geom3003 engineering surveying (mining)

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GEOM3003 Engineering Surveying (Mining)

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The previous Slide Set contains:

Spatial InformationTerrain Modelling

GIS, Geographic Information Systems

This Lecture Notes Slide Set contains:In t roduc t ion to Remo te Sensing

The next Silde Set contains:

Introduction to Photogrametry

Dr Gerd R Dowideit

School of Geography, Planning and Architecture

The University of Queensland

Copyright, 2004
http://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_6.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_6.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_6.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_5.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_7.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_8.pptmailto:[email protected]://www.gpa.uq.edu.au/http://my.uq.edu.au/http://my.uq.edu.au/http://www.gpa.uq.edu.au/mailto:[email protected]://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_8.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_7.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_5.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_6.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_6.ppthttp://localhost/var/www/apps/conversion/tmp/scratch_5/Lect_6.ppthttp://c/Linked%20Notes/links.html


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Start this PowerPoint Session as a Slide Show !

Engineering Surveying (Mining)THE UNIVERSITYOF QUEENSLAND

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Remote SensingLecture 7, Part 1

Dr Gerd R Dowideit


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Remote Sensing

An Introduction:

What is REMOTE SENSING ?

REMOTE SENSING inclu des al l m ethods

and techniq ues used to g ain qual i tat ive and

quant i tat ive inform ation abou t distant

objects wi thout com ing into di rect contact

with these objects.

Loo k-Look , NO Touch

Landsat TM

Near IR Band
http://c/Linked%20Notes/links.html


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Remote Sensin g (RS) metho ds try to answerfour basic quest ions:

HOW MUCH of WHAT is WHERE?

What is the SHAPE and EXTENT of ... ?

(Area, Bo undaries, Lineaments, ...)

Has it CHANGED?

What is the MIX of Objects

Remote Sensing

An Introduction:



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HOW MUCH of WHAT is WHERE?

WHAT: Type, Characteris t ic and Propert iesof Object . eg. Water, Vegetation, Land;

Temperature, Concent rat ion , State of

Developm ent; Subty pe, Species,

Use of ... ; Inclu des determinat ion of

gener ic ob ject type, character and prop erty

as well as its abstract meaning.=> DATA INTERPRETATION

Remote Sensing

An Introduction:



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HOW MUCH of WHAT is WHERE?HOW MUCH: determ ine by simple

COUNTING, measur in g AREA cov ered or

percentage of total area cov erage.

WHERE: Relate location s and area

co vered to either a standard map or to the

actual location on the ground where the

object occu rs.NOTE: WHERE also refers to a moment in

t ime

Remote Sensing

An Introduction:



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What is the SHAPE and EXTENT of ...

? (Area, Bo und ar ies, Lineaments)This extends the WHERE to be a completely

GEOMETRIC p rob lem. MAP PRODUCTION

methods are to be appl ied to the analysis o f

RS informat ion. These include:

Photogrammetric Methods:

Identification and Delineation of Boundariesand Lineaments (Roads, Rivers, Fault Lines)

Remote Sensing

An Introduction:



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Has it CHANGED?

CHANGE may occu r wi th progress of

TIME.

Change may be detected throug h

com parison o f observed states at dif ferent

moments in time.

=> CHANGE DETECTION

Remote Sensing

An Introduction:



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What is the MIX of Objects?

The surface of the Earth is c overed byob jects like So il, Water, Grass , Trees,

Houses, Roads and so o n. These are

GENERIC OBJECTS. We know these

wel l , but w e also kn ow objects l ike

Open Forest, Residential and Industrial

Estates, etc. Each of theseABSTRACTOBJECTS are made up of a typical

col lect ion o f Gener ic Objects.

Remote Sensing

An Introduction:



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Remote Sensing (Look-Look, NoTouch) is a much wider field than

we will discuss in this lecture

series. We will concentrate on that

part of RS dealing with

EARTH RESOURCES

Vision Medical Imaging

Sound and Radio Wave Detection

Remote Sensing

An Introduction:



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What makes i t t ick ?? ?

(1) RS requir es aCARRIERof

information, which can br idgedistances.

(2) RS requ ires a SENSOR whic h can

detectchanges in the carried Signal.

(3) RS requ iresRECORDING,

ANALYSIS, INTERPRETATION and

REPRESENTATION of the sensedinformat ion in a pu rposefu l way.

