karel martínek karel.martinek@natur.cuni.cz karel.martinek ... · karel martínek...

Remote sensing

introduction

Karel Martínek

karel.martinek@natur.cuni.cz

karel.martinek@geology.cz

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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