1. Become “spectrally aware” !
UW AERIbago
1.0
Grass Vegetation
12 m
Emissivity
Bare Soil
ARM SGP site is dominated by two land cover types “grass vegetation” and “bare soil”.
U. of Wisconsin measured the IR emissivity at high spectral resolution.
9 m
4 m
0.75
500
Wavenumber (cm-1)
3000

2. Validation Case Study: Southern Great Plains Site
S-HIS Observation
Tskin = K
Best fit to Tskin when spectral variance in emissivity is minimum.

3. Aircraft validation measurements are consistent with a linear combination of vegetation and bare soil.
Pure Vegetation
1.0
Aircraft
S-HIS
LSE
S-HIS OBS
Bare Soil
12 m
9 m
0.85
Wavenumber (cm-1)

4. Skin Temperature & Surface Emissivity
Infrared Radiative Transfer Equation (lambertian surface)
Surface Emission
Surface
Reflection
Ndn (60deg)
Skin Temperature & Surface Emissivity

5. Emissivity Survey
ARM SGP site is dominated by two land cover types “pasture” and “wheat”.
Notice that the measured wheat field emissivity can be approximated by a linear combination of pure scene types; bare soil and grass.

6. IR Land Surface Signatures: QUARTZ
0.5
Solid
Coarse
> 75 m R
> 2 m & < 75 m
Fine
0.0
0.5 R
0.0
QUARTZ Reflectivity (JPL Spectral Library from Lab Tests).

7. IR Land Surface Signatures: QUARTZ
1.0
1-R
Solid
Coarse
> 75 m
> 2 m & < 75 m
0.5
Fine
1.0
1-R
0.5
QUARTZ Emissivity (JPL Spectral Library from Lab Tests).

8. IR Land Surface Signatures: JPL Library
0.5
Granite
Sandy Loam R
Quartz (coarse grain)
0.0
0.5 R
0.0
QUARTZ Emissivity (JPL Spectral Library from Lab Tests).

9. IR Land Surface Signatures: JPL Library
1.0
1-R
0.5
1.0
1-R
Granite
Sandy Loam
Quartz (coarse grain)
0.5
QUARTZ Emissivity (JPL Spectral Library from Lab Tests).