Post on 26-Dec-2015
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Geology 5631
David E. Pitts
January 23, 2012Copyright 2012
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
General Skills
-Conversion of Temperature
Method to convert temperature deg C to deg For deg F to deg C
1) Add 40
2) for deg C to deg F multiply by 9/5
for deg F to deg C multiply by 5/9
3) Subtract 40
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
General Skills
-Conversion of Temperature
Method to convert temperature deg C to deg For deg F to deg C
1) Add 40
2) for deg C to deg F multiply by 9/5
for deg F to deg C multiply by 5/9
3) Subtract 40
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
• Example 2
• The Curie point is that temperature above which magnetism is lost = 580 deg C. Earth's surface is about 30 deg C.
• If the temperature inside the Earth increases by 30 deg C each km of depth, at what depth does magnetism of the Earth's rocks disappear.
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
General Skills
Julian Days are the number of days since 12 noonJanuary 1, 4713 B. C.
for example August 23, 2011 is Julian Day 2,455,796It is also day of year (DOY) 235
The date January 1, 4713 B. C. is day zero in the Revised Julian Calendar Named for Julius Scaliger in 1582 by his son. Convenience for astronomers (no leap years, leap centuries).
Julian Calendar (named after Julius Caesar) started in 45 B.C. It got the calendar back in sequence with the seasons. It had leap years, however it too, became out of sync with the seasonsReplaced with the Gregorian calendar in 1582.
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
•Remote sensing involves acquiring information about an object without touching it.
•The literal interpretation includes images from:Electron microscopesMRI (magnetic resonance imaging)CAT (computerized Axial Tomagraphy)PET (Positron Emision Tomography)Images taken by
movie film camerasvideo camerasstill film and digital cameras
Images taken fromaircraft
Earth orbital satellitesPlanetary spacecraftAstronomical spacecraft (e.g. Hubble)
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
• Passive Remote Sensing
– Instruments that depend solely on energy emitted or reflected from the scene
• e.g. cameras, infrared scanners & microwave scanners
• Active Remote Sensing
– Instruments that send a pulse of energy which is reflected from the scene
• e.g. flash camera, Lidar (Laser), Radar, Altimeters
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
• History of Remote Sensing
– 1839 Daguerreotype
– WW I Aerial Photography
– 1930’s Radar Development
– WW II near IR photography
– 1960 TIROS weather satellite
– 1965 NASA aircraft program
– 1969 Apollo 9 (feasibility of Landsat - 1)
– July 23, 1973 ERTS (Landsat -1)
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
NASA Earth Resources Division (Manned Spacecraft Center-Houston TX)
Began in November 1964 - Convair-240A (Leo Childs)Lockheed P-3A - 1967 (from Navy)RB-57F - July 1969 (USAF)Lockheed Hercules C-130B - Sept 1969
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
• Earth Observations Aircraft Program
• Some of the key personnel
– Leo Childs
– Olav Smistad
– Joe Algranti
– Al Watkins
Year Budget Personnel Missions
– 1965 $200K 22 11
– 1966 $840K 40 42
– 1967 $2.7M 83 57
– 1968 $5.97M 153 77
– 1969 $8.8M 179 80
– 1970 $10.9M 236 190
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Visible - Near Infrared Remote Sensing
Advantages
Detects chemical composition of targets
Less sensitive to physical structure of target than radar
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Visible - Near Infrared Remote Sensing
Atmospheric Transmission 0.4 - 2.5 m
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Visible - Near Infrared Remote Sensing
Green leaf reflectance - Palisade layerNear IR leaf reflectance - spongy leaf tissue
Leaf of Plant
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Visible - near Infrared Remote Sensing
Near Infrared (0.8 - 1.1 m) has higher leaf transmittance
G
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Lee et. al. (1997)
Green
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Thermal Infrared Remote Sensing
Advantages
Detects temperature of targets
Detects chemical composition of targets
Less sensitive to physical structure of target than radar
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Emissive Spectrum Atmospheric Transmission 4.0 - 14.0 m
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Radar Remote Sensing
Three principal advantages
Independent of sun illumination
Most clouds are transparent
Detects size, shape, and electrical properties of target
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Radar Remote Sensing
Band Wavelength__________________________________________
VHF 1 - 5 mP-Band 77-107 cmL-Band 15-30 cmS-Band 7.5-15 cmC-Band 3.75-7.5 cmX-Band 2.40-3.75 cmKu-Band 1.67-2.40 cmK-Band 1.18-1.67 cmKa-Band 0.75-1.18 cm
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Radar Remote Sensing
Penetration is a function of the amount of biomass in a canopy
Longer wavelengths will penetrate more and “see” more soil.
Radar 1 cm Wavelength Radar 1 m Wavelength
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Radar Remote Sensing
Shorter wavelengths are affected by smaller canopy components(e.g. K, X, and C bands)
- leaves and twigs
Longer wavelengths are affected by larger canopy components(e.g. L, P, and VHF bands)
- bole- stems- ground surface
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Radar Remote Sensing - Effect of the Atmosphere
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Radar Remote Sensing
Target Brightness
Size relative to radar wavelength
Shape relative to radar wavelength
Proportional to Dielectric Constant(increases with water content)
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Radar Remote Sensing
Noise in SAR images (speckle) should be removed
- median filter- adaptive filter
Texture in image
Analyzed using Haralik co-occurrence matricesto create additional bands(e.g. Verhoeye and De Rover (1996)
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Radar Remote Sensing
Research has shown that multiple wavelength, multiple polarization SARS are needed for:
Optimal Vegetation MappingSoil Moisture EstimationBiomass Estimation
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Hyperspectral Remote Sensing
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Hyperspectral Remote Sensing
Utilizes hundred of bands - provides spectroscopyfor each pixel in image
Reflective spectroscopy of surfaces
broad spectral signatures - nonunique
Not like sharp spectra of gases
Mixed pixels confound problem
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Hyperspectral Remote Sensing
Analysis Technique
Dark object subtraction (e.g. turbid free lakes)
Band ratios
Resulting signatures can be compared with:
field spectra
laboratory spectra
spectral data banks
David E. Pitts
Remote Sensing Principles & HistoryRemote Sensing Principles & History
Hyperspectral Remote Sensing
HICO/Raids on the International Space Station is the onlycurrently operating Hyperspectral Space instrument.
Terra (NASA) - MODIS 36 bands launch Dec. 18, 1999
Obview-4 (Warfighter) orbital Science Corp - launch failed
Hyperion - Launched Nov 2000 operated 1 yearUSGS provisions these images
•EnMap - pushbroom hyperspectral scanner (ESA)–30 m resolution–0.42 to 2.4 m (184 bands)–Launch 2013–Sun synchronous polar orbit