(1) RS requir es aCARRIERof information,

which can br idge dis tances.

These Carriers of Information are FIELDS of

FORCES:

* Pressure Wave Fields of Sound,

* Gravity Force Fields,

* Magnetic Force Fields and

* Electro-magnetic Force Fields.

The lat ter are of our main interest, sincethey inc lude vis ib le and invis ib le LIGHT.

Remote Sensing

An Introduction:



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(2) RS requir es a SENSOR wh ich c an detect

changes in the carried Signal.

Apart f rom o ur ow n eyes and ears,techno logy has prov ided us wi th a mul t i tude

of sensors operat ing in the d etect ion of

force f ields:

microph ones, geophon es,

photo graphic f i lm, v ideo cameras and photo

detectors,radio w ave receivers, gravimeters and

magnetometers.









Remote Sensing

An Introduction:



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(3) RS requ iresRECORDING, ANALYSIS,

INTERPRETATION and REPRESENTATION

of the sensed inform ation in a pu rposefu lway.

This is a techniq ue based top ic. It is

essent ial for the su ccess o r fai lure of RS

in respect of its anticipated purpose.

This topic will be dealt with in its main

aspects (bu t not completely).









Remote Sensing

An Introduction:



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Source of ForceField

Reflection

Sensor System eg. Camera

Resulting RS DataSet

eg. Image

DATAACQUISITION

Remote Sensing

An Introduction: What is Remote Sensing


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RS Data Seteg. Image

DATAPROCESSING

Interpretation

(secondary) MeasurementsData Processing & Mapping (geometric)Presentation of Processing Results

Explaining deduced OBJECT INFORMATION

Remote Sensing

An Introduction: What is Remote Sensing

Model of Real World


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Remote Sensing

Electromagnetic Radiation:

Fraunhofer Lines

(found empirically byobservation)

Dispersion of Light

through a refractive

prism

Fraunhofer discovered black lines

in the spectrum of light emitted by

various superheated chemical

elements. These lines were as

typical for each of the elements asfingerprints for humans.

Chemica l Composi t ion of

ob jects effects em itted ER in

a unique way for eachelement.


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Fraunhofer Lines

Dispersion of Light

through a refractive

prism

E = mc2

In Einstein's formula

E = mc^2

E = Energy

m = mass (of matter/object)

c = propagation velocity of

light

What does that tel l us ?

There is a well defined relationship

between MATTER, ENERGY and

ELECTROMAGNETIC RADIATION

(eg. light)

Remote Sensing



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The basic building blocks of all matter are ATOMS

The basic building blocks of Atoms are the

NUCLEUS (Neutrons and Protons) and several

ELECTRONS.

Electrons are thought to be spinning around the

Nucleus at orbits of different, but well pre-defined

discrete sequential radii.

A change in the energy level contained in an atom

(eg. by heating or cooling) changes

the balance of forces inside the atom willautomatically adept to energy level changes by

moving electrons to higher or lower orbits.

Remote Sensing



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The loss of energy from an atom causes

electrons to drop back to lower orbits

which is of interest to us.

One widely accepted theory says, that

atoms lose energy in form of

Electromagnet ic Radiat ion

One theo ry exp lains ER as a WAVE field,

another as a f ield o f a stream of

PHOTONS, partic les so small that they

have no mass.Bo th are said to p ropagate at l ight s peed.

Photon

Wave

Energy differential = 1 Plancks Quantum E = mc^2

Remote Sensing



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Photon

Wave


Some atom s may have been charged to a high e

energy level ; pu shin g electron s further than one

orb i tal level . In turn they can dr op b ack over

mo re than one orbi t level : mo re energy than

one Quantum

Gerds interpretation:

Since c is cons tant, al l pho tons travel about

300,000 km /sec

Those with a high er energy ch arge wi l l use a

more wiggly (thus, longer) wave path than

thos e with lesser charge.

Remote Sensing



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Photon

Wave


Wave characteristics:

= Wave leng th = distance between cons ecut ivewave peaks (measured inm)f = frequenc y = num ber of wave peaks (wiggles) in

the wave train p ropagat ing fo r 1 sec (measured in

Hz)

= c / fSumming up:

High Energy Radiat ion proc eeds at high er

frequencies (sho rter wavelength compares to low

energy radiat ion.

Radiation wave length m ix depends on amount of(heat) energy con tain in matter.

