MODTRAN tape7输出文件解释

出处http://twiki.cis.rit.edu/twiki/bin/view/Main/ModtranTape7ColumnDescriptions

MODTRAN TAPE7 Column Descriptions

This page is an attempt to document our interprettation of the various columns generated by MODTRAN. This output will be different depending on the geometry specified by the user, but initial documentation will be for a sensor looking down to the ground (ModtranH1vsH2).
Subsequent geometries will be detailed as we encounter specific examples.

MODTRAN
TAPE7 Column Descriptions

Current
Interpretation of MODTRAN tape7 output
LOWTRAN7
Description of tape7 output
and
COMMENTS

Current Interpretation of MODTRAN

tape7

output

The following description is based on a sample output from MODTRAN of the following file.

tape7.scn:
MODTRAN

tape7.scn

file from which the data was plotted

The same column descriptions also apply to

tape7

.
The difference between the

tape7

file and the

tape7.scn

file
is that the former is in [1/cm] which is the native unit of MODTRAN output prior to MODTRAN3. The output wavelength for the

tape7.scn

file
can be user-specified. In this example, the

tape7.scn

output file has wavelengths specified in
[microns] and radiance in [W/sr/cm^2/um].

The following columns are labelled as follows with the definition/description. The plots that correspond to the various spectra was generated using the following

tape5

file.

tape5:
MODTRAN tape5 file that created the plots on this page

The conditions are for an 18% reflector being imaged at AVIRIS altitudes for a Mid-latitude Summer atmosphere (MLS). This particular card deck is an MLS version of the
card deck with radiosonde profiles for the day of the AvirisRochesterEmbayment19990520 collect.

The resulting

tape7.scn

file has been converted to the ENVI spectral library files

tape7.sli:
ENVI Spectral Library containing the

tape7.scn

data and
tape7.sli.hdr:
ENVI Spectral Library header file

FREQ MCRNThe band-center wavelength of the given spectral point entry for the following radiometric parameters.

TRANThe transmission from the target to the sensor, i.e.,

tau2

in the Big
Equation.

Plot of TRAN Column [Unitless]:



PTH THRMLThe thermal emission term of the path radiance (neglible in the reflective region)

Plot of PTH_THRML Column [W/(sr cm^2 um)]:



THRML SCTThe thermal scattering term of the path radiance (negligible in the reflective region)

SURF EMISRadiant emission of the target as a function of its temperature and emissivity

Plot of SURF_EMIS Column [W/(sr cm^2 um)]:



SOL SCATThe solar multiple-scattered radiance term of the path radiance.

Plot of SOL_SCAT Column [W/(sr cm^2 um)]:



SING SCATThe solar single-scattered radiance term of the path radiance.

Plot of SING_SCAT Column [W/(sr cm^2 um)]:



GRND RFLTThe total ground reflected radiance. For a target of reflectivity 1.0, this term would be

(Direct Reflected Radiance) + (Diffuse Reflected Radiance)

or %$\frac{E^{'}_{s \lambda}\cos\theta
\tau_1(\lambda)\tau_2(\lambda)}{\pi}+L_{d \lambda} \tau_2$% in the Big
Equation

Plot of GRND_RFLT Column [W/(sr cm^2 um)]:



DRCT RFLTThis is the direct reflected radiance. For a target of reflectivity 1.0, this term would be

(Direct Reflected Radiance)

or %$\frac{E^{'}_{s \lambda}\cos\theta \tau_1(\lambda)\tau_2(\lambda)}{\pi}$%
in the Big
Equation

Plot of DRCT_RFLT Column [W/(sr cm^2 um)]:



TOTAL RADThis is the total radiance reaching the sensor which should be equivalent to %$\frac{E^{'}_{s \lambda}\cos\theta \tau_1(\lambda)\tau_2(\lambda)r(\lambda)}{\pi} + L_{d \lambda}\tau_2 r(\lambda) + L_{u\lambda}$% in the Big
Equation. Because of the simplified form of this equation, adjacency and environmental effects may not represented in the equation resulting in a larger value for TOTAL RAD computed by MODTRAN.

Plot of TOTAL_RAD Column [W/(sr cm^2 um)]:



REF SOLThis is SOL@OBS multiplied by tau1 and tau2. This column is most likely in units of irradiance [W/cm^2], not radiance, since SOL@OBS is in irradiance units and tau1*tau2 is unitless.
( N.B. Found some old notes attributed to Lee Sanders that REF_SOL for the version we were using back during his research, was EsTau1Tau2 -- RolandoRaqueno -
08 Mar 2007)

Plot of REF_SOL Column [W/(cm^2 um)]:



SOL@OBSThis is the downwelling solar irradiance at the altitude of the observer. This value should be DRCT RFLT if we move the target to the height of the sensor. N.B. The
units should be Irradiance in the plot -- RolandoRaqueno -
06 Nov 2006

Plot of SOL@OBS Column
[W/(cm^2 um)]:

<img width="360" alt="Plot of <a href=" mailto:sol@obs"="" style="vertical-align: text-bottom; border: 0px;">SOL@OBS Column [W/(cm^2 um)]" src="/twiki/pub/Main/ModtranTape7ColumnDescriptions/SOL_OBS.jpg" height="255" />

DEPTHNegative Log of the transmittance column TRAN

Plot of DEPTH Column [1/m] or [1/km], not sure of this ???: