fe-i 7_tir basics+appl

Remote Sensing Section

Remote Sensing - I

- Thermal Infrared -Basics and Application


Blackbody Radiation, Atmospheric Transmission and Regions of Operation for Remote Sensors

UV

Blu

eG

reen

Red

IR

Sun’s radiant energyat 5800 K

Earth’s radiant energy at 288 K

K b

and

X b

and

C b

and

P b

and

Radar Instruments

Passive microwave

Human eyePhotography Thermal scanners

Ener

gy

Optical scanners - ms/xs

Tran

smis

sion

%

100

adapted from Lillesand & Kiefer (1994)

Wavelength in Microns

0.2 0.3 0.6 1.0 2.0 4.0 6.0 10 20 40 60 100 200 0.5 mm 1 cm 1 m 10 m 100 m

0.2 0.3 0.6 1.0 2.0 4.0 6.0 10 20 40 60 100 200 0.5 mm 1 cm 1 m 10 m 100 m

0 VIS NIR SWIR MIR TIR


Fundamentals (Reststrahlen) of TIR (Silica)

a)

c)

b)a cb

a) 8 – 10 µm: asymmetricSi – O – Si stretching vibrations

b) 12 – 14 µm: symmetric Si – O – Si stretching vibrations

c) 17 – 25 µm: O – Si – O bending vibrations


Spectral Features in the TIR Range

1 Forsterite Nesosilicate (Insel)2 Olivine #3 Pyroxene Inosilicate (Ketten)4 Hornblende #5 Labradorite Tectosilicate (Gerüst) 6 Oligoklase #7 Albite #8 Orthoklase #9 Quartz #9

8

7

65

4

3

2

1


Feldspars and Carbonates

VNIR/SWIR Reflectance

TIR EmittanceOrthoclase

Albite

Calcite

SWIR

Albite

Orthoclase

TIR

Calcite


TIR – Laboratory Measurements at Thin Sections


EO-Sensors providing Thermal Data

TIMS (airborne) ASTER Landsat (E)TM/OLI NOAA AVHRR

4.0 m x 4.0 m GSD 90 m x 90 m GSD 120 m x 120 m GSD 1.1 km x 1.1 km GSDat 1.5 km flight alt. TM 1-6

60 m x 60 m GSD ETM 7 100 m x 100 m GSD

Spectral Bands (in microns)

# 1: 8.2 - 8.6 # 10: 8.125 - 8.475 # 6: 10.4 -12.5 # 3: 3.55 - 3.93# 2: 8.6 - 9.0 # 11: 8.475 - 8.825 # 10: 10.3 -11.3 # 4: 10.5 - 11.5# 3: 9.0 - 9.4 # 12: 8.925 - 9.275 # 11: 11.5 -12.5 # 5: 11.5 - 12.5# 4: 9.4 - 10.2 # 13: 10.25 - 10.95# 5: 10.2 - 11.2 # 14: 10.95 - 11.65# 6: 11.2 - 12.2

TIMS served as simulator for the space-borne ASTER-System (Advanced Spaceborne Thermal Emission and Reflection Radiometer)


Emissivity 'ɛ' and Temperature

Variations of 'ɛ' can be used to identify surface materials 'ɛ' and temperature are superimposed in thermal data sets

and thus are not directly deducible Methods for separation have to be applied Surface temperatures of homogenous objects like

waterbodies are relatively easily deducible as 'ɛ' is known and constant

At land surfaces, where 'ɛ' varies on small scale with changing geochemistry of materials (e.g. minerals or pigments), 'ɛ' is dominated and masked by temperature effects


Emissivity of Materials measured in the 8-12µm Region

Source: from Buettner, K.J.K., and C.D. Kern, Journal of Geophysical Research,v. 70, p. 1333, 1965, copyrighted by American Geophysical Union


System Correction of Data in the TIR-Range - I

Lsensor (λ) = Lscatter (λ) + τ (λ) ε (λ) Lbb (λ,T)+ τ (λ)(1- ε (λ))F(λ)

Lsensor = Total radiance at sensor (mW/m2sr µm) Lscatter = Scattered light (atmospheric emission and scattering (mW/m2sr µm)) τ = atmospheric transmission (ground surface - sensor) ε = Ground surface emissivity Lbb = emitted radiance of a blackbody (mW/m2sr µm) at a temperature T (K) F = thermal heat flow from atmosphere to the ground surface (mW/m2sr µm)

Recorded radiance is determined by the emitted blackbody radiation Lbb, the stray light Lscatter, the emissivity of the ground ε, the transmission τ and the downwelling heat flow F.


