Heinz Ruther UCT

A brief Introduction

to

Remote Sensing

Heinz Ruther UCT

History of Commercial EarthHistory of Commercial EarthObservation SatellitesObservation Satellites

• 1959 - Explorer-6 - Transmission of First image of Earth from Space

• 1960’s - USA & USSR - numerous remote sensing missions for: weather,

intelligence and lunar landing programs

• Jul 72 - ERTS-1 (later named Landsat-1) - First civil remote sensing

satellite for Earth resources

• Feb 86 - SPOT-1 - Launch of French government developed, first

commercially operated RS satellite

• Oct 92 - US Land Remote Sensing Policy Act signed into law

licensing US companies to operate satellites for commercial use

Heinz Ruther UCT

Ikonos

Ground footprint

eg 4 by 4 m

Satellite

v

vMixcel : one value for eachband only

Band a Blue

Band b Green

Band c Red

Band d Infrared 1

Band e Infrared 2

Band f Thermal Infrared

Band g ………..

Pixel (resolution)

Heinz Ruther UCT Red Band

Heinz Ruther UCT Blue Band

Heinz Ruther UCT

Thermal Infrared Band

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Colour Composit

(blue/red/thermal)

Heinz Ruther UCT

Imaging Satellites Use Classificationby Spatial Resolution

• Very Low > 300 m Meteorology

• Low > 30 < 300 m Resources

• Medium > 3 < 30 m Land Cover-Use

• High > 0.5 < 3 m Features

• Very High < 0.5 m Details

Heinz Ruther UCT

Widely used Satellite Images

• Landsat (15 m, 30 m, 80 m)

• Spot ( 2.5 m and 4 m)

• Ikonos ( 1 m and 4 m)

• Quickbird ( 0.6 m and 2.4 m)

Heinz Ruther UCTGreen Band of Landsat Image 30 m Resolution

Heinz Ruther UCTInfrared Band of Landsat Image 30 m Resolution

Heinz Ruther UCT

Heinz Ruther UCT

Heinz Ruther UCT

0.78 - 0.89 µm20 mB3 : near infrared

0.61 - 0.68 µm20 mB2 : redSPOT 3

0.50 - 0.59 µm20 mB1 : greenSPOT 2

0.50 - 0.73 µm10 mPanchromaticSPOT 1

1.58 - 1.75 µm20 mB4 : mid infrared (MIR)

0.78 - 0.89 µm20 mB3 : near infrared

0.61 - 0.68 µm20 mB2 : red

0.50 - 0.59 µm20 mB1 : green

0.61 - 0.68 µm10 mMonospectral

SPOT 4

1.58 - 1.75 µm20 mB4 : mid infrared (MIR)

0.78 - 0.89 µm10 mB3 : near infrared

0.61 - 0.68 µm10 mB2 : red

0.50 - 0.59 µm10 mB1 : green

0.48 - 0.71 µm2.5 m or 5 mPanchromatic

SPOT 5

spectral bandspixel sizeelectromagnetic spectrumsensor

SPOT Image

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SPOT IMAGE

8 by 8 km section out of 60 km by 60 kmpanchromatic scene - 10 metre resolution

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1625 lines/sLine rate

3,454Number of cross-trackpixels

48 µm x 48 µmPixel size

Multispectral

6500 lines/sLine rate

13,816Number of cross-trackpixels

Panchromatic

12.2 kmSwath width

0.88 m PAN, 3.52 m MS,orbital altitude of 600 km

Spatial resolution (GSD)

0.45-0.52 µm, 0.52-0.60 µm,0.63-0.69 µm, 0.69-0.90 µm

Spectral range MS(multispectral)

0.45 - 0.90 µmSpectral range PAN(panchromatic)

High resolution IKONOS

Heinz Ruther UCT Ikonos 4 m Resolution Cape Town

Heinz Ruther UCT

Sidney Panchromatic Ikonos image 1 m resolution

Heinz Ruther UCTPan sharpened Ikonos Image Millennium Dome London 1 + 4 m

Heinz Ruther UCT

Heinz Ruther UCT

QuickBird

Highest resolution sensors available commercially

60-cm panchromatic at nadir

2.4-m multispectral at nadir

Heinz Ruther UCT

Quickbird 60 cm resolution image of Cancun, Mexico

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Quickbird 60 cm resolution image of Cancun, Mexico

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STEREO for DTM Generation

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• Classification

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Red Reflectance

GreenReflectance

Surfacecover type 1

Classification

Blue Green Red IRed

Surfacecover type 2

Signature

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Band 1

Band 2

Band 3

Heinz Ruther UCT

Heinz Ruther UCT

Applications in heritage

• Crop mark detection

• Landuse / landcover

• GIS (mapping)

• Landscape models

• Virtual historical landscapes

Heinz Ruther UCT

Heinz Ruther UCT

Heinz Ruther UCT

Airborne Laser Scanning

Penetrates Foliage

Generates Terrain (DTM) and Surfacemodel (DSM)

and intensity (texture and different materialsbut no colour)

Heinz Ruther UCT

SAR

Synthetic Aperture Radar

Penetrates Foliage and to some extentground (???)

Heinz Ruther UCT

Google Earth

Satellite images of the entireglobe in a wide range of

resolutions