric – sensitivity to changes in energy intensity – sensitivity to changes in energy intensity
Issues of spatial & temporal scale Issues of spatial & temporal scale of the sensor platformof the sensor platform
--SPATIAL-SPATIAL-
““grain” and “extent”grain” and “extent”
‘‘Pixel’Pixel’
-TEMPORAL--TEMPORAL-
Frequency of imagingFrequency of imaging
September 15September 15 September 30September 30
October 15October 15 October 30October 30
Color Theory and Band CombinationsColor Theory and Band Combinations
AdditiveAdditive colors vs. colors vs. SubtractiveSubtractive colors colors
‘‘Natural’ and ‘False’ color compositesNatural’ and ‘False’ color composites
Displaying images, extracting informationDisplaying images, extracting information
Additive PrimariesAdditive Primaries
Subtractive PrimariesSubtractive Primaries
No single primary can be formed by No single primary can be formed by mixture of other twomixture of other two
All other colors can be formed by All other colors can be formed by mixtures of additivesmixtures of additives
Representations of color via Representations of color via pigments and dyespigments and dyes
Yellow absorbs blue, cyan absorbs Yellow absorbs blue, cyan absorbs red, magenta absorbs greenred, magenta absorbs green
Blue (0.45 um) Green (0.55 um) Red (0.65 um)
Blue (0.45 um) Green (0.55 um) Red (0.65 um)
Green = 2.5 x
Red = x Blue = x
Feb. 14, 2006 MODIS Terra, Eastern US
Snow Vs. Clouds
Clouds scatterat all wavelengths
Snow absorbs at >1.4 m
Snow Vs. Clouds
Clouds scatterat all wavelengths
Snow absorbs at >1.4 m
c
Natural Color Natural Color 33,,22,1,1
Color IR Color IR 44,,33,2,2
False Color False Color 55,,44,3,3
MultiSpec RS SoftwareMultiSpec RS Software
Research and educationResearch and education Long period development and refinementLong period development and refinement Freely availableFreely available Supported by tutorialsSupported by tutorials
http://cobweb.ecn.purdue.edu/~biehl/MultiSpec/http://cobweb.ecn.purdue.edu/~biehl/MultiSpec/