Upload
phyllis-mcneil
View
24
Download
3
Tags:
Embed Size (px)
DESCRIPTION
Thursday, 12 March. Lecture 20 – review Labs: questions Next Wed – Final: 18 March 10:30-12:20. physical basis of remote sensing spectra radiative transfer image processing radar/lidar thermal infrared applications. What is remote sensing? Measurement from a distance - PowerPoint PPT Presentation
Citation preview
Lecture 20 – review
Labs: questions
Next Wed – Final: 18 March 10:30-12:20
Thursday, 12 March
- physical basis of remote sensing- spectra- radiative transfer- image processing- radar/lidar-thermal infrared- applications
What is remote sensing?
Measurement from a distance
Wide range of wavelengths
Hazardous locales
Images
pixels
DNs
scanners, orbits
image geometry, parallax
resolution
color vs. intensity and texture
The spectrum and wavelength regions
Units of radiance, irradiance, spectral radiance
Color mixing, RGB false color images
Color is due to absorption: e-kz (Beer Law)
Hue, saturation, intensity
Radiative transfer
Sunlight, atmospheric absorption & scatteringRayleigh, Mie, Non-selective
Reflection – 1st surface (Fresnel’s Law), volume
Planck function: -5 (exp(c/T)-1)
Atmospheric windows
DN = g·(e·r · i·Itoa·cos(i)/ + e· r·Is↓/ + Ls↑) + o
r I cos(i)/: Lambert’s law
When do you need atmospheric compensation?dark object subtractionModtran model
Interaction of Energy and Matter
Rotational absorption (gases)
Electronic absorption Charge-Transfer Absorptions
Vibrational absorption
Spectra of common Earth-surface materials
Image processing algorithmsradiometrygeometrySpectral analysisStatistical analysisModeling
Algorithms:RatioingSpectral mixture analysis
max number of endmembers = n+1shade
NDVI
Classification – spectral similaritysupervised vs. unsupervisedmaximum likelihood vs parallelipipedthemes & land usevalidationconfusion matrix
Confusion matricesWell-named. Also known as contingency tables or error matricesHere’s how they work…
Training areasA B C D E F
A
B
C
D
EF
Cla
ssif
ied
data
Col sums
Row sums
Grand sum
All non diagonal elementsare errors
Row sums give “commission”errors
Column sums give “omission” errors
Overall accuracy is the diagonal sum over the grand total
This is the assessment only for the training areas
What do you do for the rest of the data?
p 586, LKC 6th
480 0 5 0 0 0 485
0
0
0
0
0
0
0
0
480
52
16
68 1992
0 20 0 0 72
Crater counting – relative dating on the moon and Mars
Forest remote sensing
SMA in forest studiesShade endmember vs. canopy vs. topography
What can Lidar do for forest characterization?
LayoverShadowsPolarizationSensitivity to
- dielectric- roughness
ih
cos8
Corner reflectorsInterferometry
LiDAR
Thermal
Planck’s Law: R = (() ) c1-1 -5[exp(c2 -1TT-1 )-1] -1
Emissivity
Blackbody radiation
What compositions can be What compositions can be determined in the TIR?determined in the TIR?
Mostly vibrational resonance, not electronic processestherefore, relatively large molecules
Silicate minerals (SiO4-4); quartz (SiO2)
Sulfates (SO4=); sulfur dioxide (SO2)
Carbonates (CO3=); carbon dioxide (CO2)
Ozone (O3) Water (H2O)Organic molecules
Mauna Loa, Hawaii
MASTER VNIRdaytime
ASTER TIR,daytime
MTI TIR,nighttime