Retrieval Model of Infrared Surface Emissity Based On
NOAA Satellite Data
relation of e between two channels
Statistically, for rock and soil, there
is a ratio between two average spectral
reflectance (NOAA channel 4 and 5).
r4/
r5=
a
ať2
And
e4=1-
r4,
e5=1-
r5 ,
So we have:
e5
=1-(1-
e4
)/
a (3)
Accurate
a can be calculated directly
from reflectance spectrum.
Emissivity model
From (1), (2), (3), we have:
e4=R(4/5)
/(
a b-R(4/5))
(4)
Where
R(4/5)=L(D4)/L(D5)=(L'(D4)-L
A4
)/(L'(D5)-L
A5)
B(T,
l4
)/ B(T,
l5)=
b
Initial
bcan be defined as 1.
From
e4 ,
e5
, (1) and (2), we have
T
41 and T
51, adopting
T
s1=(T
41
+T
51)/2.
Modification of emissivity
The emissivity and temperature
calculated above are not finally ideal
result. To get higher precision, we
should reiterate to remove the influence
of atmosphere and instrument until two
channels temperature are equal.
Conclusion
In this paper, we accomplish
research on retrieval model of surface
emissivity. Its specialty is to acquire
surface thermal radiation characteristic
by establishing retrieval model based
NOAA satellite data. Using this method
we can investigate quickly the thermal
radiation characteristic of any area in
real time The validity of model will be
presented for the future.
References
- w.m.chen, w.q.xia and g.y.chen, The
Satellite Aerography. Weather Press,
1993.
- F.Becker, and Z.L.Li, Infrared remote
sensing of surface temperature and
surface spectral emissivity, NATO
Asiseries. 1992.19.
- T.J.Schmugge, F. Becker and Z. L. Li,
Spectral emissivity variations observed
in airborne surface temperature
measurements, Remote Sens. Environ.
1991(34): 95-104.
Fang Yonghua received the B.S in
automatic conntrol from Nanjing
University of Aeronautics and
Astronautics in 1986 , the M.S and Ph.D.
degree in optics from Anhui Institute of
Optics & Fine Mechanics, Chinese
Academy of Sciences in 1992 and 1998
respectively.
Since 1986 he have been engaged in
research work on Remote Sensing.
Recently, his esearch interests are
remote sensing retrieval methods,
radiation calibration and atmosphere
correction .
Xun Yulong graduated in July,1966 as a
graduate student from Changchun
Institute of Optics & Fine Mechanics.
He is a senior research fellow, tutor of
student for Ph.D..
He has been engaged in optics for
tens years. Recently, his research
interests are laser induced fluorescent
remote sensing, application of pattern
recognition, neural network and wavelet
techniques to recognition of remote
sensing spectra & image, and laser lidar.
