David E. Pitts Remote Sensing Principles & History Geology 5631 David E. Pitts January 23, 2012 Copyright 2012

David E. Pitts

Remote Sensing Principles & HistoryRemote Sensing Principles & History

Geology 5631

David E. Pitts

January 23, 2012Copyright 2012

David E. Pitts


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


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


David E. Pitts


• 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


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 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


• 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


• 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


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


• 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


Visible - Near Infrared Remote Sensing

Advantages

Detects chemical composition of targets

Less sensitive to physical structure of target than radar

David E. Pitts



Atmospheric Transmission 0.4 - 2.5 m

David E. Pitts



Green leaf reflectance - Palisade layerNear IR leaf reflectance - spongy leaf tissue

Leaf of Plant

David E. Pitts


Visible - near Infrared Remote Sensing

Near Infrared (0.8 - 1.1 m) has higher leaf transmittance

G

David E. Pitts


Lee et. al. (1997)

Green

David E. Pitts


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


Emissive Spectrum Atmospheric Transmission 4.0 - 14.0 m

David E. Pitts


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



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



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



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


Radar Remote Sensing - Effect of the Atmosphere

David E. Pitts



Target Brightness

Size relative to radar wavelength

Shape relative to radar wavelength

Proportional to Dielectric Constant(increases with water content)

David E. Pitts



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



Research has shown that multiple wavelength, multiple polarization SARS are needed for:

Optimal Vegetation MappingSoil Moisture EstimationBiomass Estimation

David E. Pitts


Hyperspectral Remote Sensing

David E. Pitts



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



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



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

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David E. Pitts Remote Sensing Principles & History Geology 5631 David E. Pitts January 23, 2012 Copyright 2012