Remote Sensing Readings 27 20 and lecture notes

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Remote Sensing

Remote Sensing

 • Readings: 27 -20 and lecture notes • Figures to Examine: 27 -20

• Readings: 27 -20 and lecture notes • Figures to Examine: 27 -20 to 27 -23. • Examine the Image from IKONOS, 27 -23 and compare it with the others.

Introduction • Definition: Remote Sensing is the science of obtaining information about an area,

Introduction • Definition: Remote Sensing is the science of obtaining information about an area, object, or phenomenon through the analysis of data acquired by a device which is not in contact with the object, area, or phenomenon under investigation. • Energy, mainly from the sun, propagates through the atmosphere, reflected or reemitted from the objects, and recorded by “sensors”.

The Electromagnetic Spectrum • Visible wave lengths are very limited , 0. 4 to

The Electromagnetic Spectrum • Visible wave lengths are very limited , 0. 4 to 0. 7 mm, Near IR 0. 7 to 1. 3 mm, mid IR 1. 3 to 3 mm. They both could be recorded on films. • Thermal IR is mainly emitted from an object, needs thermal scanning. • Microwaves are very long waves 1 mm to 1 m • Most common sensing systems operate in one or several of the visible, IR, or microwave portions of the spectrum. • Energy emitted by the sun is within the visible portion, earth’s emitted energy is within thermal IR portion.

Spectral Reflectance • The ratio between the reflected energy and the incident energy at

Spectral Reflectance • The ratio between the reflected energy and the incident energy at a certain wave length. • A certain object will have different spectral reflectance at different wave lengths • Different objects will have different spectral Reflectance at the same wave length • Examples: Deciduous and coniferous trees, vegetation, soil and water. • Why do we see “green”. • What is spectral signature?

Reflectance % Dry soil gray brown Vegetation green Water clear Wavelength µm

Reflectance % Dry soil gray brown Vegetation green Water clear Wavelength µm

Normal Color photo Infrared color photo Notice the difference in color between natural vegetation

Normal Color photo Infrared color photo Notice the difference in color between natural vegetation and artificial turf

Deciduous (needle) and coiffeurs trees (broad leaves) reflect the same Deciduous (needle) trees reflect

Deciduous (needle) and coiffeurs trees (broad leaves) reflect the same Deciduous (needle) trees reflect more, brighter Normal B/W photo 0. 4 to 0. 7 µm B/W Infrared photo 0. 7 to 0. 9 µm

Thermal and Multispectral scanners • Thermal scanners will detect the emitted energy in thermal

Thermal and Multispectral scanners • Thermal scanners will detect the emitted energy in thermal IR band. • Multispectral scanners will detect the reflected energy in the visible, IR and microwave bands, includes a number of detectors corresponding to the number of bands detected. • Thermal IR multispectral scanners. • Imaging Spectrometry: acquisition in many, very narrow, contiguous spectral bands from visible to mid IR

Earth Resource Satellites • There are several types of satellites above you: communications, remote

Earth Resource Satellites • There are several types of satellites above you: communications, remote sensing, GPS, radio and TV, . . • US “Lnad. Sat”: – Ground coverage 185 km x 185 km. Equals to 1600 photos at 1: 20, 000 with no overlap. – Sensors: MSS, TM, best resolution: 30 m in black and white, Land. Sat 7: 15 m • French “Spot”: – Ground coverage is 60 x 60 km – Sensors: High Resolution Visible (HRV). Operates within a limited band width: 0. 51 to 0. 89. Resolution of 10 m in B/W, spot 5: 2. 5 m

 • Spot has a better spatial resolution and less spectral resolution than Land.

• Spot has a better spatial resolution and less spectral resolution than Land. Sat • Spot imaging system could be oriented to survey a certain area at a certain time and to produce stereo pairs. • Other available systems, some with higher accuracy Such as IKONOS, figure 27 -23, 1 m resolution, and Spin-2 2 m resolution. • Quick Bird: Resolution up to 60 cm is commercially available today.

Spot twin system

Spot twin system

SPOT 10 m resolution B/W Image LA, California

SPOT 10 m resolution B/W Image LA, California

DEM generated from Spot imagery

DEM generated from Spot imagery

Quick Bird 60 cm Image of Buckingham Palace- England

Quick Bird 60 cm Image of Buckingham Palace- England

Quick Bird 60 cm image

Quick Bird 60 cm image

1 m Ikonos Image in Jamaica

1 m Ikonos Image in Jamaica

Washington D. C 5 M IRS Image

Washington D. C 5 M IRS Image

2 m resolution satellite image of Giza-Egypt, courtesy of Spin-2

2 m resolution satellite image of Giza-Egypt, courtesy of Spin-2

60 cm image of a runway in Egypt

60 cm image of a runway in Egypt

Daytime thermal image Quantico, VA

Daytime thermal image Quantico, VA

In this image blue indicates the snow cover, orange and yellow colors are characterizing

In this image blue indicates the snow cover, orange and yellow colors are characterizing the rock type and lava age, and the red color is indicating heat. (Image courtesy of NASA/Ames Research Center)

courtesy of SE-IR Corporation, Goleta, CA)

courtesy of SE-IR Corporation, Goleta, CA)

Infrared photograph of Niagara Falls taken from NASA Earth Survey 2 aircraft

Infrared photograph of Niagara Falls taken from NASA Earth Survey 2 aircraft

infra red picture of St Gimignano

infra red picture of St Gimignano

Nighttime thermal IMAGE HEAT LOSS

Nighttime thermal IMAGE HEAT LOSS

Site of the ancient city of Spina, Italy

Site of the ancient city of Spina, Italy

Recently plowed fields that reveals the foundation of a 320 -m long Roman village

Recently plowed fields that reveals the foundation of a 320 -m long Roman village in northern France.

Digital Image Processing • What is a digital Image • Basic Operations: – Image

Digital Image Processing • What is a digital Image • Basic Operations: – Image rectification and restoration – Image enhancement – Image classification – Data merging