System Correction of Data in the TIR-Range - II

The integrated, emitted blackbody radiation Lbb (ε = 1) is described by the given surface temperature T by Planck's function in relation to the wavelenght for each band

Natural surfaces do not emit radiance like an ideal blackbody

The spectral emissivity ε is defined by

εi = Li ground surface / Li bb

as ratio of the (ground) materials radiation versus the radiation of a blackbody at the same temperature


Thermal Characteristics of Minerals (and Water at 20oC)

source: Janza and others (1975)

Thermal conductivity(K),

cal*cm -1sec -1*°C -1

Density g*cm -3

Thermal capacity(c),

cal*g -1*°C -1

Thermal diffusity(k),

cm 2*sec -1

Thermal inertia(P),

cal*cm -2*sec -1/2*°C -

1

1 Basalt 0.0050 2.8 0.20 0.009 0.0532 Clay soil, moist 0.0030 1.7 0.35 0.005 0.0423 Dolomite 0.0120 2.6 0.18 0.026 0.0754 Gabbro 0.0060 3.0 0.17 0.012 0.0555 Granite 0.0075 2.6 0.16 0.016 0.0526 Gravel 0.0030 2.0 0.18 0.008 0.0337 Limestone 0.0048 2.5 0.17 0.011 0.0458 Marble 0.0055 2.7 0.21 0.010 0.0569 Obsidian 0.0030 2.4 0.17 0.007 0.035

10 Peridotite 0.0110 3.2 0.20 0.017 0.08411 Pumice, loose, dry 0.0006 1.0 0.16 0.004 0.00912 Quarzite 0.0120 2.7 0.17 0.026 0.07413 Rhyolite 0.0055 2.5 0.16 0.014 0.04714 Sandy gravel 0.0060 2.1 0.20 0.014 0.05015 Sandy soil 0.0014 1.8 0.24 0.003 0.02416 Sandstone, quartz 0.0120 2.5 0.19 0.013 0.05417 Serpentine 0.0023 2.4 0.23 0.013 0.06318 Shale 0.0042 2.3 0.17 0.008 0.03419 Slate 0.0050 2.8 0.17 0.011 0.04920 Syenite 0.0077 2.2 0.23 0.009 0.04721 Tuff, welded 0.0028 1.8 0.20 0.008 0.03222 Water 0.0013 1.0 1.01 0.001 0.037


Relationship of Thermal Inertia to Density of Rocks

Ther

mal

iner

tia ,

cal *

cm

-2 *

sec

-1/2

* °

C-1

Density, g * cm-3

.0080

.0060

.0040

.0020

1 2 3

11

22

15

216 18

9

2

1420 13

16 81

4

17

123

10

5

Numbers refer to the materials listed in the previous table

modified from: Sabins (1987)


Surface Temperatures of Rocks with varying Inertia and Albedo

source: Watson (1971)

Materials with different ther-mal inertias

Materials with different albedos

0

20

40

60

800.01

0.03

0.05

0.01

0.05

Sur

face

tem

pera

ture

°C

0.05

0.01

0

20

40

60

Sur

face

tem

pera

ture

°C

0.10.3

0.5

Thermal Symbol Rock Inertia Albedo

Dolomite 0.023 0.19Limestone 0.036 0.22Granite 0.058 0.15

0

20

40

Sur

face

tem

pera

ture

°C

12noon

18 0midnight

6 12noon

Limestone, Dolomite, and Granite



The Effect of varying thermal Capacities of different Rock Types

Paraffin

Rhyolite0.40

Limestone0.42

Sandstone0.47

A. Spheres of rock heated to 100 °C and placedon a sheet of paraffin. The value for each rock isthe product of its thermal capacity (c) and densityin cal*cm-3*C-1.

B. After the rocks and paraffin have reached thesame temperature

source: F. Sabins (1987)


Variations in diurnal Surface Temperature

Sur

face

tem

pera

ture

Noon Midnight Noon Midnight

Materials with lower thermal inertia;shale, cinders, high T

Materials with higher thermal inertia;sandstone, basalt, low T

T T



Diagramatic diurnal Radiances of Objects

0 4 8 12 16 20 0 Hours

localdawn

Midnight Noon Midnight

Rad

iant

Tem

pera

ture

localsunset

Rock

s

(typical)

&soils

Vegetation

standing water

Damp terrain

Metallic objects



Heat Loss Survey of Brookhaven Nat. Laboratories

Long Island, New York

Arial Photografh with overlay of heating lines Nighttime thermal IR image (8 to 14 µm)



Stilfonteine Area, Western Transvaal, South Africa

Arial photograph

Interpretation map of thermal IR image

Mine tailings pond0 0.5 mi

0 0.5 km

Dolomite andcherty beds

Dolomite andcherty beds

Dolomite Dolomite


Nighttime thermal image (8 to 14 µm)


Thermal Survey Hengill/S-Island (Thematic Mapper)

Highest temperatures are indicated by saturated red colors

Coldest temperatures are indicated by green colors to non saturated white (snow covered Hengill)

