Post on 08-Aug-2020
Introduction Remote Sensing
GIMA: Geographical Information Managementand Applications
Electromagnetic (EM) spectrum
Remote sensing platforms
Remote sensing ≡ Earth observation
RS is a tool; one of the sources of information !Field
Sensor ata distance
EM radiation
Satellite image flooding the Netherlands:Rhine & Waal rivers on 8 January 2018
Satellite image flooding the Netherlands:Red are flooded areas
Satellite image Terschelling 26 May 2018
6
Drought effect Terschelling 15 July 2018
7
Temperature anomaly, June 30 – July 9, 2015
July 2017 was the hottest month on record
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. topography2. 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
Rotterdam harbour, daytime / nighttime
The remote sensing system
A = sourceB = atmosphereC = objectD = sensorE = receptionF = data analysisG = final product
EM Spectrum and Windows
200 µm0.3 0.6 1.0 5.0 10 50 10m100 1mm 1cm 1m
200 µm0.3 0.6 1.0 5.0 10 50 10m100 1mm1cm 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
wavelength (µm)
red middle- (shortwave)
infrarednear-
infraredblue
gree
n
dry soil
water
wet soil
vegetation
refle
ctan
ce (%
)
40
20
00.8
60
0.4 1.2 1.6 2.0 2.4
Object interaction - reflectance
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
Position of spectral bands
MeteosatNOAA AVHRR
wavelength (µm)
red middle-
infrarednear-
infraredblue
gree
n
dry soil
waterwet soilvegetationre
flect
ance
(%)
40
20
00.8
60
0.4 1.2 1.6 2.0 2.4
Pan: IKONOS, Quickbird, GeoEye, WorldViewMultispectral: IKONOS, Quickbird, GeoEye, WorldView
Proba-V
Sentinel-2 MSI8
42 3
Landsat OLIpan
2 3 4 5
Image Processing Options
Tape/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 analysis colour assignment segmentationdensity slicing geometric correction
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
LGN 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
AVHRR-NDVI time series 1981-2012
Credit: R. de Jong
Some current RS developments
What’s up next?
Next topics:
• Spectral signature• Multispectral scanning• Microwave remote sensing• Image pre-processing• Digital image processing
See: www.geo-informatie.nl/courses/gima_rs