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INTRODUCTION REMOTE SENSING
Introduction Geo-Information Science (GRS-10306)
Remote Sensing --> RS
EARTHOBSERVATION
RS is a tool; one of the sources of information !Earth
Sensor ata distance
EM energy
GIS Geographical Information System
Well-considered combination of mutually referring data sets of various kinds of position-bound thematic data(database), software inclusive
Requirement:the information layersmatch geometrically
==> OVERLAY STRUCTURE
1. topography
2. soils3. geology4. precipitation5. land cover6. vegetation7. remote sensing data8. surface temperature9. hydrology10. population11. nature conservation12. environment13. digital terrain model14. topographical map15. -------------------16. -------------------17. -------------------
rasterdata
GIS file:field data
(point measurements)
vectordata
Meteosat: meteorological satellite
Meteosat image of Europe
Wageningen, Thematic Mapper Band 4 5 3
Rotterdam harbour, daytime
Rotterdam harbour, nighttime
The remote sensing system
A = source
B = atmosphere
C = object
D = sensor
E = reception
F = data analysis
G = final product
Source of EM radiation100
10-1
10-2
10-3
10-4
0.2 0.5 2 101.0 5 20
radiation (Wcm-2 µm-1)
wavelength (µm)
REFLECTION EMISSION
emitted
thermal radiation
reflected
solar radiation
curves for an “average”object on Earth
EM Spectrum and Windows
200 µµµµm0.3 0.6 1.0 5.0 10 50 10m100 1mm 1cm 1m
200 µµµµm0.3 0.6 1.0 5.0 10 50 10m100 1mm 1cm 1m
multispectral scanners
microwavewindow
emission
opticalwindow
lidar
reflection
photography
human eye
mic
row
aves
microwave radiometry
blocking effect of atmosphere
radar
atm
osph
eric
tran
smitt
ance
UV
blue
gree
nre
d
NIR
MIR
MIR
TIR TIR
thermal scanners
VIS
wavelength
100
0
Active <-> Passive
RS using radiation emitted by objects:(PASSIVE)
RS using reflected solar radiation:(PASSIVE)
ACTIVE RS:
Principles imaging sensor systems
Pushbroom scannerWhiskbroom scanner
digital recordinganalogue recording digital recording
scanning mirrorshutter
“point” detector
aerial image plane line array detector
imaging optics imaging optics
Camera(aerial photography)
imagingoptics
The position of the spectral bands of some Remote Sensing sensor systems in the optical window
λwavelength (µm)
red middle-
infrared
near-
infraredblue
gree
n
dry soil
waterwet soil
vegetation
reflectance (%)
SPOT HRG Panchromatic
Pan: IKONOS, Quickbird, GeoEye, WorldView
Meteosat
NOAA AVHRR
Landsat TM
40
20
00.8
60
0.4 1.2 1.6 2.0 2.4
SPOT HRG multispectral
Multispectral: IKONOS, Quickbird, GeoEye, WorldView
Image Processing OptionsTape/DVD/CD: Screen:latent image → Visualization → picture 1
picture 2--------------
picture nOptions:e.g. spectral band selection filtering
displaying band composites band ratioingcontrast modification vegetation index computationhistogram equalization classificationgrey scale enhancement texture analysiscolour assignment segmentationdensity slicing geometric correctionprincipal componentstransformation
Example TM-image, band 4-3-2 (R,G,B)
RS Properties
Moreover:
� overview region
� differences and coherence
� variety of sensors, techniques, processing algorithms
� reproducible analysis
� in addition to conventional mapping
� specified data for application
� up to date information
� co-operation of human knowledge and machine operations
� capability of monitoring with time series of data
� reveals changes (change detection)
� the invisible becomes visible
� objective and quantitative data
� extrapolation of point measurements
� open up inaccessible regions
� integration with GIS
� Synopsis
� Flexibility
� Actuality
� Interactivity
� Dynamics
MERIS image of Europe
Satellite based land cover classification
Dutch land cover data base LGN5
LGN5 detail The Hague - Rotterdam
Global land cover classification - MODIS
254Unclassified
16Barren or Sparsely Vegetated
15Snow and Ice
14Cropland/Natural Vegetation Mosaic
13Urban and Built-Up
12Croplands
11Permanent Wetlands
10Grasslands
9Savannas
8Woody Savannas
7Open Shrubland
6Closed Shrubland
5Mixed Forest
4Deciduous Broadleaf Forest
3Deciduous Needleleaf Forest
2Evergreen Broadleaf Forest
1Evergreen Needleleaf Forest
0Water
255Fill Value
ColorClassLand Cover
254Unclassified
16Barren or Sparsely Vegetated
15Snow and Ice
14Cropland/Natural Vegetation Mosaic
13Urban and Built-Up
12Croplands
11Permanent Wetlands
10Grasslands
9Savannas
8Woody Savannas
7Open Shrubland
6Closed Shrubland
5Mixed Forest
4Deciduous Broadleaf Forest
3Deciduous Needleleaf Forest
2Evergreen Broadleaf Forest
1Evergreen Needleleaf Forest
0Water
255Fill Value
ColorClassLand Cover
Primary Productivity - June 2005
Primary Productivity – December 2004
Perspective view of the Aletsch glacier (CH)