=>PLANCKs LAWc = const ~ 300000km/sec

Remote Sensing



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PLANCKs LAW

Wave Length

Total Radiation

Energy emittedRadiation Energy Curve for

an object (BLACK BODY)

at constant temperature.

short long

peak

WIENs LAW

Wave Length

Total Radiation

Energy emitted

Radiation Energy Curves foran object (BLACK BODY) at

various constant temperatures.

short long

300K

1000K

3000k6000K

Radiation output curves for ideal (Black Body) objects

Remote Sensing



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The Average Temperature of Earths

Surface rarely exceeds 300 K, an object

temperature to low to provide for

EMITTED RADIATION of sufficient

strength to register on most of the

available sensors (except in thermal IRsensors).

(Even warm nights can be pitch black)

WIENs LAW

Wave Length

Total Radiation

Energy emittedRadiation Energy Curves for

an object (BLACK BODY) at

vari ous constant temperatures.

short long

300K1000K

3000k6000K

The surface of the Suns outer atmosphere

(photosphere) has a temperature of about

5800K, hot enough to provide adequate

radiation energy. (Peak output in GREEN

of visible light).

Most RS systems ut i l ise ref lected su n l ight.

Remote Sensing



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QUESTION: Does incident

sun light interact in a

similar way with matter as

described is the case for

emitted radiation?ANSWER: YES!

ER (includ ing l igh t) is a

form of energy (as is heat).

Matter (atoms) can absorb

as wel l as emit energy.

Objects under illumination by sun light

will partially absorb radiation.

Absorption level varies with wave

length depending on chemicalcomposition of the object

Radiation not absorbed is mostly

reflected and available for RS.

=> Spectr al Sign atures

Remote Sensing



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GN238 Introduction to Remote Sensing 01/10/97 5

ER, the Physical Basis of RSExamples of Spectral Signatures

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0.4 (blue) 0.80.6 (red)0.5 (green) 0.7 (IR=>) 1.0m

%Reflectance

(of Sun Light)

0

Bare Soil (Grey/Brown)

Vegetation (green)

Water (clear)

(


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GN238 Introduction to Remote Sensing 01/10/97 6

ER, the Physical Basis of RSThe Electromagnetic Spectrum

(not to exact scale; see Textbook)

10^ -6 10^ -3 1 100 0.1 10^5 10^ 8

-Rays

Sound

X-Ray UV

Visible

0.4 0.5 0.6 0.7m

m

TV/RadioM icro-

Wave

Thermal Inf rared

Near & M id I nfrared

Wave L ength

not part of ER)

Note: outsidethe visible Range,

no colours or

shades will be

perceived.Blue Green Red

Remote Sensing


GEOM3003 E i i S i (Mi i )


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The General Remote Sensing Model

I

R

AT

A

Sensor

Radiation

Source

I = R + A + T

Simplified

Radiation-

Balance

R = I - A - T

I = Incident ERR = Reflected

A = Absorbed

T = Transmitted

S = Scattering

S

Remote Sensing


GEOM3003 E i i S i (Mi i )


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ER, the Physical Basis of RSA bright I dea for RS

50

0.4 (blue) 0.80.6 (red)0.5 (green) 0.7 (IR=>) 1.0m

%Reflectance

(of Sun Light)

0

Bare Soil (Grey/Brown)

Vegetation (green)

(


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A brig ht Idea for RS

G R IR

Truth Table

Veg. Soil

G med med

R low high

IR high+ high

Remote Sensing


GEOM3003 Engineering S r e ing (Mining)


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Image

Display

Remote Sensing




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Ekati Diamond Mine,

Northwest Territories

1989 1994 1999Colour coded

CompsiteChange Detection:Impact of Mine Development on

the Environment

Remote Sensing




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Spectral Classification of a Landsat MSS scene

Remote Sensing




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Using Fraunhofers ObservationsThe variation in Radiation output from a REAL OBJECT depends on its

chemical composition. Water has a different SPECTRAL SIGNATURE than

soil or chlorophyll containing leaf matter, etc.

Wave Length

Radiation Energy Curve for

an object at constant temperature.

short long

Gerds real

object

QUESTIONS:

Can we use these facts to

measure object

temperatures?

Can we use these facts to

identify the chemicalcomposition of objects and

can we use the latter to

identify the object itself?

Remote Sensing


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