karel martínek [email protected] karel.martinek ... · karel martínek...
TRANSCRIPT
Remote sensing
introduction
Karel Martínek
electromagnetic radiation, sensing, images
Remote sensing
2
electromagnetic radiation
3
interactions with the atmosphere
4
scatteringabsorption
5
interactions with Earth surface materials
6
passive vs. active sensors
7
images
8
raster image
pixel/cell
DN digital number
(pixel value)
panchromatic vs colour image
sensors
9
satellite characteristics
geostationary
near polar orbit
swath
10
geostationary
nadir point
revisit period
11
spatial resolution (pixel size)
12
low resolution =
= large pixel sizehigh resolution =
= small pixel size
spectral resolution
13
multispectral images - Landsat
14
15
hyperspectral images
radiometric resolution
2-bit vs. 16-bit image
16
revisit period
change analysis
geohazards
17
geohazards
airborne imaging
18
true color vs. infrared image
high spatial resolution, distortion of image
optical satellite sensors (~ 0,4 – 2,5 microns)
across-track scanners
along-track scanners
19
thermal sensing (~ 10 microns)
20
warming of surface, re-emission
of radiance
Landsat (Land observation satellite)
MSS – multispectral scanner
21
Landsat 7 ETM+, 7 spectral bands between 0.5 and 12.5 µm, NASA
ASTER, 14 spectral bands between 0.5 and 11.7 µm, NASA
22
Landsat (Land observation satellite)
TM – thematic mapper; ETM – enhanced thematic mapper
23
Landsat (Land observation satellite)
24
SPOT (Système Pour l'Observation de la Terre)
25
IRS - Indian Remote Sensing
26
high spatial resolution satellites (metres – dm)
QuickBird
WorldView
27
WorldView
IKONOS
Orbview
Formosat-2
Pleiádes
meteorological sensors
ocean
other
28
video
Lidar (LIght Detection And Ranging, cm resolution)
Radar (RAdio Detection And Ranging)
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