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On line servers : Model Codes (3W)

Servers devoted to the distribution of remote sensing codes




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new PoMoS & GloMo

PoMoS & GloMo are two complementary modules developed in CESBIO for deterministic modeling of poorly known and partially observed systems. These modules are simultaneously based on a complex system approach and on theory of dynamical systems. Mangiarotti S., Coudret R., Drapeau L.

  • PoMoS ( Polynomial Model Search)

    aims to build a network of deterministic links between observed variables. It is based on an evolutionary algorithm combined with a least square approach.

  • GloMo ( Global Modelling)

    aims to identify global low-dimensional models from one single time series (Gouesbet & Letellier, 1994).

Although independent in their construction, these two modules have been designed in order to be used in synergy. Other modules are in development with the aim to progressively build a platform of analysis, modeling and forecasting.

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Figure: Reconstruction in the phase space of the signal of rainfed wheat in semi-arid region: observation by remote sensing (black line), simulation obtained with PoMoS & GloMo (red).

Reference: G. Gouesbet & C. Letellier, Global vector field reconstruction by using a multivariate polynomial L2-approximation on nets, Physical Review E, 49(6), 4955-4972, 1994.

More details : PoMoS-package aims to determine from a set of N time series the optimal polynomial structure of a model built on first-order ordinary differential equations. The core of the package is based on the poMoS function: an evolutionary algorithm combined with a least square fitting. Optimality is estimated with AIC (Akaike, 1974) or AIC-like criterions. Although efficient in its selection, the identification of the optimal structure cannot be guaranteed. Therefore, both selected and rejected models are reconsidered after optimal solutions are obtained from the evolutionary algorithm for another analysis. This analysis is based on a statistical evaluation of the regressors' quality. PoMoS is valitaded by the Comprehensive R Archive Network (CRAN)

In order to access to the code from Sylvain Mangiarotti at CESBIO, we suggest you to fill this registration form and explain in a few words what would be the applications. You will be also informed of further development and updates.

more informations...

 

 

newSimple Algorithm For Yield Estimate (SAFY)

SAFY model was developed with the aim of taking into account the main processes of development and growth of annual plants while limiting the number of parameters needed for their description, in order to facilitate the spatial results.

Duchemin B;, Maisongrande P., Boulet G. and Benhadj I. : A simple algorithm for yield estimates: Evaluation for semi-arid irrigated winter wheat monitored with green leaf area index. Environmental Modelling & Software 23 (2008) 876-892

The dynamics of the vegetation is apprehended by the theory of efficiencies of Monteith (1972) for photosynthesis and biomass production.

The model simulates the temporal evolution of the green leaf area index ('Leaf Area Index', observable by optical remote sensing) of dry phytomass and grain yield from relatively simple formalisms (7 main equations with 14 parameters). To date, it has been tested on wheat, corn, soybean and sunflower.

This model has been developed under the SUDMED project coordinated by CESBIO with specific support of IRD (Research Institute for Development ') and European program IRRIMED. Thank you kindly fill out the form, which will allow you to download the source code.

 

new Simulation of satellite Signal in the Solar Spectrum :(SMAC)

a simplified method for the atmospheric correction of satellite measurements in the solar spectrum
The present SMAC software has been developed at Cesbio by B. Berthelot and G. Dedieu in the context of the SPOT4-VEGETATION program. The calculation of the coefficients for the different sensors was funded by CNES, and managed by B. Berthelot (NOVELTIS). We thank P.Henry, F. Cabot and O. Hagolle from CNES for their help, as well as G.Saint and X. Passot (CNES, VEGETATION program)

  • Rahman H. and Dedieu G. : SMAC: a simplified method for the atmospheric correction of satellite measurements in the solar spectrum, International Journal of Remote Sensing, 1994, vol.15, No.1, 123-143.

Once you have filled out the form you can download the source code which will allow you to calculate the value of the surface reflectance measured at the top of the atmosphere for your choice sensor for each pixel. This method is mainly used to correct the data bases acquired by large view sensors with high temporal repetitiveness. There is a set of coefficients for each spectral band and sensor.

 

newDiscrete Anisotropic Radiative Transfer (DART)

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DART model is developed at CESBIO since 1992. It was recently patented (PCT/FR02/01181). It simulates radiative transfer in realistic complex 3-D scenes; i.e. , urban and/or natural Earth landscape possibly with topography and atmosphere. It uses an innovative ray tracing method that combines the exact kernel and discrete ordinate techniques, simultaneously in several wavelengths, from the visible to the thermal infrared domains (0.3mm - 15mm).
Since its first release in 1996, it was greatly improved in terms of accuracy (more accurate multiple scattering simulation, simulation of tree branches, use of a Monte Carlo module for reference purposes, etc.) and range of applications (direct simulation of computer scenes from land cover maps, etc.). Moreover, recently, Magellium Corp., a subcontractor of French Space Center (CNES) improved its code and Graphic User Interface for obtaining a professional DART release that works under Linux and Windows systems.
Access to the DART software domain ;
DART can be freely used for scientific or educational purposes. For that, an agreement must be signed between Paul Sabatier University and a responsible of the scientific/educational body.

 


     
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