-
Notifications
You must be signed in to change notification settings - Fork 20
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Inclusion of Vant effective permittivity for sea ice at L-band #22
Comments
Since the Vant formulation is an effective permittivity formulation, the procedure is very different from a raw material permittivity that is used to describe background and scatterers's permittivity. In fact, you need to 1) move this formulation in a file with a name stating that it is a mixing formula, for instance saline_ice_mixing_formula.py (based on the file permittivities/snow_mixing_formula.py for an example) and 2) redefine a new electromagnetic model (emmodel) which is possible in SMRT, but a detailed understanding of the implications is first necessary.
2a) One approach consists in really creating a new emmodel. For that copy a file like iba.py -> my-iba-derived-model.py and edit as much as you want. Then use this new model with:
2b) The second approach uses a function called "derived_IBA" (defined in emmodels/iba.py, and the same apply to SCE) and more generally derived_EMModel (defined in emmodels/common.py) which automatically creates a derived IBA model using a different effective_permittivity_model function.
In your case, I'd recommend to use:
|
In order to include the Vant effective permittivity formulation for sea ice (Vant et al. 1978, "The complex-dielectric constant of sea ice at frequencies in the range 0.1–40 GHz", only for L-band as it employs distinct coefficients for each frequency), I'm facing some difficulties. I have successfully incorporated the permittivity function into the saline_ice.py file. However, I'm encountering some ambiguity regarding its usage within the make_medium function. After reviewing the code, it seems that both the "ice_permittivity_model" (for firstyear ice) and the "saline_ice_permittivity" (for multiyear ice) determine the background permittivity, which is then mixed with the scatterers. The Vant formulation is empirical, and it computes the permittivity of the saline ice by itself (it doesn't have to be then mixed).
The text was updated successfully, but these errors were encountered: