| Model ID: | M00004 | ||||||
| Model Name: | Snow DMRT-QCA Passive | ||||||
| Encoders: |
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| Key words: | Snow, brightness temperature, QCA, DMRT | ||||||
| Model Type: | Physical model | ||||||
| Latest Modified: | 2012/7/12 14:30:54 | ||||||
| Submission Date: | 2012/7/12 14:30:54 | ||||||
| Abstract: | Snow covered soil brightness temperature model based on QCA theory and DMRT | ||||||
| Equation: |
| 1 |
Name: Initial incident angle
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Parameter type: double
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Physic Entity: Initial incident angle，degree
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| 2 |
Name: Frequency
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Parameter type: double
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Physic Entity: Microwave frequency，GHz
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| 3 |
Name: End of incident angle
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Parameter type: double
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Physic Entity: End of incident angle, degree
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| 4 |
Name: Step of incident angle
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Parameter type: double
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Physic Entity: Step of incident angle, degree
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| 5 |
Name: Snow layer number
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Parameter type: double
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Physic Entity: Number of layer of snow
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| 6 |
Name: Snow density
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Parameter type: double
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Physic Entity: Snow density
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| 7 |
Name: Snow grain radius
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Parameter type: double
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Physic Entity: Snow grain radius
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| 8 |
Name: stickiness
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Parameter type: double
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Physic Entity: Stickiness parameter of QCA theory
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| 9 |
Name: Snow layer depth
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Parameter type: double
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Physic Entity: Snow layer depth
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| 10 |
Name: Soil moisture
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Parameter type: double
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Physic Entity: Soil moisture
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| 11 |
Name: Soil surface RMS height
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Parameter type: double
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Physic Entity: Soil surface RMS height, cm
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| 12 |
Name: Soil surface correlation length
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Parameter type: double
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Physic Entity: Soil surface correlation length
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| Title: | The Effects of Layers in Dry Snow on Its Passive Microwave Emissions Using Dense Media Radiative Transfer Theory Based on the QuasicrystallineApproximation (QCA/DMRT) | ||||||||||||
| Authors: |
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| Cited by: | IEEE Trans.Geosci. Remote Sensing | ||||||||||||
| Abstract: | A model for the microwave emissions of multilayer dry snowpacks, based on dense media radiative transfer (DMRT) theory with the quasicrystalline approximation (QCA), provides more accurate results when compared to emissions determined by a homogeneous snowpack and other scattering models. The DMRT model accounts for adhesive aggregate effects, which leads to dense media Mie scattering by using a sticky particle model. With the multilayer model, we examined both the frequency and polarization dependence of brightness temperatures (Tb's) from representative snowpacks and compared them to results from a single-layer model and found that the multilayer model predicts higher polarization differences, twice as much, and weaker frequency dependence. We also studied the temporal evolution of Tb from multilayer snowpacks. The difference between Tb's at 18.7 and 36.5 GHz can be 5 K lower than the single-layer model prediction in this paper. By using the snowpack observations from the Cold Land Processes Field Experiment as input for both multi- and single-layer models, it shows that the multilayer Tb's are in better agreement with the data than the single-layer model. With one set of physical parameters, the multilayer QCA/DMRT model matched all four channels of Tb observations simultaneously, whereas the single-layer model could only reproduce vertically polarized Tb's. Also, the polarization difference and frequency dependence were accurately matched by the multilayer model using the same set of physical parameters. Hence, algorithms for the retrieval of snowpack depth or water equivalent should be based on multilayer scattering models to achieve greater accuracy |
Equation