RT1 model documentation

Welcome to the documentation for the RT1 python package!

The rt1_model package is a python implementation for the RT1 bistatic (first order) scattering radiative transfer model as described in Quast and Wagner [QW16] Quast et al. [QACW19]. that can be used to simulate the scattered radiation from a rough surface covered by a tenuous distribution of particulate media.

RT1 hereby provies a flexible framework to parameterize the scattering properties of the surface and volume layer via bistatic distribution functions.

The rt1_model package provides the following core features:

  • An object-oriented interface to easily setup, evaluate and analyze RT1 model specifications.

  • An (extensible) set of volume- and surface scattering distribution functions and capabilities to use arbitrary linear combinations thereof.

  • Fast numeric evaluation of the model up to first order (e.g. double-bounce) contributions.

  • Capabilities to evaluate the Jacobian with respect to arbitrary model parameters (for model parameter optimization).

RT1 model overview

Fig. 1 Illustration of the scattering contributions considered in the RT1 model (from [QWBMV23])

Note

RT1 is provided as open-source software, hoping that it will help you in your research. The developers would very much appreciate to receive feedback how the model is used. Also contributions and suggestions for further improvements are highly welcome.

Please read the LICENSE agreement related to this software which gives you much flexibility to (re)use the code. Currently we use the APACHE-2.0 license.

When you are using RT1 as part of your publications, please give the developers credit by adding a citation for the source-code doi_img and to the papers Quast and Wagner [QW16], Quast et al. [QACW19]:

Additional information on how to use the RT1 model for soil-moisture retrievals can be found in Quast et al. [QWBMV23]:

[QACW19] (1,2)

Raphael Quast, Clément Albergel, Jean-Christophe Calvet, and Wolfgang Wagner. A generic first-order radiative transfer modelling approach for the inversion of soil and vegetation parameters from scatterometer observations. Remote Sensing, 11(3):285, February 2019. doi:10.3390/rs11030285.

[QW16] (1,2)

Raphael Quast and Wolfgang Wagner. Analytical solution for first-order scattering in bistatic radiative transfer interaction problems of layered media. Applied Optics, 55(20):5379, July 2016. doi:10.1364/ao.55.005379.

[QWBMV23] (1,2)

Raphael Quast, Wolfgang Wagner, Bernhard Bauer-Marschallinger, and Mariette Vreugdenhil. Soil moisture retrieval from sentinel-1 using a first-order radiative transfer model—a case-study over the po-valley. Remote Sensing of Environment, 295:113651, September 2023. doi:10.1016/j.rse.2023.113651.