Chapter 13 — Question 5
For a sea level summer image (Landsat 5), the following atmospheric parameters
are determined with MODTRAN4:
•
The atmospheric transmissivity
τ
is 0.7.
•
The upwelling radiance L ↑ is 2.4 W m
−
2
sr
−
1
µ
m
−
1
.
•
The downwelling radiance L ↓ is 3.7 W m
−
2
sr
−
1
µ
m
−
1
.
The broad-band surface emissivity
ε
is 0.98 and the radiance L
sat
observed at the
satellite is 8.82 W m
−
2
sr
−
1
µ
m
−
1
.
- Calculate the black-body radiance L
BB
.
- Determine the surface radiant and kinetic temperatures.
Answer
If you transform equation 13.8, you can isolate L
BB
on one side. Then fill in the
given values.
Result:
L
BB
= 9.283 W m
−
2
sr
−
1
µ
m
−
1
T
rad
= 299.2 K (using equation 13.7)
T
kin
= 276.0 K (using equation 13.6)