IHS-Color Compositeof Thematic Mapper DataI=band 4; HS=band 6


Heat Capacity Mapping Mission (NASA-78)

Day TIRNight TIR

VIS

geol.Map

600m GSD/10.5-12.5µm


Visible Data versus Day/Night IR

Day-IRVisible Night-IR


Pelleponnesus – Gulf of Nauplia

TM-bands 7,4,1 coded RGB

TM-bands 4,3,1 coded RGB


Lithological Units derived from Landsat TM Data

Argos

Nauplia

Tripolis

Stimtalia

Holous

sa

Alea

37°50'

37°40'

37°30'

22°30' 22°40' 22°50'

Gulf of Argos

T r i p o l i s

Argos

Nauplia

Tripolis

Hol

ouss

a

Alea

Skot

ini

Legend

young soil deposits, slope debris, fullsediments of the poljes (Quaternary

moris, conglomerates (Neogene)

limestones (Olonos-Pindos nappe)

sandstones, siltstones (Tripolis nappe)

limestones (Tripolis nappe)

metamorphic sediments (Phyllit series)

polje

settlement

N

0 5 10 15 km

Geological Sketchmap of the Central and NE-Peloponnesus


Thermal Data – Fresh Water Discharge

124

124

123

119

121 122

119

DN Values (not converted to absolute temperature)each step is equivalent to ~0.6 °C

Kroe

Lerna

Kiveri

Band 4(blue part)Contamination from harbor

Fresh water invisibile

Dam constructionfor freshwater catchmentat Kiveri discharge

Anavalos

Kiveri


Tectonic Elements derived from Landsat TM Data

37°50'

37°40'

37°30'

22°30' 22°40' 22°50'

Argos

Anavolos

Kalalar

Tripolis

Nauplia

Stimtalia

Holous

sa

Alea

Structural Interpretation of the Central and NE-Peloponnesus

0 5 10 15 km

strike-slip fault

strike-slip fault

N

E

joint

joint

joint

S

W

polje

settlement

lineament

strike-slip fault

spring

sinkhole

tracer path ways


Tschernobyl - Facts

• the accident happened April 26, 1986 in Block 4 of the power plant near the city Prypjat in Ukraine

• within the first ten days after the explosion several trillion Becquerel have been released

• Isotopes Caesium-137 (RHL ~30 Jahre) and Iod-131 (RHL: 8 Tage) evaporated


Chernobyl - Thematic Mapper before nuclear accident: April 21, 1985

RGB: bands 7, 5 and 3.water color-coded by thermal band (6)

red -> yellow -> green -> blue warm -----------------------> cold

source: Richter et al. 1986


Chernobyl - Thematic Mapper 3 days after the nuclear accident: April 29, 1986

source: Richter et al. 1986

RGB: bands 7, 5 and 3.water color-coded by thermal band (6)

red -> yellow -> green -> blue warm -----------------------> cold


Basic Laws of Radiation IIBlackbody Radiation – Wien's Displacement Law

0.2 0.5 1 2 5 10 20 50 1000.110-6

10-5

10-4

10-3

10-2

0.1

1

10

102

103

104

UV VIS NIR MIR/TIR FIRR

elat

ive

Elec

trom

agne

tic In

tens

ity

Wavelength (Microns)

sun5800 K

molten lavanuclearaccident1400 K

forest fire

hot spring360 K

ambient

arctic ice220 K

288 K

1000 K

SWIR

Wien's displacement law

T rad

Kµm2897

max

adapted from Lillesand & Kiefer, 1994


Calculation of Kinetic Temperature from DN Values

165

TM-5 / 1.6 µm

36

33

26

31

44

25

33

29

36

44

23

66

44

44

26

73

47

47

39

42

46

34

60

40 42 37

35

59

69

64

72

TM-7 / 2.2 µm

21

19

16

18

26

17

6

14

23

27

8

91

20

27

23

13

149

85

24

27

25

21

43

45

41

38

21

20

32

45

43

43

93

Geometric Considerations:• calculate background/target radiation for selected pixels• calculate contributing fraction of target to selected pixels• calculate atmospheric attenuations• calculate spectral radiance of sub-pixel target

L D S / Gi i i i mWcm sr m2 1 1

L T c exp c T 1i B 15

2 B , / / , K

DN => Spectral Radiance

Spectral Radiance => Brightness Temperature

Brightness Temperature => Kinetic Temperature T TB

1 / 4kin K

Target Size m 2 T band - 5 K T band -7 K

14 x1410 x10

10501300

10001250

75

Richter et al. 1986


Wiesn in Munich - Optical versus Thermal Data

Dais 7915 Band 74, 9µm20.09.1994, ~11.00hrs

Airplane Imagery Real Color (2009?)

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